CINXE.COM

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN" "http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd">     <html xml:lang="en" lang="en" dir="ltr" >    <head profile="http://www.w3.org/1999/xhtml/vocab"> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <link rel=”apple-touch-icon-precomposed” href=”/sites/default/themes/bmj/the_bmj/img/icon.png”/> <meta http-equiv="X-UA-Compatible" content="IE=edge">  <link rel="dns-prefetch" href="//static.polldaddy.com" /> <link rel="dns-prefetch" href="//ajax.googleapis.com" /> <link rel="dns-prefetch" href="//crossmark-cdn.crossref.org" /> <link rel="dns-prefetch" href="//d1bxh8uas1mnw7.cloudfront.net" /> <link rel="dns-prefetch" href="//www.google.com" /> <link rel="dns-prefetch" href="//scholar.google.com" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <link rel="shortcut icon" href="https://www.bmj.com/sites/default/themes/bmj/the_bmj/favicon.ico" type="image/vnd.microsoft.icon" /> <link href="//netdna.bootstrapcdn.com/font-awesome/4.0.3/css/font-awesome.css" rel="stylesheet" media="all" type="text/css" /> <link rel="alternate" type="text/plain" title="Full Text (Plain)" href="/content/314/7074/112.full.txt" /> <meta name="type" content="article" /> <meta name="category" content="research-article" /> <meta name="HW.identifier" content="/bmj/314/7074/112.atom" /> <meta name="HW.pisa" content="bmj;314/7074/112" /> <meta name="DC.Format" content="text/html" /> <meta name="DC.Language" content="en" /> <meta name="DC.Title" content="Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies" /> <meta name="DC.Identifier" content="10.1136/bmj.314.7074.112" /> <meta name="DC.Date" content="1997-01-11" /> <meta name="DC.Publisher" content="British Medical Journal Publishing Group" /> <meta name="DC.Rights" content="© 1997 BMJ Publishing Group Ltd." /> <meta name="DC.AccessRights" content="restricted" /> <meta name="DC.Relation" content="10.1136/bmj.314.7074.0d" /> <meta name="DC.Relation" content="10.1136/bmj.333.7561.214" /> <meta name="DC.Relation" content="10.1136/bmj.e8539" /> <meta name="DC.Relation" content="10.1136/bmj.323.7319.1000" /> <meta name="DC.Description" content="Objective: To determine the quantitative importance of dietary fatty acids and dietary cholesterol to blood concentrations of total, low density lipoprotein, and high density lipoprotein cholesterol. Design: Meta-analysis of metabolic ward studies of solid food diets in healthy volunteers. Subjects: 395 dietary experiments (median duration 1 month) among 129 groups of individuals. Results: Isocaloric replacement of saturated fats by complex carbohydrates for 10% of dietary calories resulted in blood total cholesterol falling by 0.52 (SE 0.03) mmol/l and low density lipoprotein cholesterol falling by 0.36 (0.05) mmol/l. Isocaloric replacement of complex carbohydrates by polyunsaturated fats for 5% of dietary calories resulted in total cholesterol falling by a further 0.13 (0.02) mmol/l and low density lipoprotein cholesterol falling by 0.11 (0.02) mmol/l. Similar replacement of carbohydrates by monounsaturated fats produced no significant effect on total or low density lipoprotein cholesterol. Avoiding 200 mg/day dietary cholesterol further decreased blood total cholesterol by 0.13 (0.02) mmol/l and low density lipoprotein cholesterol by 0.10 (0.02) mmol/l. Conclusions: In typical British diets replacing 60% of saturated fats by other fats and avoiding 60% of dietary cholesterol would reduce blood total cholesterol by about 0.8 mmol/l (that is, by 10-15%), with four fifths of this reduction being in low density lipoprotein cholesterol. #### Key messages" /> <meta name="DC.Contributor" content="Robert Clarke" /> <meta name="DC.Contributor" content="Chris Frost" /> <meta name="DC.Contributor" content="Rory Collins" /> <meta name="DC.Contributor" content="Paul Appleby" /> <meta name="DC.Contributor" content="Richard Peto" /> <meta name="article:published_time" content="1997-01-11" /> <meta name="article:section" content="Paper" /> <meta name="citation_title" content="Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies" /> <meta name="citation_abstract" lang="en" content="<h3>Abstract</h3> <p><b>Objective:</b> To determine the quantitative importance of dietary fatty acids and dietary cholesterol to blood concentrations of total, low density lipoprotein, and high density lipoprotein cholesterol.</p><p><b>Design:</b> Meta-analysis of metabolic ward studies of solid food diets in healthy volunteers.</p><p><b>Subjects:</b> 395 dietary experiments (median duration 1 month) among 129 groups of individuals.</p><p><b>Results:</b> Isocaloric replacement of saturated fats by complex carbohydrates for 10% of dietary calories resulted in blood total cholesterol falling by 0.52 (SE 0.03) mmol/l and low density lipoprotein cholesterol falling by 0.36 (0.05) mmol/l. Isocaloric replacement of complex carbohydrates by polyunsaturated fats for 5% of dietary calories resulted in total cholesterol falling by a further 0.13 (0.02) mmol/l and low density lipoprotein cholesterol falling by 0.11 (0.02) mmol/l. Similar replacement of carbohydrates by monounsaturated fats produced no significant effect on total or low density lipoprotein cholesterol. Avoiding 200 mg/day dietary cholesterol further decreased blood total cholesterol by 0.13 (0.02) mmol/l and low density lipoprotein cholesterol by 0.10 (0.02) mmol/l.</p><p><b>Conclusions:</b> In typical British diets replacing 60% of saturated fats by other fats and avoiding 60% of dietary cholesterol would reduce blood total cholesterol by about 0.8 mmol/l (that is, by 10-15%), with four fifths of this reduction being in low density lipoprotein cholesterol.</p><h3>Key messages</h3><p>The quantitative importance of diet to blood cholesterol remains uncertain because non-experimental dietary studies in community subjects are unreliable and experimental (“metabolic ward”) studies have been too small to be separately reliable</p><p>We conducted a meta-analysis of 395 published, metabolic ward experiments of the effects of various dietary lipids on blood cholesterol</p><p>Isocaloric increases in saturated fat intake were associated with increases in total and low density lipoprotein cholesterol and smaller increases in high density lipoprotein cholesterol; increased polyunsaturated fat intake decreased total and low density lipoprotein cholesterol and increased high density lipoprotein cholesterol; monounsaturated fat had no significant effect on total and low density lipoprotein cholesterol but increased high density lipoprotein cholesterol</p><p>In the average British diet replacement of 60% of the saturated fat by other dietary fats and avoidance of 60% of dietary cholesterol would reduce blood cholesterol by about 0.8 mmol/l (that is, by 10-15%), with four fifths of this reduction being in low density lipoprotein cholesterol</p><p>The effect on vascular disease of a prolonged difference of 0.8 mmol/l in blood cholesterol concentration depends on the relative importance at different ages of the benefits of reducing low density lipoprotein cholesterol and the hazards of reducing high density lipoprotein cholesterol, which require further study</p>" /> <meta name="citation_journal_title" content="BMJ" /> <meta name="citation_publisher" content="British Medical Journal Publishing Group" /> <meta name="citation_publication_date" content="1997/01/11" /> <meta name="citation_mjid" content="bmj;314/7074/112" /> <meta name="citation_id" content="314/7074/112" /> <meta name="citation_public_url" content="https://www.bmj.com/content/314/7074/112" /> <meta name="citation_abstract_html_url" content="https://www.bmj.com/content/314/7074/112.abstract" /> <meta name="citation_full_html_url" content="https://www.bmj.com/content/314/7074/112.full" /> <meta name="citation_issn" content="0959-8138" /> <meta name="citation_issn" content="1468-5833" /> <meta name="citation_journal_abbrev" content="BMJ" /> <meta name="citation_doi" content="10.1136/bmj.314.7074.112" /> <meta name="citation_pmid" content="9006469" /> <meta name="citation_volume" content="314" /> <meta name="citation_issue" content="7074" /> <meta name="citation_num_pages" content="1" /> <meta name="citation_article_type" content="Research Article" /> <meta name="citation_section" content="Paper" /> <meta name="citation_firstpage" content="112" /> <meta name="citation_author" content="Robert Clarke" /> <meta name="citation_author" content="Chris Frost" /> <meta name="citation_author" content="Rory Collins" /> <meta name="citation_author" content="Paul Appleby" /> <meta name="citation_author" content="Richard Peto" /> <meta name="twitter:title" content="Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies" /> <meta name="twitter:card" content="summary" /> <meta name="twitter:description" content="Objective: To determine the quantitative importance of dietary fatty acids and dietary cholesterol to blood concentrations of total, low density lipoprotein, and high density lipoprotein cholesterol. Design: Meta-analysis of metabolic ward studies of solid food diets in healthy volunteers. Subjects: 395 dietary experiments (median duration 1 month) among 129 groups of individuals. Results: Isocaloric replacement of saturated fats by complex carbohydrates for 10% of dietary calories resulted in blood total cholesterol falling by 0.52 (SE 0.03) mmol/l and low density lipoprotein cholesterol falling by 0.36 (0.05) mmol/l. Isocaloric replacement of complex carbohydrates by polyunsaturated fats for 5% of dietary calories resulted in total cholesterol falling by a further 0.13 (0.02) mmol/l and low density lipoprotein cholesterol falling by 0.11 (0.02) mmol/l. Similar replacement of carbohydrates by monounsaturated fats produced no significant effect on total or low density lipoprotein cholesterol. Avoiding 200 mg/day dietary cholesterol further decreased blood total cholesterol by 0.13 (0.02) mmol/l and low density lipoprotein cholesterol by 0.10 (0.02) mmol/l. Conclusions: In typical British diets replacing 60% of saturated fats by other fats and avoiding 60% of dietary cholesterol would reduce blood total cholesterol by about 0.8 mmol/l (that is, by 10-15%), with four fifths of this reduction being in low density lipoprotein cholesterol. #### Key messages" /> <meta name="og-title" property="og:title" content="Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies" /> <meta name="og-url" property="og:url" content="https://www.bmj.com/content/314/7074/112" /> <meta name="og-site-name" property="og:site_name" content="The BMJ" /> <meta name="og-description" property="og:description" content="Objective: To determine the quantitative importance of dietary fatty acids and dietary cholesterol to blood concentrations of total, low density lipoprotein, and high density lipoprotein cholesterol. Design: Meta-analysis of metabolic ward studies of solid food diets in healthy volunteers. Subjects: 395 dietary experiments (median duration 1 month) among 129 groups of individuals. Results: Isocaloric replacement of saturated fats by complex carbohydrates for 10% of dietary calories resulted in blood total cholesterol falling by 0.52 (SE 0.03) mmol/l and low density lipoprotein cholesterol falling by 0.36 (0.05) mmol/l. Isocaloric replacement of complex carbohydrates by polyunsaturated fats for 5% of dietary calories resulted in total cholesterol falling by a further 0.13 (0.02) mmol/l and low density lipoprotein cholesterol falling by 0.11 (0.02) mmol/l. Similar replacement of carbohydrates by monounsaturated fats produced no significant effect on total or low density lipoprotein cholesterol. Avoiding 200 mg/day dietary cholesterol further decreased blood total cholesterol by 0.13 (0.02) mmol/l and low density lipoprotein cholesterol by 0.10 (0.02) mmol/l. Conclusions: In typical British diets replacing 60% of saturated fats by other fats and avoiding 60% of dietary cholesterol would reduce blood total cholesterol by about 0.8 mmol/l (that is, by 10-15%), with four fifths of this reduction being in low density lipoprotein cholesterol. #### Key messages" /> <meta name="og-type" property="og:type" content="article" /> <meta name="og:image" property="og:image" content="https://www.bmj.com/sites/default/files/highwire/bmj/388/8457.cover-source.jpg"/> <meta name="twitter:card" content="summary_large_image"><meta name="twitter:image" property="twitter:image" content="https://www.bmj.com/content/bmj/314/7074/112/F1.large.jpg"><meta name="twitter:title" content="Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies" /><link rel="alternate" type="application/vnd.ms-powerpoint" title="Powerpoint" href="/content/314/7074/112.ppt" /> <script>window.dataLayer = window.dataLayer || [];window.dataLayer.push({"page":{"hwTitle":"Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies","hwUrl":"https://www.bmj.com/content/314/7074/112","hwPath":"/content/314/7074/112","hwType":"journal page"},"user":{"hwMemberID":"","hwLoggedIntoInstitutionID":"","hwLoggedIntoInstitution":"","hwAccessUsageTerms":"guest","hwRegisteredUser":"no","hwHasFullTextAccess":"yes","hwEntitled":"no","mail":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"},"content":{"hwIssueDate":"1997-01-11","hwIssueDateTime":"1997-01-11 08:00:00","hwPublicationDate":"1997-01-11","hwPublicationDateTime":"1997-01-11 08:00:00","hwNlmArticleType":"research-article","hwDOI":"10.1136/bmj.314.7074.112","hwAuthors":"Robert Clarke,Chris Frost,Rory Collins,Paul Appleby,Richard Peto","hwContributors":"","hwIsEarlyRelease":"no","hwEissn":"1468-5833","hwPissn":"0959-8138","hwVolume":"314","hwIssue":"7074","hwArticleType":"Paper","hwTabView":"main_tab","hwViewType":"full","hwAccessType":"Free","hwOpenAccess":"no","hwFreeAccess":"yes","hwTaxonomy":"Diet","hwCorpusCode":"bmj","hwType":"article","hwSubtitle":null,"hwOverline":null,"hwPisaId":"bmj;314/7074/112","hwFirstPage":"112","hwLastPage":null,"hwIsLatestVersion":"yes","hwIsCurrentIssue":"no","hwIsOpenIssue":"no","hwHasFullText":"yes","hwHasPDF":"yes","hwParentTitle":"BMJ: 314 (7074)","hwElectronicPubDate":"1997-01-11","hwElectronicPubDateTime":"1997-01-11 08:00:00"}}); //--><!]]></script> <meta name="generator" content="Drupal 7 (http://drupal.org)" /> <link rel="canonical" href="https://www.bmj.com/content/314/7074/112" /> <link rel="shortlink" href="https://www.bmj.com/node/522410" /> <meta name="twitter:card" content="summary" /> <meta name="twitter:url" content="https://www.bmj.com/content/314/7074/112" /> <meta name="twitter:title" content="Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies" /> <title>Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies | The BMJ</title>   <link type="text/css" rel="stylesheet" href="https://www.bmj.com/sites/default/files/advagg_css/css__FiHqHoPUdv6CHw5dUEIfFV7jpYTgBb1JUncssjaxHyo__1sncCi_mkZlnZk1lpMbS0Ko6gldf3d0A0WKzvsoV5h4__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.css" media="all" /> <link type="text/css" rel="stylesheet" href="//cdn.jsdelivr.net/qtip2/2.2.1/jquery.qtip.min.css" media="all" /> <link type="text/css" rel="stylesheet" href="https://www.bmj.com/sites/default/files/advagg_css/css__K-qfO7iI4V_lwcmeBrmTB_sZxM1pxxWTK2hPw7F20iY__nGvxGXsd-EWhbiXQOCcRsTI7aW5EzLwnobIGD78S7u0__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.css" media="all" /> <link type="text/css" rel="stylesheet" href="https://www.bmj.com/sites/default/files/advagg_css/css__hcEfBsSfdZ2na-rT9Jhk7K2mHyy5KBdPKm6ia_F7MYU__4716zpuGoj4DfVIEENbeOWgAOX_pf_t16EI4fvJGo7A__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.css" media="print" /> <link type="text/css" rel="stylesheet" href="https://www.bmj.com/sites/default/files/advagg_css/css__b-tWEqg3_twqP_ufdNXyA5V14StJgBdiIxG1UIi0LYc__3z5eyFP7TvyPE6DkwNj3xM94b3mZNfr4lSWEChDxsvU__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.css" media="screen" /> <link type="text/css" rel="stylesheet" href="https://www.bmj.com/sites/default/files/advagg_css/css__-BkZ71IF4pBXmZfP4vYyswWdIhuaKktrUUQ4i2vtUVo__0i_0YcYkMECNn0z7FdhNoJ8gLWleqnTtjnHRAmLijvc__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.css" media="all" /> <link href="/sites/default/themes/bmj/the_bmj/css/fonts.css" rel="stylesheet" media="all" type="text/css"> <style media="screen" type="text/css"> .page-news #latest-blogs h2.pane-title, .bootstrap-threecol-4-4-4 #latest-blogs h2.pane-title { width: 153px !important; } #navigation-wrapper #navigation .main-navigation .menu.nav>li.last { display: block !important; } </style>  <script src="https://cdn.cookielaw.org/consent/tcf.stub.js"" type="text/javascript" charset="UTF-8"></script>  <script src="https://cookie-cdn.cookiepro.com/scripttemplates/otSDKStub.js" type="text/javascript" charset="UTF-8" data-domain-script="565e50dd-f6e9-46d6-91cd-5c40a270264f"></script> <script type="text/javascript"> function OnetrustAdsConsent(){ if(googletag.apiReady){ //console.log("GoogleTag API ready") googletag.pubads().disableInitialLoad(); if(OptanonActiveGroups.match(/,4,/)){ googletag.pubads().setRequestNonPersonalizedAds(0); //googletag.pubads().refresh(); } else{ googletag.pubads().setRequestNonPersonalizedAds(1); // googletag.pubads().refresh(); } } else{ OnetrustAdsConsent(); } } function OptanonWrapper() { OnetrustAdsConsent(); } </script>  <script src="https://www.bmj.com/sites/default/files/advagg_js/js__wQYYWLUWErxls_q7a6fk-aoyATq9qiA4xZWj_nuQWIY__idPe4msTM3VewG9y-TVQn9f3_mIGnqFi2cuHIkTOFDs__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.js"></script> <script src="//cdn.jsdelivr.net/qtip2/2.2.1/jquery.qtip.min.js"></script> <script src="https://www.bmj.com/sites/default/files/advagg_js/js__2vHhrvalnn5UCugvFF1gWpr2A4QMzFAF3XLwnua1Rzs__Xw__BrTMshnXhn48_6OAS9TznNeJuxDsDFLFTEPB2oQ__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.js"></script> <script src="https://www.google.com/recaptcha/api.js?hl=en&render=explicit&onload=drupalRecaptchaOnload"></script> <script src="https://www.bmj.com/sites/default/files/advagg_js/js__KRItDHdFNWCWGh10fG2AsZj0k6MqLpTrUHmgPnkfuSQ__q9D70vJTrTKWmwCWHdcjG7N3DOgFtY1GGLakOPzym6Q__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.js"></script> <script src="https://www.bmj.com/sites/default/files/advagg_js/js__UUwMbpErCBHAQQqH_Cxzi20oSmMoxcbKeYV6qoD70qc__skFUSUohWkyaYdPjJ2LSEF0xKVUuQTqmOxG-9og_468__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.js"></script> <script src="https://www.bmj.com/sites/default/files/advagg_js/js__7tN13Z_jEtWpAlHc4vWZWrFePCNhuslRS59mkCehpG8__hIhm4v2jj35Ek3jyTBAduhmH_HOFYDYH-VH1JBUELWg__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.js"></script> <script>var _prum=[['id', '612e3f1b1733500011000061'], ['mark', 'firstbyte', (new Date()).getTime()]]; (function() { var s=document.getElementsByTagName('script')[0], p=document.createElement('script'); p.async='async'; p.src='//rum-static.pingdom.net/prum.min.js';s.parentNode.insertBefore(p,s);})();</script> <script>if(typeof window.MathJax === "undefined") window.MathJax = { menuSettings: { zoom: "Click" } };</script> <script async="async" src="https://scholar.google.com/scholar_js/casa.js"></script> <script>jQuery.extend(Drupal.settings,{"basePath":"\/","pathPrefix":"","ajaxPageState":{"theme":"the_bmj","theme_token":"vmb8XEQ5OK6km1DsJw7g5UFS31Ik9PrUz-H4ZKB9_9M"},"colorbox":{"opacity":"0.85","current":"{current} of {total}","previous":"\u00ab Prev","next":"Next \u00bb","close":"Close","maxWidth":"98%","maxHeight":"98%","fixed":true,"mobiledetect":true,"mobiledevicewidth":"480px"},"highwire":{"nid":"522410","apath":"\/bmj\/314\/7074\/112.atom","pisa":"bmj;314\/7074\/112","ac":{"\/bmj\/314\/7074\/112.atom":{"access":{"full":true,"reprint":true},"pisa_id":"","apath":"\/bmj\/314\/7074\/112.atom","jcode":"bmj"},"bmj;314\/7074\/112":{"access":{"full":true},"pisa_id":"bmj;314\/7074\/112","apath":"","jcode":"bmj"}},"processed":["highwire_math"],"markup":[{"requested":"long","variant":"full-text","view":"full","pisa":"bmj;314\/7074\/112"}],"trendmd":{"trendmd-suggestions":"{\u0022element\u0022:\u0022#trendmd-suggestions\u0022,\u0022track_id\u0022:\u002224814\u0022}"},"dataLayer":"{\u0022page\u0022:{\u0022hwTitle\u0022:\u0022Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies\u0022,\u0022hwUrl\u0022:\u0022https:\\\/\\\/www.bmj.com\\\/content\\\/314\\\/7074\\\/112\u0022,\u0022hwPath\u0022:\u0022\\\/content\\\/314\\\/7074\\\/112\u0022,\u0022hwType\u0022:\u0022journal page\u0022},\u0022user\u0022:{\u0022hwMemberID\u0022:\u0022\u0022,\u0022hwLoggedIntoInstitutionID\u0022:\u0022\u0022,\u0022hwLoggedIntoInstitution\u0022:\u0022\u0022,\u0022hwAccessUsageTerms\u0022:\u0022guest\u0022,\u0022hwRegisteredUser\u0022:\u0022no\u0022,\u0022hwHasFullTextAccess\u0022:\u0022yes\u0022,\u0022hwEntitled\u0022:\u0022no\u0022,\u0022mail\u0022:\u0022e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855\u0022},\u0022content\u0022:{\u0022hwIssueDate\u0022:\u00221997-01-11\u0022,\u0022hwIssueDateTime\u0022:\u00221997-01-11 08:00:00\u0022,\u0022hwPublicationDate\u0022:\u00221997-01-11\u0022,\u0022hwPublicationDateTime\u0022:\u00221997-01-11 08:00:00\u0022,\u0022hwNlmArticleType\u0022:\u0022research-article\u0022,\u0022hwDOI\u0022:\u002210.1136\\\/bmj.314.7074.112\u0022,\u0022hwAuthors\u0022:\u0022Robert Clarke,Chris Frost,Rory Collins,Paul Appleby,Richard Peto\u0022,\u0022hwContributors\u0022:\u0022\u0022,\u0022hwIsEarlyRelease\u0022:\u0022no\u0022,\u0022hwEissn\u0022:\u00221468-5833\u0022,\u0022hwPissn\u0022:\u00220959-8138\u0022,\u0022hwVolume\u0022:\u0022314\u0022,\u0022hwIssue\u0022:\u00227074\u0022,\u0022hwArticleType\u0022:\u0022Paper\u0022,\u0022hwTabView\u0022:\u0022main_tab\u0022,\u0022hwViewType\u0022:\u0022full\u0022,\u0022hwAccessType\u0022:\u0022Free\u0022,\u0022hwOpenAccess\u0022:\u0022no\u0022,\u0022hwFreeAccess\u0022:\u0022yes\u0022,\u0022hwTaxonomy\u0022:\u0022Diet\u0022,\u0022hwCorpusCode\u0022:\u0022bmj\u0022,\u0022hwType\u0022:\u0022article\u0022,\u0022hwSubtitle\u0022:null,\u0022hwOverline\u0022:null,\u0022hwPisaId\u0022:\u0022bmj;314\\\/7074\\\/112\u0022,\u0022hwFirstPage\u0022:\u0022112\u0022,\u0022hwLastPage\u0022:null,\u0022hwIsLatestVersion\u0022:\u0022yes\u0022,\u0022hwIsCurrentIssue\u0022:\u0022no\u0022,\u0022hwIsOpenIssue\u0022:\u0022no\u0022,\u0022hwHasFullText\u0022:\u0022yes\u0022,\u0022hwHasPDF\u0022:\u0022yes\u0022,\u0022hwParentTitle\u0022:\u0022BMJ: 314 (7074)\u0022,\u0022hwElectronicPubDate\u0022:\u00221997-01-11\u0022,\u0022hwElectronicPubDateTime\u0022:\u00221997-01-11 08:00:00\u0022}}"},"jnl_bmj_infographic":{"infographic_tab":false},"custom_search":{"form_target":"_self","solr":1},"panel_ajax_tab":{"path":"sites\/all\/modules\/contrib\/panels_ajax_tab"},"instances":"{\u0022highwire_abstract_tooltip\u0022:{\u0022content\u0022:{\u0022text\u0022:\u0022\u0022},\u0022style\u0022:{\u0022tip\u0022:{\u0022width\u0022:20,\u0022height\u0022:20,\u0022border\u0022:1,\u0022offset\u0022:0,\u0022corner\u0022:true},\u0022classes\u0022:\u0022qtip-custom hw-tooltip hw-abstract-tooltip qtip-shadow qtip-rounded\u0022,\u0022classes_custom\u0022:\u0022hw-tooltip hw-abstract-tooltip\u0022},\u0022position\u0022:{\u0022at\u0022:\u0022right center\u0022,\u0022my\u0022:\u0022left center\u0022,\u0022viewport\u0022:true,\u0022adjust\u0022:{\u0022method\u0022:\u0022shift\u0022}},\u0022show\u0022:{\u0022event\u0022:\u0022mouseenter click \u0022,\u0022solo\u0022:true},\u0022hide\u0022:{\u0022event\u0022:\u0022mouseleave \u0022,\u0022fixed\u0022:1,\u0022delay\u0022:\u0022100\u0022}},\u0022highwire_author_tooltip\u0022:{\u0022content\u0022:{\u0022text\u0022:\u0022\u0022},\u0022style\u0022:{\u0022tip\u0022:{\u0022width\u0022:15,\u0022height\u0022:15,\u0022border\u0022:1,\u0022offset\u0022:0,\u0022corner\u0022:true},\u0022classes\u0022:\u0022qtip-custom hw-tooltip hw-author-tooltip qtip-shadow qtip-rounded\u0022,\u0022classes_custom\u0022:\u0022hw-tooltip hw-author-tooltip\u0022},\u0022position\u0022:{\u0022at\u0022:\u0022top center\u0022,\u0022my\u0022:\u0022bottom center\u0022,\u0022viewport\u0022:true,\u0022adjust\u0022:{\u0022method\u0022:\u0022\u0022}},\u0022show\u0022:{\u0022event\u0022:\u0022mouseenter \u0022,\u0022solo\u0022:true},\u0022hide\u0022:{\u0022event\u0022:\u0022mouseleave \u0022,\u0022fixed\u0022:1,\u0022delay\u0022:\u0022100\u0022}},\u0022highwire_reflinks_tooltip\u0022:{\u0022content\u0022:{\u0022text\u0022:\u0022\u0022},\u0022style\u0022:{\u0022tip\u0022:{\u0022width\u0022:15,\u0022height\u0022:15,\u0022border\u0022:1,\u0022mimic\u0022:\u0022top center\u0022,\u0022offset\u0022:0,\u0022corner\u0022:true},\u0022classes\u0022:\u0022qtip-custom hw-tooltip hw-ref-link-tooltip qtip-shadow qtip-rounded\u0022,\u0022classes_custom\u0022:\u0022hw-tooltip hw-ref-link-tooltip\u0022},\u0022position\u0022:{\u0022at\u0022:\u0022bottom left\u0022,\u0022my\u0022:\u0022top left\u0022,\u0022viewport\u0022:true,\u0022adjust\u0022:{\u0022method\u0022:\u0022flip\u0022}},\u0022show\u0022:{\u0022event\u0022:\u0022mouseenter \u0022,\u0022solo\u0022:true},\u0022hide\u0022:{\u0022event\u0022:\u0022mouseleave \u0022,\u0022fixed\u0022:1,\u0022delay\u0022:\u0022100\u0022}}}","qtipDebug":"{\u0022leaveElement\u0022:0}","ws_fl":{"width":100,"height":21},"jnl_bmj":{"container_id_share":"article-share-modal","container_id_response":"article-response-modal"},"urlIsAjaxTrusted":{"\/content\/314\/7074\/112?tab=article-alert":true,"\/content\/314\/7074\/112":true,"\/login":true},"orcidLogo":{"svg":"\/sites\/default\/themes\/bmj\/the_bmj\/img\/vector_iD_icon.svg"},"bootstrap":{"anchorsFix":"1","anchorsSmoothScrolling":"1","popoverEnabled":"1","popoverOptions":{"animation":1,"html":0,"placement":"right","selector":"","trigger":"click","title":"","content":"","delay":0,"container":"body"},"tooltipEnabled":"1","tooltipOptions":{"animation":1,"html":0,"placement":"auto left","selector":"","trigger":"hover focus","delay":0,"container":"body"}}});</script> <script type="text/javascript"> window.dataLayer = window.dataLayer || []; </script>  <script type="text/javascript">var DC = { Date : "", subject : "" };var ga_article_category = "Paper";var ga_article_page_type = "research-article";var ga_article_pub_year = "1997";var ga_customer_number = "";var ga_user_type = "";DC.Date = "1997-01-11";DC.subject = "";</script>   <style>.async-hide { opacity: 0 !important} </style> <script>(function(a,s,y,n,c,h,i,d,e){s.className+=' '+y;h.start=1*new Date; h.end=i=function(){s.className=s.className.replace(RegExp(' ?'+y),'')}; (a[n]=a[n]||[]).hide=h;setTimeout(function(){i();h.end=null},c);h.timeout=c;})(window,document.documentElement,'async-hide','dataLayer',4000,{'GTM-NF7HCLL':true});</script>   <script>var googletag = window.googletag || {cmd: []};</script> <script async src="//securepubads.g.doubleclick.net/tag/js/gpt.js"></script> <script> var topBottomSizes = [ [970,250],[970,90],[728,90],[468,60],[300,50],[320,100] ]; var mpuSizes = [ [300,250],[300,600],[600,600], ]; //googletag.cmd.push(function() { googletag.display('div-gpt-ad-7326006-1'); }); googletag.cmd.push(function() { googletag.defineSlot('/21798771943/BMJ.com_HomePage_TOPBanner', topBottomSizes,'div-gpt-ad-7326006-1').addService(googletag.pubads()).setTargeting("pgid", "pubgrade_lib_disabled"); googletag.defineSlot('/21798771943/BMJ.com_HomePage_MPU1', mpuSizes, 'div-gpt-ad-7326006-2').addService(googletag.pubads()); googletag.defineSlot('/21798771943/BMJ.com_HomePage_MPU2', mpuSizes, 'div-gpt-ad-7326006-3').addService(googletag.pubads()); googletag.defineSlot('/21798771943/BMJ.com_HomePage_BOTTOM', topBottomSizes, 'div-gpt-ad-7326006-4').addService(googletag.pubads()); googletag.pubads().setTargeting('url', window.parent.location.pathname); // Some examples of ways to enable below. Normally, only one of these // methods should be used. // A) Enable with defaults. googletag.pubads().enableLazyLoad({ fetchMarginPercent: 0, // Fetch slots within 1 viewports. renderMarginPercent: 0, // Render slots within 1 viewports. mobileScaling: 2.0 // Double the above values on mobile. }); googletag.enableServices(); }); </script> <script> let cookies = parseCookies(); let bmj_uuid = cookies.bmj_uuid; let bmj_ppid = cookies.bmj_ppid; window.dataLayer = window.dataLayer || []; function checkUserLoginStatus(dataLayer) { const userMail = dataLayer.find((item) => item.user)?.user?.mail; if (!userMail) { return false; } return userMail !== anonMailId; } const anonMailId = 'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855'; let nonAnonMailId = ((dataLayer.find(item => item.user)?.user)?.mail) === anonMailId ? null : (dataLayer.find(item => item.user)?.user)?.mail; let userId = ((dataLayer.find(item => item.user)?.user)?.['data-ics']) ?? ((dataLayer.find(item => item.user)?.user)?.mail && nonAnonMailId) ?? bmj_ppid ?? bmj_uuid; document.cookie = 'bmj_ppid=' + userId + '; domain=.bmj.com; path=/; max-age=31622400; SameSite=None; Secure'; googletag.cmd.push(function() { googletag.pubads().setPublisherProvidedId(userId); googletag.pubads().setTargeting("islogged", checkUserLoginStatus(dataLayer) ? "true" : "false"); googletag.enableServices(); }); window.dataLayer.push({ 'bmj_uuid': bmj_uuid }); </script> </head>   <script type="text/javascript">(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0];var j=d.createElement(s);var dl=l!='dataLayer'?'&l='+l:'';j.src='//www.googletagmanager.com/gtm.js?id='+i+dl;j.type='text/javascript';j.async=true;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-NF7HCLL');</script>  </head>  <body class="html not-front not-logged-in no-sidebars page-node page-node- page-node-522410 node-type-highwire-article 1 Paper" >  <noscript><iframe src="//www.googletagmanager.com/ns.html?id=GTM-NF7HCLL" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>  <div id="skip-link"> <a href="#main-content" class="element-invisible element-focusable">Skip to main content</a> </div> <div id="wrapper-outer"> <div id="wrapper"> <header> <div class="bmj-disclaimer"> <p>Intended for healthcare professionals</p> </div> <div class="ad-leaderboard"> <div id='div-gpt-ad-7326006-1'> <script> googletag.cmd.push(function() { googletag.display('div-gpt-ad-7326006-1'); }); </script> </div> </div>   <div id="top-nav" role="navigation" class="navbar navbar-static-top"> <div class="container"> <div id="userbar-status"> <ul id="status"> <li class="user-status-link user-status-subscribe phone-menu-item"> <a href="/us/subscribe">Subscribe</a> </li> <li class="user-status-myaccount phone-menu-item"> <div class="btn-group has-submenu"> <a class="btn dropdown-toggle" aria-expanded="false" aria-haspopup="true" data-toggle="dropdown" href="#" > My Account <span class="caret" aria-expanded="true"></span> </a> <ul class="jnl-bmj-user-my-account dropdown-menu"><li class="0 first last"><a href="//myaccount.bmj.com/myaccount/account/hw-registration.html">My email alerts</a></li> </ul></div> </li> <li class="user-status-bma phone-menu-item"> <a href="//bmjverification.bma.org.uk/validate/userdetails?url=https://www.bmj.com/content/314/7074/112?sso=">BMA member login</a> </li> <div class="btn-group has-submenu"> <a class="btn dropdown-toggle" aria-expanded="false" aria-haspopup="true" data-toggle="dropdown" href="#" > Login <span class="caret" aria-expanded="true"></span> </a> <ul class="jnl-bmj-user-signin-popup dropdown-menu"><li class="0 first last"><span><form action="/login" method="post" id="jnl-bmj-user-login-form" accept-charset="UTF-8"><div><input type="hidden" name="form_build_id" value="form-PYgbd3zm70eOp8-fz9OMh7YNUK5TnlatBz0GUNUq2Lo" /> <input type="hidden" name="form_id" value="jnl_bmj_user_login_form" /> <div class="form-type-textfield form-item-name form-item form-group"> <label for="article-p-name">Username <span class="form-required" title="This field is required.">*</span></label> <input class="form-control form-text required" type="text" id="article-p-name" name="name" value="" size="15" maxlength="60" /> </div> <div class="form-type-password form-item-pass form-item form-group"> <label for="article-p-pass">Password <span class="form-required" title="This field is required.">*</span></label> <input class="form-control form-text required" type="password" id="article-p-pass" name="pass" size="15" maxlength="128" /> </div> <div class="link"><div id="edit-forgot" class="form-type-item form-item form-group"> <label for="edit-forgot"><a href="https://www.bmj.com/user/password" title="Retrieve your credentials.">Forgot your log in details?</a> </label> </div> </div><div class="link"><div id="edit-activate" class="form-type-item form-item form-group"> <label for="edit-activate"><a href="//journals.bmj.com/cgi/activate/basic">Need to activate</a> </label> </div> </div><input class="btn form-submit" type="submit" id="edit-submit--8" name="op" value="Login" /><div id="edit-message" class="form-type-item form-item form-group"> </div> <hr /><div id="edit-bma-members" class="form-type-item form-item form-group"> <label for="edit-bma-members"><a href="//bmjverification.bma.org.uk/validate/userdetails?url=https%3A//www.bmj.com/content/314/7074/112%3Fsso%3D" title="Log in here if you are a BMA member.">BMA Member Log In</a> </label> </div> <div id="edit-athens" class="form-type-item form-item form-group"> <label for="edit-athens"><a href="https://openathens-sp.highwire.org/session/init?entityID=https%3A//idp.eduserv.org.uk/openathens&subcode=bmjjournals&hw-shib-return-uri=https%253A%252F%252Fwww.bmj.com%252Fcontent%252F314%252F7074%252F112">Log in via OpenAthens</a> </label> </div> <div id="edit-shibboleth" class="form-type-item form-item form-group"> <label for="edit-shibboleth"><a href="/login/shibboleth?uri=https%3A%2F%2Fwww.bmj.com%2Fcontent%2F314%2F7074%2F112&subcode=bmjjournals&env=prod">Log in via your institution</a> </label> </div> </div></form></span></li> </ul></div> </ul> <div id="userbar"> <div class="region region-userbar"> <section id="block-panels-mini-jnl-bmj-country-portal-switcher" class="block block-panels-mini clearfix"> <div class="panel-display panel-1col clearfix" id="mini-panel-jnl_bmj_country_portal_switcher"> <div class="panel-panel panel-col"> <div><div class="panel-pane pane-country-switcher" > <div class="pane-content"> <span class="country-label">Edition: </span> <div class="btn-group has-submenu"> <a class="btn dropdown-toggle" aria-expanded="false" aria-haspopup="true" data-toggle="dropdown" href="#" id=country-switcher> US <span class="caret" aria-expanded="true"></span> </a> <ul class="jnl-bmj-country-portal-country-switcher dropdown-menu"><li class="0 first"><a href="/bmj_countries/switch/uk?destination=node/522410">UK</a></li> <li class="1"><a href="/bmj_countries/switch/india?destination=node/522410">South Asia</a></li> <li class="2 last"><a href="/bmj_countries/switch/international?destination=node/522410">International</a></li> </ul></div> </div> </div> </div> </div> </div> </section>  </div> </div> <div id="cmp-link"> <div class="pane-content"> <span class="country-label"><a href="/company?int_source=tbmj&int_medium=header&int_campaign=URLswitch">Our company</a></span> </div> </div> </div> </div> </div>  <div id="main-nav" data-spy="affix" data-offset-top="125"> <div class="primary-navigation-bar"> <div id="navigation-wrapper"> <div class="container">  <a href="#" id="btn-nav" class=""> <span class="sr-only">Toggle navigation</span> </a>  <a class="logo navbar-btn pull-left" href="/" title="Home">  <div class="bmj-logo">The BMJ logo</div> </a> <div class="ie6-site-map"><a href="/sitemap">Site map</a></div>  <div class="main-nav-search"> <div id="search">  <a href="#" class="dropdown-toggle" data-toggle="dropdown" title="Search"><div class="search"><em class="fa fa-search" alt="Search"></em><span class="search-label">Search</span></div></a> <div class="dropdown-menu"> <div class="header-search-form container"> <div class="searchbar"> <div class="region region-search-block"> <section id="block-search-form" class="block block-search clearfix"> <form class="search-form form-search content-search" action="/content/314/7074/112" method="post" id="search-block-form" accept-charset="UTF-8"><div><div> <h2 class="element-invisible">Search form</h2> <div class="input-group"><input title="Enter the terms you wish to search for." class="container-inline input-append form-control form-text" placeholder="Search The BMJ" type="text" id="edit-search-block-form--2" name="search_block_form" value="" size="15" maxlength="128" /><span class="input-group-btn"><button type="submit" class="btn btn-default">Search</button></span></div><button class="element-invisible btn btn-primary btn btn-primary form-button" type="submit" id="edit-submit--3" name="op" value="Search">Search</button><input type="hidden" name="form_build_id" value="form-w421KvvyOrZU_fiuvzyPXO1vwfQ1KVZfTmeRJUrewco" /> <input type="hidden" name="form_id" value="search_block_form" /> <input type="hidden" name="custom_search_paths" value="search/advanced/[key]" /> </div> </div></form> </section>  </div> </div> <div class="advanced-search"> <ul class="list-inline"> <li><a href="/search/advanced" title="Advanced search">Advanced search</a></li> <li><a href="/rapid-responses" title="Search responses">Search responses</a></li> <li><a href="//blogs.bmj.com/bmj/" title="Search blogs">Search blogs</a></li> </ul> </div> </div> </div> </div> </div>  <a href="#" id="toggle-mobile-top-nav"> <span class="fa fa-cog"></span> <span class="sr-only">Toggle top menu</span> </a>  <div id="navigation" class="navigation">  <div class="main-navigation"> <nav role="navigation"> <ul class="menu nav navbar-nav"><li class="first leaf"><a href="/coronavirus">covid-19</a></li> <li class="expanded dropdown"><a href="/us/research" data-target="#" class="dropdown-toggle" data-toggle="dropdown">Research</a><ul class="dropdown-menu"><li class="first leaf"><a href="/us/research">At a glance</a></li> <li class="leaf"><a href="/us/research/research">Research papers</a></li> <li class="leaf"><a href="/us/research/research%20methods%20%26amp%3B%20reporting">Research methods and reporting</a></li> <li class="last leaf"><a href="/us/research/minerva">Minerva</a></li> </ul></li> <li class="expanded dropdown"><a href="/us/education" data-target="#" class="dropdown-toggle" data-toggle="dropdown">Education</a><ul class="dropdown-menu"><li class="first leaf"><a href="/us/education">At a glance</a></li> <li class="leaf"><a href="/us/education/clinical%20review">Clinical reviews</a></li> <li class="leaf"><a href="/us/education/practice">Practice</a></li> <li class="leaf"><a href="/us/education/minerva">Minerva</a></li> <li class="leaf"><a href="/us/education/endgames">Endgames</a></li> <li class="leaf"><a href="/specialties/state-art">State of the art</a></li> <li class="leaf"><a href="/specialties/what-your-patient-thinking">What your patient is thinking</a></li> <li class="leaf"><a href="/rapid-recommendations">Rapid recommendations</a></li> <li class="last leaf"><a href="/student">Student</a></li> </ul></li> <li class="expanded dropdown"><a href="/us/news" data-target="#" class="dropdown-toggle" data-toggle="dropdown">News & Views</a><ul class="dropdown-menu"><li class="first leaf"><a href="/us/news">At a glance</a></li> <li class="leaf"><a href="/us/news/news?category=News">News</a></li> <li class="leaf"><a href="/us/news/feature">Features</a></li> <li class="leaf"><a href="/us/news/editorial">Editorials</a></li> <li class="leaf"><a href="/us/news/analysis">Analysis</a></li> <li class="leaf"><a href="/news/opinion">Opinion</a></li> <li class="leaf"><a href="/us/news/head%20to%20head">Head to head</a></li> <li class="leaf"><a href="/us/news/editor%27s%20choice">Editor's choice</a></li> <li class="leaf"><a href="/us/news/letter">Letters</a></li> <li class="leaf"><a href="/us/news/obituary">Obituaries</a></li> <li class="leaf"><a href="/careers-articles">Careers</a></li> <li class="last leaf"><a href="/rapid-responses">Rapid responses</a></li> </ul></li> <li class="expanded dropdown"><a href="/campaigns" data-target="#" class="dropdown-toggle" data-toggle="dropdown">Campaigns</a><ul class="dropdown-menu"><li class="first leaf"><a href="/campaigns">At a glance</a></li> <li class="leaf"><a href="/better-evidence">Better evidence</a></li> <li class="leaf"><a href="/campaign/climate-emergency">Climate change</a></li> <li class="leaf"><a href="/divestment">Divestment from fossil fuels</a></li> <li class="leaf"><a href="/campaign/patient-partnership">Patient and public partnership</a></li> <li class="last leaf"><a href="/too-much-medicine">Too much medicine</a></li> </ul></li> <li class="last expanded dropdown"><a href="/careers" data-target="#" class="dropdown-toggle" data-toggle="dropdown">Jobs</a><ul class="dropdown-menu"><li class="first leaf"><a href="/careers">Doctor Jobs UK</a></li> <li class="leaf"><a href="/careers/jobs/hospital/">Hospital Jobs UK</a></li> <li class="leaf"><a href="/careers/jobs/general-practice/">GP Jobs UK</a></li> <li class="last leaf"><a href="/careers/jobs/international/">International Jobs</a></li> </ul></li> </ul>  <div class="second-navigation"> <ul class="secondary-nav" id=""> <li class="even"><a href="/archive" class="">Archive</a></li> <li class="odd"><a href="/about-bmj/resources-authors" class="">For authors</a></li> <li class="odd last"><a href="http://hosted.bmj.com" class="">Hosted</a></li> </ul> </div> </nav> </div> </div> </div> </div> </div> </div> </header> <div class="main-container container" id="page">   <div class="row"> <section class="col-sm-12" > <ol class="breadcrumb"><li class="first"><a href="/us/research">Research</a></li> <li>Dietary lipids and...</li> <li class="active last">Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies</li> </ol> <a id="main-content"></a> <div class="region region-content"> <section id="block-system-main" class="block block-system clearfix"> <div class="panel-display" > <div class="hero"> <div class="hero-wrapper"> <div class="hero-content" style="position: relative; left: 0px; top: 35.5px;"> </div>  </div>  </div>  <div class="row"> <div class="left-content col-xs-12 col-sm-8 col-md-8 col-lg-8"> <article> <div class="panel-pane pane-highwire-article-citation" > <div class="pane-content"> <div class="highwire-article-citation highwire-citation-type-highwire-article node522410" data-node-nid="522410" id="node-522410--22098006620" data-pisa="bmj;314/7074/112" data-pisa-master="bmj;314/7074/112" data-apath="/bmj/314/7074/112.atom"><cite class='highwire-cite highwire-citation-bmj-article-top'> <span class='highwire-cite-article-type'>Papers</span> <h1 class="highwire-cite-title" id="page-title">Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies</h1> <span class='highwire-cite-journal'>BMJ</span> <span class='highwire-cite-published-year'>1997</span>; <span class='highwire-cite-volume-issue'>314</span> <span class='highwire-cite-doi'> doi: <a href="https://doi.org/10.1136/bmj.314.7074.112">https://doi.org/10.1136/bmj.314.7074.112</a></span> <span class='highwire-cite-date'>(Published 11 January 1997)</span> <span class='highwire-cite-article-as'> Cite this as: <span class="italic">BMJ</span> 1997;314:112 </span> </cite> </div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-highwire-panel-tabs pane-panels-ajax-tab-tabs" > <div class="pane-content"> <ul class="tabs inline panels-ajax-tab"><li class="first"><a title="Article Tab - Article" href="/content/314/7074/112" class="panels-ajax-tab-tab" data-panel-name="jnl_bmj_tab_art" data-target-id="highwire_article_tabs" data-entity-context="node:522410" data-trigger="" data-url-enabled="1"><span>Article</span></a><a title="Article Tab - Article" href="/panels_ajax_tab/jnl_bmj_tab_art/node:522410/1" rel="nofollow" style="display:none" class="js-crawler-link"></a></li> <li><a title="Article Tab - Related Articles" href="/content/314/7074/112/related" class="panels-ajax-tab-tab" data-panel-name="jnl_bmj_tab_related_art" data-target-id="highwire_article_tabs" data-entity-context="node:522410" data-trigger="related" data-url-enabled="1"><span>Related content</span></a><a title="Article Tab - Related Articles" href="/panels_ajax_tab/jnl_bmj_tab_related_art/node:522410/1" rel="nofollow" style="display:none" class="js-crawler-link"></a></li> <li><a title="Article Tab - Info & Metrics" href="/content/314/7074/112/article-info" class="panels-ajax-tab-tab" data-panel-name="jnl_bmj_tab_info" data-target-id="highwire_article_tabs" data-entity-context="node:522410" data-trigger="article-info" data-url-enabled="1"><span>Metrics</span></a><a title="Article Tab - Info & Metrics" href="/panels_ajax_tab/jnl_bmj_tab_info/node:522410/1" rel="nofollow" style="display:none" class="js-crawler-link"></a></li> <li><a title="BMJ Article Related Rapid Responses" href="/content/314/7074/112/rapid-responses" class="panels-ajax-tab-tab" data-panel-name="bmj_related_rapid_responses" data-target-id="highwire_article_tabs" data-entity-context="node:522410" data-trigger="rapid-responses" data-url-enabled="1"><span>Responses</span></a><a title="BMJ Article Related Rapid Responses" href="/panels_ajax_tab/bmj_related_rapid_responses/node:522410/1" rel="nofollow" style="display:none" class="js-crawler-link"></a></li> <li><a title="Article Tab - Peer review" href="/content/314/7074/112/peer-review" class="panels-ajax-tab-tab" data-panel-name="jnl_bmj_tab_peer_review" data-target-id="highwire_article_tabs" data-entity-context="node:522410" data-trigger="peer-review" data-url-enabled="1"><span>Peer review</span></a><a title="Article Tab - Peer review" href="/panels_ajax_tab/jnl_bmj_tab_peer_review/node:522410/1" rel="nofollow" style="display:none" class="js-crawler-link"></a></li> <li class="last"><a title="BMJ Rapid Responses Form" href="/content/314/7074/112/submit-a-rapid-response" class="panels-ajax-tab-tab" data-panel-name="bmj_rapid_responses_form" data-target-id="highwire_article_tabs" data-entity-context="node:522410" data-trigger="submit-a-rapid-response" data-url-enabled="1"><i class="fa fa-edit"></i></a><a title="BMJ Rapid Responses Form" href="/panels_ajax_tab/bmj_rapid_responses_form/node:522410/1" rel="nofollow" style="display:none" class="js-crawler-link"></a></li> </ul> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-highwire-panel-tabs-container" > <div class="pane-content"> <div data-panels-ajax-tab-preloaded="jnl_bmj_tab_art" id="panels-ajax-tab-container-highwire_article_tabs" class="panels-ajax-tab-container"><div class="panels-ajax-tab-loading" style ="display:none"><img class="loading" src="https://www.bmj.com/sites/all/modules/contrib/panels_ajax_tab/images/loading.gif" alt="Loading" title="Loading" /></div><div class="panels-ajax-tab-wrap-jnl_bmj_tab_art"><div class="panel-display panel-1col clearfix" > <div class="panel-panel panel-col"> <div><div class="panel-pane pane-highwire-markup" > <div class="pane-content"> <div class="highwire-markup"><div xmlns="http://www.w3.org/1999/xhtml" data-highwire-cite-ref-tooltip-instance="highwire_reflinks_tooltip" class="content-block-markup" xmlns:xhtml="http://www.w3.org/1999/xhtml"><div class="article fulltext-view"><span class="highwire-journal-article-marker-start"></span><div class="contributors"><ol class="contributor-list" id="contrib-group-1"><li class="contributor" id="contrib-1"><span class="name">Robert Clarke</span><a id="xref-aff-1-1" class="xref-aff" href="#aff-1">a</a><span class="contrib-role">, research fellow</span>, </li><li class="contributor" id="contrib-2"><span class="name">Chris Frost</span><a id="xref-aff-2-1" class="xref-aff" href="#aff-2">b</a><span class="contrib-role">, lecturer</span>, </li><li class="contributor" id="contrib-3"><span class="name">Rory Collins</span><a id="xref-aff-1-2" class="xref-aff" href="#aff-1">a</a><span class="contrib-role">, professor of medicine and epidemiology</span>, </li><li class="contributor" id="contrib-4"><span class="name">Paul Appleby</span><a id="xref-aff-1-3" class="xref-aff" href="#aff-1">a</a><span class="contrib-role">, research officer</span>, </li><li class="last" id="contrib-5"><span class="name">Richard Peto</span><a id="xref-aff-1-4" class="xref-aff" href="#aff-1">a</a><span class="contrib-role">, professor of medical statistics and epidemiology</span></li></ol><ol class="affiliation-list"><li class="aff"><a id="aff-1" name="aff-1"></a><address><sup>a</sup> Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Clinical Medicine, Radcliffe Infirmary, Oxford OX2 6HE</address></li><li class="aff"><a id="aff-2" name="aff-2"></a><address><sup>b</sup> Department of Statistics, London School of Hygiene and Tropical Medicine, London WC1E 7HT</address></li></ol><ol class="corresp-list"><li class="corresp" id="corresp-1">Correspondence to: Dr Clarke</li></ol><ul class="history-list"><li xmlns:hwp="http://schema.highwire.org/Journal" class="accepted" hwp:start="1996-10-28"><span class="accepted-label">Accepted </span>28 October 1996</li></ul></div><div class="section abstract" id="abstract-1"> <h2>Abstract</h2> <p id="p-1"><strong>Objective:</strong> To determine the quantitative importance of dietary fatty acids and dietary cholesterol to blood concentrations of total, low density lipoprotein, and high density lipoprotein cholesterol.</p> <p id="p-2"><strong>Design:</strong> Meta-analysis of metabolic ward studies of solid food diets in healthy volunteers.</p> <p id="p-3"><strong>Subjects:</strong> 395 dietary experiments (median duration 1 month) among 129 groups of individuals.</p> <p id="p-4"><strong>Results:</strong> Isocaloric replacement of saturated fats by complex carbohydrates for 10% of dietary calories resulted in blood total cholesterol falling by 0.52 (SE 0.03) mmol/l and low density lipoprotein cholesterol falling by 0.36 (0.05) mmol/l. Isocaloric replacement of complex carbohydrates by polyunsaturated fats for 5% of dietary calories resulted in total cholesterol falling by a further 0.13 (0.02) mmol/l and low density lipoprotein cholesterol falling by 0.11 (0.02) mmol/l. Similar replacement of carbohydrates by monounsaturated fats produced no significant effect on total or low density lipoprotein cholesterol. Avoiding 200 mg/day dietary cholesterol further decreased blood total cholesterol by 0.13 (0.02) mmol/l and low density lipoprotein cholesterol by 0.10 (0.02) mmol/l.</p> <p id="p-5"><strong>Conclusions:</strong> In typical British diets replacing 60% of saturated fats by other fats and avoiding 60% of dietary cholesterol would reduce blood total cholesterol by about 0.8 mmol/l (that is, by 10-15%), with four fifths of this reduction being in low density lipoprotein cholesterol.</p> <p id="p-6"><div class="boxed-text" id="boxed-text-1"> <div id="sec-1" class="subsection"> <h4>Key messages</h4> <ul class="list-unord" id="list-1"><li id="list-item-1"><p id="p-7">The quantitative importance of diet to blood cholesterol remains uncertain because non-experimental dietary studies in community subjects are unreliable and experimental (“metabolic ward”) studies have been too small to be separately reliable</p></li><li id="list-item-2"><p id="p-8">We conducted a meta-analysis of 395 published, metabolic ward experiments of the effects of various dietary lipids on blood cholesterol</p></li><li id="list-item-3"><p id="p-9">Isocaloric increases in saturated fat intake were associated with increases in total and low density lipoprotein cholesterol and smaller increases in high density lipoprotein cholesterol; increased polyunsaturated fat intake decreased total and low density lipoprotein cholesterol and increased high density lipoprotein cholesterol; monounsaturated fat had no significant effect on total and low density lipoprotein cholesterol but increased high density lipoprotein cholesterol</p></li><li id="list-item-4"><p id="p-10">In the average British diet replacement of 60% of the saturated fat by other dietary fats and avoidance of 60% of dietary cholesterol would reduce blood cholesterol by about 0.8 mmol/l (that is, by 10-15%), with four fifths of this reduction being in low density lipoprotein cholesterol</p></li><li id="list-item-5"><p id="p-11">The effect on vascular disease of a prolonged difference of 0.8 mmol/l in blood cholesterol concentration depends on the relative importance at different ages of the benefits of reducing low density lipoprotein cholesterol and the hazards of reducing high density lipoprotein cholesterol, which require further study</p></li></ul> </div> </div></p> </div><div class="section" id="sec-2"> <h2>Introduction</h2> <p id="p-12">The quantitative importance of diet to blood total cholesterol and, more importantly, to its fractions (low density lipoprotein and high density lipoprotein cholesterol), remains uncertain.<a id="xref-ref-1-1" class="xref-bibr" href="#ref-1">1</a><a id="xref-ref-2-1" class="xref-bibr" href="#ref-2">2</a><a id="xref-ref-3-1" class="xref-bibr" href="#ref-3">3</a><a id="xref-ref-4-1" class="xref-bibr" href="#ref-4">4</a><a id="xref-ref-5-1" class="xref-bibr" href="#ref-5">5</a> This is partly because metabolic mechanisms are not clear, partly because non-experimental dietary studies in community subjects are unreliable,<a id="xref-ref-6-1" class="xref-bibr" href="#ref-6">6</a><a id="xref-ref-7-1" class="xref-bibr" href="#ref-7">7</a><a id="xref-ref-8-1" class="xref-bibr" href="#ref-8">8</a><a id="xref-ref-9-1" class="xref-bibr" href="#ref-9">9</a><a id="xref-ref-10-1" class="xref-bibr" href="#ref-10">10</a><a id="xref-ref-11-1" class="xref-bibr" href="#ref-11">11</a> and partly because previous experimental (that is, “metabolic ward”) studies have been too small to be reliable. Hence, selective emphasis on particular studies can lead to conflicting conclusions about important issues<a id="xref-ref-12-1" class="xref-bibr" href="#ref-12">12</a>–for example, whether isocalorically replacing complex carbohydrates by monounsaturated fats affects blood total cholesterol or its fractions.<a id="xref-ref-13-1" class="xref-bibr" href="#ref-13">13</a><a id="xref-ref-14-1" class="xref-bibr" href="#ref-14">14</a><a id="xref-ref-15-1" class="xref-bibr" href="#ref-15">15</a><a id="xref-ref-16-1" class="xref-bibr" href="#ref-16">16</a> The aim of this meta-analysis of metabolic ward studies is to provide reliable quantitative estimates of the relevance of dietary intake of fatty acids and dietary cholesterol to blood concentrations of total cholesterol and cholesterol fractions.</p> </div><div class="section" id="sec-3"> <h2>Methods</h2> <div id="sec-4" class="subsection"> <h3>Studies included</h3> <p id="p-13">Published reports of dietary intervention studies conducted under controlled conditions that ensured compliance (metabolic ward studies) with diets persisting at least two weeks were systematically sought by Medline searches, scanning relevant reference lists, and handsearching nutrition journals. We excluded studies if they were of subjects selected for some disorder (such as diabetes or dyslipidaemia), if the dietary changes were deliberately confounded by other interventions (such as weight reduction or exercise), or if there were no data available about dietary fatty acids or dietary cholesterol. The search strategy (details of which are available on request) did not, however, require the availability of data on changes in body weight. Because the dietary changes were to be isocaloric and most experimental periods lasted only a few weeks, substantial weight changes were not expected. Hence, many relevant publications did not include data on body weight after the experimental periods (and, of those that did, many found no material differences<a id="xref-ref-17-1" class="xref-bibr" href="#ref-17">17</a> <a id="xref-ref-18-1" class="xref-bibr" href="#ref-18">18</a>).</p> <p id="p-14">Among the 81 eligible reports identified (see appendix), we excluded one long term multicentre study for poor compliance. Solid food diets were assessed in 72 of these reports among 129 groups of subjects in 395 experiments with various designs (109 randomised crossover, 57 randomised or matched parallel, 77 non-randomised Latin square, and 152 non-randomised sequential). Details of the major individual fatty acids in the diets were available for 134 experiments, and blood concentrations of high density lipoprotein and low density lipoprotein fractions of cholesterol were available for 227. Liquid formula diets, which were assessed in 32 experiments in eight reports, were examined separately because the effects of such diets may differ from those of solid food diets.<a id="xref-ref-19-1" class="xref-bibr" href="#ref-19">19</a></p> </div> <div id="sec-5" class="subsection"> <h3>Information collected</h3> <p id="p-15">From each publication, we sought information about mean age and weight, the experimental diets (caloric intake; intake of dietary cholesterol; and percentage of calories as total, saturated, polyunsaturated, and monounsaturated fat), and blood cholesterol concentrations (total, low density lipoprotein, and high density lipoprotein) in plasma or serum at the end of the experiments. For some experiments, the mean weight, age, or dietary cholesterol had to be estimated from median or mid-range values. Fatty acids were classified by carbon chain lengths (with C18, for example, indicating 18 carbons) and by the number of carbon-carbon double bonds (such as C18:1). Saturated fatty acids have no such double bonds, monounsaturates have one, and polyunsaturates have more than one. Double bonds are <em>cis</em> if the two hydrogen atoms at each end are on the same side of the double bond and <em>trans</em> if otherwise.</p> </div> <div id="sec-6" class="subsection"> <h3>Statistical methods</h3> <p id="p-16">We used “Multilevel” regression analyses (MLN-software, London University Education Institute) that included age, weight, and dietary intake of nutrients as well as one term per study to ensure that people within any one study were compared directly only with each other. Such analyses assessed different sources of variability: (<em>a</em>) within group, between experiments; (<em>b</em>) within study, between matched groups; (<em>c</em>) within study, between unmatched groups; and (<em>d</em>) between studies.</p> <div class="table pos-float" id="T1"><div class="table"><div class="table-caption"><span class="table-label">Table 1</span> <p id="p-17" class="first-child">Regression coefficients (SE) for effects of dietary fats on total blood cholesterol concentration (from 395 solid food experiments) and on low density lipoprotein and high density lipoprotein cholesterol concentrations (from 227 solid food experiments)</p><div class="sb-div caption-clear"></div></div><div class="table-inline"><div class="callout"><span>View this table:</span><ul class="callout-links"><li><a href="/highwire/markup/606384/expansion?width=1000&height=500&iframe=true&postprocessors=highwire_figures%2Chighwire_math" class="colorbox colorbox-load table-expand-popup" rel="gallery-fragment-tables">View popup</a></li><li><a href="" class="table-expand-inline" data-table-url="/highwire/markup/606384/expansion?postprocessors=highwire_figures%2Chighwire_math">View inline</a></li></ul></div></div></div><div></div></div> </div> </div><div class="section" id="sec-7"> <h2>Results</h2> <div id="sec-8" class="subsection"> <h3>Univariate and multivariate analyses for total cholesterol</h3> <p id="p-20">Figure <a id="xref-fig-1-1" class="xref-fig" href="#F1">1</a> plots the mean dietary saturated fat in each experiment against the mean blood total cholesterol concentration at its end, with separate plots for different types of experimental design with solid food diets and for liquid formula diets, but without adjustment for factors other than intake of saturated fat. Crude correlations might misrepresent the real relations as some experimental periods were part of the same study, but the multilevel regression analyses that are plotted take appropriate account of such differences. The four regression slopes for the different types of solid food experiments were similar, and so the results of these 395 experiments were combined. The overall effects of saturated fat were less in the liquid formula experiments, and so these are considered separately. Univariate regressions for the solid food experiments indicated that dietary intakes of saturated fat, cholesterol, and total fat were each associated with highly significant increases in blood total cholesterol, while intake of polyunsaturated fat was associated with a highly significant decrease and intake of monounsaturated fat produced no significant effect on blood total cholesterol (table <a id="xref-table-wrap-1-1" class="xref-table" href="#T1">1</a>).</p> <div id="F1" class="fig pos-float odd"><div class="fig-inline"><div class="highwire-figure"><div class="fig-inline-img-wrapper"><div class="fig-inline-img"><a href="https://www.bmj.com/content/bmj/314/7074/112/F1.large.jpg?width=800&height=600" title="Univariate multilevel regression slopes of blood total cholesterol v dietary saturated fat in metabolic ward experiments, by different experimental design. (The equations take account of which experiments were part of the same study; dotted lines represent a typical intake of saturated fat (15% of dietary calories), and this is used as an intercept for the regression equations; no adjustments are made for total energy intake or any other aspects of experimental diets)" class="colorbox fragment-images colorbox-load" rel="gallery-fragment-images" data-figure-caption="<div class="highwire-markup"><div class="fig-caption" xmlns:xhtml="http://www.w3.org/1999/xhtml"><span class="fig-label">FIG 1</span> <p id="p-21" class="first-child">Univariate multilevel regression slopes of blood total cholesterol <em>v</em> dietary saturated fat in metabolic ward experiments, by different experimental design. (The equations take account of which experiments were part of the same study; dotted lines represent a typical intake of saturated fat (15% of dietary calories), and this is used as an intercept for the regression equations; no adjustments are made for total energy intake or any other aspects of experimental diets)</p><div class="sb-div caption-clear"></div></div></div>"><img class="fragment-image" src="https://www.bmj.com/content/bmj/314/7074/112/F1.medium.gif" alt="FIG 1"/></a></div></div><div xmlns:xhtml="http://www.w3.org/1999/xhtml" class="fig-caption"><span class="fig-label">FIG 1</span> <p id="p-21" class="first-child">Univariate multilevel regression slopes of blood total cholesterol <em>v</em> dietary saturated fat in metabolic ward experiments, by different experimental design. (The equations take account of which experiments were part of the same study; dotted lines represent a typical intake of saturated fat (15% of dietary calories), and this is used as an intercept for the regression equations; no adjustments are made for total energy intake or any other aspects of experimental diets)</p><div class="sb-div caption-clear"></div></div><ul class="highwire-figure-links list-inline"><li class="download-fig first"><a href="https://www.bmj.com/content/bmj/314/7074/112/F1.large.jpg?download=true" class="highwire-figure-link highwire-figure-link-download" title="Download FIG 1">Download figure</a></li> <li class="new-tab"><a href="https://www.bmj.com/content/bmj/314/7074/112/F1.large.jpg" class="highwire-figure-link highwire-figure-link-newtab" target="_blank">Open in new tab</a></li> <li class="download-ppt last"><a href="/highwire/powerpoint/606367" class="highwire-figure-link highwire-figure-link-ppt">Download powerpoint</a></li> </ul></div></div><div class="fig-caption" xmlns:xhtml="http://www.w3.org/1999/xhtml"></div></div> <p id="p-22">Such univariate analyses might be misleading, however, because isocaloric increases in one type of fat in many of the experiments were accompanied by decreases in other dietary fats or in dietary cholesterol. Multivariate analyses were therefore also performed, which assessed isocaloric replacement of complex carbohydrates by particular lipids after simultaneous adjustment for other dietary factors (and, less importantly, for age and initial body weight). Thus, for example, in the multivariate analyses “effects of saturated fat” would actually mean “effects of replacing carbohydrate isocalorically by saturated fat.” These produced smaller regression coefficients for blood total cholesterol than did the univariate analyses (table <a id="xref-table-wrap-1-2" class="xref-table" href="#T1">1</a>). Different types of experimental design with solid foods produced similar multivariate coefficients for the effects of specific fats on blood total cholesterol (fig <a id="xref-fig-2-1" class="xref-fig" href="#F2">2</a>), with smaller effects for the liquid formula diets. (Similar multivariate associations of blood total cholesterol with intake of various types of fat were observed in men and women; over or under age 35; over or under 70 kg body weight; over or under 2800 daily dietary calories; over or under 300 mg daily dietary cholesterol; and in studies of 2-4, 4-6, and over 6 weeks' duration (data not shown).) If, to ensure that attention is restricted only to randomised evidence, all results from studies of Latin square or sequential designs are ignored, then the overall findings for solid food diets would not be materially altered (fig <a id="xref-fig-2-2" class="xref-fig" href="#F2">2</a>).</p> <div id="F2" class="fig pos-float odd"><div class="fig-inline"><div class="highwire-figure"><div class="fig-inline-img-wrapper"><div class="fig-inline-img"><a href="https://www.bmj.com/content/bmj/314/7074/112/F2.large.jpg?width=800&height=600" title="Multivariate regression coefficients of effects of dietary saturated, polyunsaturated, and monounsaturated fats on blood total cholesterol concentration in metabolic ward studies. (Studies with crossover or parallel design were randomised or matched, but those with Latin square or sequential design were not; the area of the squares is proportional to amount of statistical information; dotted lines represent overall coefficients for all experiments with solid foods)" class="colorbox fragment-images colorbox-load" rel="gallery-fragment-images" data-figure-caption="<div class="highwire-markup"><div class="fig-caption" xmlns:xhtml="http://www.w3.org/1999/xhtml"></div></div>"><img class="fragment-image" src="https://www.bmj.com/content/bmj/314/7074/112/F2.medium.gif" alt="FIG 2"/></a></div></div><div xmlns:xhtml="http://www.w3.org/1999/xhtml" class="fig-caption"><span class="fig-label">FIG 2</span> <p id="p-23" class="first-child">Multivariate regression coefficients of effects of dietary saturated, polyunsaturated, and monounsaturated fats on blood total cholesterol concentration in metabolic ward studies. (Studies with crossover or parallel design were randomised or matched, but those with Latin square or sequential design were not; the area of the squares is proportional to amount of statistical information; dotted lines represent overall coefficients for all experiments with solid foods)</p><div class="sb-div caption-clear"></div></div><ul class="highwire-figure-links list-inline"><li class="download-fig first"><a href="https://www.bmj.com/content/bmj/314/7074/112/F2.large.jpg?download=true" class="highwire-figure-link highwire-figure-link-download" title="Download FIG 2">Download figure</a></li> <li class="new-tab"><a href="https://www.bmj.com/content/bmj/314/7074/112/F2.large.jpg" class="highwire-figure-link highwire-figure-link-newtab" target="_blank">Open in new tab</a></li> <li class="download-ppt last"><a href="/highwire/powerpoint/606373" class="highwire-figure-link highwire-figure-link-ppt">Download powerpoint</a></li> </ul></div></div><div class="fig-caption" xmlns:xhtml="http://www.w3.org/1999/xhtml"></div></div> </div> <div id="sec-9" class="subsection"> <h3>Multivariate analyses for low density lipoprotein and high density lipoprotein cholesterol</h3> <p id="p-24">A subset of 227 of the solid food experiments also reported blood low density lipoprotein and high density lipoprotein cholesterol. Multivariate analyses indicated that isocaloric increases in saturated fat intake were associated with highly significant increases in low density lipoprotein cholesterol and smaller increases in high density lipoprotein cholesterol, as were increases in dietary cholesterol (table <a id="xref-table-wrap-1-3" class="xref-table" href="#T1">1</a>). Conversely, increases in polyunsaturated fat intake significantly decreased low density lipoprotein cholesterol and increased high density lipoprotein cholesterol, while monounsaturated fat had no significant effect on low density lipoprotein cholesterol but did increase high density lipoprotein cholesterol.</p> </div> <div id="sec-10" class="subsection"> <h3>Effects of realistic dietary changes</h3> <p id="p-25">The multivariate analyses indicated that isocaloric replacement of saturated fats equivalent to 10% of dietary calories by complex carbohydrates would typically be associated with a reduction in blood total cholesterol of 0.52 (SE 0.03) mmol/l (table <a id="xref-table-wrap-2-1" class="xref-table" href="#T2">2</a>). Isocaloric replacement by polyunsaturated fat of carbohydrates equivalent to 5% of dietary calories would be expected to reduce blood cholesterol by a further 0.13 (0.02) mmol/l, whereas changes in intake of monounsaturated fat seemed to have little effect. Isocaloric replacement of saturated fats by unsaturated fats produced about three times the reduction in blood cholesterol produced by replacement of total fat by complex carbohydrates (table <a id="xref-table-wrap-2-2" class="xref-table" href="#T2">2</a>). A reduction of 200 mg/day in dietary cholesterol would be associated with a further reduction in blood cholesterol of 0.13 (0.02) mmol/l. Together, the estimated effect of these isocaloric dietary changes would be to reduce blood total cholesterol by 0.76 mmol/l (SE 0.03, 99% confidence interval 0.67 to 0.85) (fig <a id="xref-fig-3-1" class="xref-fig" href="#F3">3</a>), consisting of a reduction in low density lipoprotein cholesterol of 0.62 (0.04) mmol/l and in high density lipoprotein cholesterol of 0.10 (0.02) mmol/l (table <a id="xref-table-wrap-2-3" class="xref-table" href="#T2">2</a>).</p> <div class="table pos-float" id="T2"><div class="table"><div class="table-caption"><span class="table-label">Table 2</span> <p id="p-26" class="first-child">Mean daily intake of dietary fats in 395 solid food experiments compared with average diet for British men and estimated changes in blood total cholesterol (from all 395 solid food experiments) and in low density lipoprotein and high density lipoprotein cholesterol (from 227 solid food experiments) associated with particular changes in intake of fats</p><div class="sb-div caption-clear"></div></div><div class="table-inline"><div class="callout"><span>View this table:</span><ul class="callout-links"><li><a href="/highwire/markup/606390/expansion?width=1000&height=500&iframe=true&postprocessors=highwire_figures%2Chighwire_math" class="colorbox colorbox-load table-expand-popup" rel="gallery-fragment-tables">View popup</a></li><li><a href="" class="table-expand-inline" data-table-url="/highwire/markup/606390/expansion?postprocessors=highwire_figures%2Chighwire_math">View inline</a></li></ul></div></div></div><div></div></div> </div> <div id="sec-11" class="subsection"> <h3>Individual saturated fats</h3> <p id="p-28">Altogether, 134 of the solid food experiments provided information on dietary intake of the major individual saturated fatty acids: laurate (C12:0), myristate (C14:0), palmitate (C16:0), and stearate (C18:0). Intake of the first three was positively related with blood cholesterol concentration, such that halving intake of each isocalorically would be expected to reduce blood total cholesterol by 0.32 (0.04) mmol/l (table <a id="xref-table-wrap-3-1" class="xref-table" href="#T3">3</a>). Stearic acid, however, which accounts for about a quarter of dietary saturated fats, did not seem to be significantly related to blood cholesterol concentration.</p> <div class="table pos-float" id="T3"><div class="table"><div class="table-caption"><span class="table-label">Table 3</span> <p id="p-29" class="first-child">Estimated changes in blood total cholesterol (from 134 solid food experiments) associated with halving the intake of individual saturated fatty acids, adjusted for other saturates, polyunsaturates, monounsaturates, dietary cholesterol, age, and weight</p><div class="sb-div caption-clear"></div></div><div class="table-inline"><div class="callout"><span>View this table:</span><ul class="callout-links"><li><a href="/highwire/markup/606393/expansion?width=1000&height=500&iframe=true&postprocessors=highwire_figures%2Chighwire_math" class="colorbox colorbox-load table-expand-popup" rel="gallery-fragment-tables">View popup</a></li><li><a href="" class="table-expand-inline" data-table-url="/highwire/markup/606393/expansion?postprocessors=highwire_figures%2Chighwire_math">View inline</a></li></ul></div></div></div><div></div></div> <p id="p-32">Forty of the solid food experiments provided information on the dietary intake of <em>trans</em> monounsaturated fats (mainly <em>trans</em> C18:1; elaidate). Multivariate regression coefficients for blood total cholesterol concentration (adjusted for other dietary fats, cholesterol intake, age, and weight) were 0.038 (SE 0.10) for <em>trans</em> monounsaturated fat, which is similar to 0.047 (0.008) for saturated fat in the same analyses. But, <em>trans</em> fatty acids account for only 2% of calories in the British diet,<a id="xref-ref-20-1" class="xref-bibr" href="#ref-20">20</a> so replacing half isocalorically by carbohydrates would be expected to reduce blood total cholesterol by only 0.05 (0.01) mmol/l.</p> <div id="F3" class="fig pos-float odd"><div class="fig-inline"><div class="highwire-figure"><div class="fig-inline-img-wrapper"><div class="fig-inline-img"><a href="https://www.bmj.com/content/bmj/314/7074/112/F3.large.jpg?width=800&height=600" title="Mean (SE) changes in blood total cholesterol concentration associated with replacing dietary saturated fat by polyunsaturated and monounsaturated fats and with reducing dietary cholesterol" class="colorbox fragment-images colorbox-load" rel="gallery-fragment-images" data-figure-caption="<div class="highwire-markup"><div class="fig-caption" xmlns:xhtml="http://www.w3.org/1999/xhtml"></div></div>"><img class="fragment-image" src="https://www.bmj.com/content/bmj/314/7074/112/F3.medium.gif" alt="FIG 3"/></a></div></div><div xmlns:xhtml="http://www.w3.org/1999/xhtml" class="fig-caption"><span class="fig-label">FIG 3</span> <p id="p-33" class="first-child">Mean (SE) changes in blood total cholesterol concentration associated with replacing dietary saturated fat by polyunsaturated and monounsaturated fats and with reducing dietary cholesterol</p><div class="sb-div caption-clear"></div></div><ul class="highwire-figure-links list-inline"><li class="download-fig first"><a href="https://www.bmj.com/content/bmj/314/7074/112/F3.large.jpg?download=true" class="highwire-figure-link highwire-figure-link-download" title="Download FIG 3">Download figure</a></li> <li class="new-tab"><a href="https://www.bmj.com/content/bmj/314/7074/112/F3.large.jpg" class="highwire-figure-link highwire-figure-link-newtab" target="_blank">Open in new tab</a></li> <li class="download-ppt last"><a href="/highwire/powerpoint/606379" class="highwire-figure-link highwire-figure-link-ppt">Download powerpoint</a></li> </ul></div></div><div class="fig-caption" xmlns:xhtml="http://www.w3.org/1999/xhtml"></div></div> </div> </div><div class="section" id="sec-12"> <h2>Discussion</h2> <p id="p-34">Because of the opposing effects on vascular disease of reductions in low density lipoprotein and high density lipoprotein, it is not sufficient to consider the effects of diet only on total blood cholesterol. Overall, because their effect on blood cholesterol is strong and the Western dietary intake is substantial, the key dietary factor in these studies was the intake of saturated fats. The present results indicate that isocaloric replacement of 60% of saturated fat by complex carbohydrates in the British diet would reduce blood total cholesterol by 0.5 mmol/l and low density lipoprotein cholesterol by 0.4 mmol/l, irrespective of sex, age, and body weight. Intake of polyunsaturated fat is also important, with effects that are about half as strong–in the opposite direction–as those of saturated fats. Intake of monounsaturated fat had no significant effect on total or low density lipoprotein cholesterol despite raising high density lipoprotein cholesterol by about as much as polyunsaturates. The combined effect of changing the type, but not the amount, of dietary fat by replacement of 10% of dietary calories from saturates by monounsaturates (5%) and by polyunsaturates (5%), together with consuming 200 mg less dietary cholesterol, would be a reduction in blood cholesterol of about 0.8 mmol/l, with the reduction chiefly in low density lipoprotein cholesterol (fig <a id="xref-fig-3-2" class="xref-fig" href="#F3">3</a>).</p> <p id="p-35">Isocaloric dietary changes such as these, which affect only the type but not the amount of dietary fat, are relevant to the control of plasma low density lipoprotein cholesterol but not to the control of obesity. Caloric restriction should eventually lead to weight loss, but this review has studied only isocaloric change. Table <a id="xref-table-wrap-2-4" class="xref-table" href="#T2">2</a> indicates that if total dietary fat is reduced isocalorically by replacement with complex carbohydrates rather than with unsaturated fats, then the unwanted reduction in high density lipoprotein cholesterol could be so great that the ratio of low density lipoprotein to high density lipoprotein cholesterol would not be much affected.</p> <p id="p-36">Saturated fats with different chain lengths may have different effects, but, although intake of C18:0 fatty acids seemed less relevant than C12:0-C16:0, the evidence was limited and further direct comparisons are needed. The evidence on <em>cis</em> and <em>trans</em> unsaturated fats is also limited: <em>trans</em> unsaturated fats may be similar in effect to saturates, but intake of them is generally low in most people, and so their relevance to blood lipid concentrations is probably small. This review has not, however, tested the hypothesis<a id="xref-ref-21-1" class="xref-bibr" href="#ref-21">21</a> that <em>trans</em> unsaturates from hydrogenated vegetable oil differ in their effects from natural <em>trans</em> unsaturates.</p> <div id="sec-13" class="subsection"> <h3>Conclusion</h3> <p id="p-37">The reduction in blood cholesterol concentration shown by this review with isocaloric replacement of saturated by unsaturated fats appears within just a few weeks and is greater than is sometimes appreciated.<a id="xref-ref-5-2" class="xref-bibr" href="#ref-5">5</a> Previous reviews of the effects of dietary fatty acids have yielded slightly different results from ours. An analysis of 27 studies involving 65 experiments also concluded that replacement of saturates by unsaturates produced substantial changes in the blood lipoprotein profile,<a id="xref-ref-3-2" class="xref-bibr" href="#ref-3">3</a> but the size of changes suggested by our overview are greater. Another review of 248 metabolic ward experiments yielded similar conclusions for the effects of fatty acids on blood total cholesterol but was unable to reach any conclusions for lipoprotein fractions.<a id="xref-ref-4-2" class="xref-bibr" href="#ref-4">4</a> Discrepant results from earlier reviews or individual studies<a id="xref-ref-3-3" class="xref-bibr" href="#ref-3">3</a> <a id="xref-ref-4-3" class="xref-bibr" href="#ref-4">4</a> <a id="xref-ref-15-2" class="xref-bibr" href="#ref-15">15</a> <a id="xref-ref-16-2" class="xref-bibr" href="#ref-16">16</a> <a id="xref-ref-22-1" class="xref-bibr" href="#ref-22">22</a> reinforce the need for periodically updated meta-analyses<a id="xref-ref-12-2" class="xref-bibr" href="#ref-12">12</a> of all available evidence from metabolic ward studies. (We restricted our attention to such studies because the weaker results from non-experimental dietary studies in community subjects may chiefly reflect poor compliance<a id="xref-ref-5-3" class="xref-bibr" href="#ref-5">5</a><a id="xref-ref-6-2" class="xref-bibr" href="#ref-6">6</a><a id="xref-ref-7-2" class="xref-bibr" href="#ref-7">7</a><a id="xref-ref-8-2" class="xref-bibr" href="#ref-8">8</a><a id="xref-ref-9-2" class="xref-bibr" href="#ref-9">9</a><a id="xref-ref-10-2" class="xref-bibr" href="#ref-10">10</a><a id="xref-ref-11-2" class="xref-bibr" href="#ref-11">11</a>.)</p> <p id="p-38">Although dietary change is difficult, these findings are relevant to countries such as Britain, where saturated fats provide 15-17% of dietary calories (chiefly in dairy produce, meat, oils, spreads, eggs, and confectionery) and where the daily cholesterol intake is 280-390 mg (chiefly in meat and eggs).<a id="xref-ref-20-2" class="xref-bibr" href="#ref-20">20</a> <a id="xref-ref-23-1" class="xref-bibr" href="#ref-23">23</a> Table <a id="xref-table-wrap-2-5" class="xref-table" href="#T2">2</a> and figure <a id="xref-fig-3-3" class="xref-fig" href="#F3">3</a> show that changes in dietary fats and cholesterol that many should find practicable would typically reduce blood cholesterol by about 0.8 mmol/l (equivalent to a 10-15% reduction), with large beneficial decreases low density lipoprotein cholesterol concentration and only small adverse decreases in high density lipoprotein cholesterol. The effect on vascular disease of a prolonged difference of 0.8 mmol/l in blood cholesterol concentration depends on the relative importance at different ages of the benefits of reducing low density lipoprotein and the hazards of reducing high density lipoprotein cholesterol, which require further study.</p> <div class="table pos-float" id="T4"><div class="table"><div class="table-caption"><span class="table-label">Table A1</span> <p id="p-39" class="first-child">Metabolic ward studies included in the meta-analysis</p><div class="sb-div caption-clear"></div></div><div class="table-inline"><div class="callout"><span>View this table:</span><ul class="callout-links"><li><a href="/highwire/markup/606399/expansion?width=1000&height=500&iframe=true&postprocessors=highwire_figures%2Chighwire_math" class="colorbox colorbox-load table-expand-popup" rel="gallery-fragment-tables">View popup</a></li><li><a href="" class="table-expand-inline" data-table-url="/highwire/markup/606399/expansion?postprocessors=highwire_figures%2Chighwire_math">View inline</a></li></ul></div></div></div><div></div></div> </div> </div><div class="section ack" id="ack-1"><h2>Acknowledgments</h2> <p id="p-43">Alison Mills and Joyce Hughes, MAFF Nutrition Branch of the Ministry of Agriculture, Fisheries and Foods, provided British dietary data. Vivien Reid, Anthony Keech, and Jane Armitage provided helpful comments, as did the anonymous referees.</p> <p id="p-44">Funding: British Heart Foundation and Medical Research Council.</p> <p id="p-45">Conflict of interest: None.</p> </div><div class="section ref-list" id="ref-list-1"><h2>References</h2><ol class="cit-list ref-use-labels"><li><span class="ref-label">1.</span><a class="rev-xref-ref" href="#xref-ref-1-1" title="View reference 1. in text" id="ref-1">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.1"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Ulbricht</span> <span class="cit-name-given-names">TLV</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Southgate</span> <span class="cit-name-given-names">DAT</span></span></li></ol><cite>. <span class="cit-article-title">Coronary heart disease: seven dietary factors.</span> <abbr class="cit-jnl-abbrev">Lancet</abbr> <span class="cit-pub-date">1991</span>;<span class="cit-vol">338</span>:<span class="cit-fpage">985</span>–<span class="cit-lpage">92</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">2.</span><a class="rev-xref-ref" href="#xref-ref-2-1" title="View reference 2. in text" id="ref-2">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.2"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Grundy</span> <span class="cit-name-given-names">SM</span></span></li></ol><cite>. <span class="cit-article-title">Dietary influences on serum lipids and lipoproteins.</span> <abbr class="cit-jnl-abbrev">J Lipid Res</abbr> <span class="cit-pub-date">1990</span>;<span class="cit-vol">31</span>:<span class="cit-fpage">1149</span>–<span class="cit-lpage">72</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">3.</span><a class="rev-xref-ref" href="#xref-ref-3-1" title="View reference 3. in text" id="ref-3">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.3"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Mensink</span> <span class="cit-name-given-names">RP</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Katan</span> <span class="cit-name-given-names">MB</span></span></li></ol><cite>. <span class="cit-article-title">Effect of dietary fatty acids on serum lipids and lipoproteins–a meta-analysis of 27 trials.</span> <abbr class="cit-jnl-abbrev">Arterioscler Thromb</abbr> <span class="cit-pub-date">1992</span>;<span class="cit-vol">12</span>:<span class="cit-fpage">911</span>–<span class="cit-lpage">9</span>.</cite></div><div class="cit-extra"><a href="{openurl}?query=rft.jtitle%253DArteriosclerosis%252C%2BThrombosis%252C%2Band%2BVascular%2BBiology%26rft.stitle%253DArterioscler.%2BThromb.%2BVasc.%2BBio.%26rft.issn%253D0276-5047%26rft.aulast%253DMensink%26rft.auinit1%253DR.%2BP.%26rft.volume%253D12%26rft.issue%253D8%26rft.spage%253D911%26rft.epage%253D919%26rft.atitle%253DEffect%2Bof%2Bdietary%2Bfatty%2Bacids%2Bon%2Bserum%2Blipids%2Band%2Blipoproteins.%2BA%2Bmeta-%2Banalysis%2Bof%2B27%2Btrials%26rft_id%253Dinfo%253Apmid%252F1386252%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx" class="cit-ref-sprinkles cit-ref-sprinkles-openurl cit-ref-sprinkles-open-url"><span>OpenUrl</span></a><a href="/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NzoiYXR2YmFoYSI7czo1OiJyZXNpZCI7czo4OiIxMi84LzkxMSI7czo0OiJhdG9tIjtzOjIyOiIvYm1qLzMxNC83MDc0LzExMi5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=" class="cit-ref-sprinkles cit-ref-sprinkles-ijlink"><span><span class="cit-reflinks-abstract">Abstract</span><span class="cit-sep cit-reflinks-variant-name-sep">/</span><span class="cit-reflinks-full-text"><span class="free-full-text">FREE </span>Full Text</span></span></a></div></div></li><li><span class="ref-label">4.</span><a class="rev-xref-ref" href="#xref-ref-4-1" title="View reference 4. in text" id="ref-4">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.4"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Hegsted</span> <span class="cit-name-given-names">DM</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Austman</span> <span class="cit-name-given-names">LM</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Johnson</span> <span class="cit-name-given-names">JA</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Dallal</span> <span class="cit-name-given-names">GE</span></span></li></ol><cite>. <span class="cit-article-title">Dietary fat and serum lipids: an evaluation of the experimental data.</span> <abbr class="cit-jnl-abbrev">Am J Clin Nutr</abbr> <span class="cit-pub-date">1993</span>;<span class="cit-vol">57</span>:<span class="cit-fpage">875</span>–<span class="cit-lpage">83</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">5.</span><a class="rev-xref-ref" href="#xref-ref-5-1" title="View reference 5. in text" id="ref-5">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.5"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Ramsay</span> <span class="cit-name-given-names">LE</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Yeo</span> <span class="cit-name-given-names">WW</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Jackson</span> <span class="cit-name-given-names">PR</span></span></li></ol><cite>. <span class="cit-article-title">Dietary reduction of serum cholesterol concentration: time to think again.</span> <abbr class="cit-jnl-abbrev">BMJ</abbr> <span class="cit-pub-date">1991</span>;<span class="cit-vol">303</span>:<span class="cit-fpage">953</span>–<span class="cit-lpage">7</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">6.</span><a class="rev-xref-ref" href="#xref-ref-6-1" title="View reference 6. in text" id="ref-6">↵</a><div class="cit ref-cit ref-book" id="cit-314.7074.112.6"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Keys</span> <span class="cit-name-given-names">A</span></span></li></ol><cite>. <span class="cit-source">Seven countries: a multivariate analysis of death and coronary heart disease</span>. <span class="cit-publ-loc">Cambridge</span>: <span class="cit-publ-name">Harvard University Press</span>, <span class="cit-pub-date">1980</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">7.</span><a class="rev-xref-ref" href="#xref-ref-7-1" title="View reference 7. in text" id="ref-7">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.7"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Jacobs</span> <span class="cit-name-given-names">DR</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Anderson</span> <span class="cit-name-given-names">JT</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Blackburn</span> <span class="cit-name-given-names">H</span></span></li></ol><cite>. <span class="cit-article-title">Diet and serum cholesterol: do zero correlations negate the relationship?</span> <abbr class="cit-jnl-abbrev">Am J Epidemiol</abbr> <span class="cit-pub-date">1979</span>;<span class="cit-vol">110</span>:<span class="cit-fpage">77</span>–<span class="cit-lpage">87</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">8.</span><a class="rev-xref-ref" href="#xref-ref-8-1" title="View reference 8. in text" id="ref-8">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.8"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Liu</span> <span class="cit-name-given-names">K</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Stamler</span> <span class="cit-name-given-names">J</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Dyer</span> <span class="cit-name-given-names">A</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">McKeever</span> <span class="cit-name-given-names">J</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">McKeever</span> <span class="cit-name-given-names">P</span></span></li></ol><cite>. <span class="cit-article-title">Statistical methods to assess and minimize the role of intra-individual variability in obscuring the relationship between dietary lipids and serum cholesterol.</span> <abbr class="cit-jnl-abbrev">J Chron Dis</abbr> <span class="cit-pub-date">1978</span>;<span class="cit-vol">31</span>:<span class="cit-fpage">339</span>–<span class="cit-lpage">418</span>.</cite></div><div class="cit-extra"><a href="{openurl}?query=rft.jtitle%253DJ%2BChron%2BDis%26rft.volume%253D31%26rft.spage%253D339%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx" class="cit-ref-sprinkles cit-ref-sprinkles-openurl cit-ref-sprinkles-open-url"><span>OpenUrl</span></a></div></div></li><li><span class="ref-label">9.</span><a class="rev-xref-ref" href="#xref-ref-9-1" title="View reference 9. in text" id="ref-9">↵</a><div class="cit ref-cit ref-book" id="cit-314.7074.112.9"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Bloemberg</span> <span class="cit-name-given-names">B</span></span></li></ol><cite>. <span class="cit-article-title">On the effect of measurement error in nutritional epidemiology using dietary history and food frequency methodology [thesis]</span>. <span class="cit-publ-loc">Leiden</span>: <span class="cit-publ-name">University of Leiden</span>, <span class="cit-pub-date">1993</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">10.</span><a class="rev-xref-ref" href="#xref-ref-10-1" title="View reference 10. in text" id="ref-10">↵</a><div class="cit ref-cit ref-book" id="cit-314.7074.112.10"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Willett</span> <span class="cit-name-given-names">W</span></span></li></ol><cite>. <span class="cit-source">Nutritional epidemiology</span>. <span class="cit-publ-loc">Oxford</span>: <span class="cit-publ-name">Oxford University Press</span>, <span class="cit-pub-date">1990</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">11.</span><a class="rev-xref-ref" href="#xref-ref-11-1" title="View reference 11. in text" id="ref-11">↵</a><div class="cit ref-cit ref-book" id="cit-314.7074.112.11"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Margaretts</span> <span class="cit-name-given-names">BM</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Nelson</span> <span class="cit-name-given-names">M</span></span></li></ol><cite> eds. <span class="cit-source">Design concepts in nutritional epidemiology</span>. <span class="cit-publ-loc">Oxford</span>: <span class="cit-publ-name">Oxford University Press</span>, <span class="cit-pub-date">1991</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">12.</span><a class="rev-xref-ref" href="#xref-ref-12-1" title="View reference 12. in text" id="ref-12">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.12"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Collins</span> <span class="cit-name-given-names">R</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Gray</span> <span class="cit-name-given-names">R</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Godwin</span> <span class="cit-name-given-names">J</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Peto</span> <span class="cit-name-given-names">R</span></span></li></ol><cite>. <span class="cit-article-title">Avoidance of large biases and large random errors in the assessment of moderate treatment effects: the need for systematic overviews.</span> <abbr class="cit-jnl-abbrev">Stat Med</abbr> <span class="cit-pub-date">1987</span>;<span class="cit-vol">6</span>:<span class="cit-fpage">245</span>–<span class="cit-lpage">50</span></cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">13.</span><a class="rev-xref-ref" href="#xref-ref-13-1" title="View reference 13. in text" id="ref-13">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.13" data-doi="10.1016/0026-0495(89)90258-8"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Mensink</span> <span class="cit-name-given-names">RP</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">de Groot</span> <span class="cit-name-given-names">MJM</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">van den Broeke</span> <span class="cit-name-given-names">LT</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Severtijnen-Nobels</span> <span class="cit-name-given-names">AP</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Demacker</span> <span class="cit-name-given-names">PNM</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Katan</span> <span class="cit-name-given-names">MB</span></span></li></ol><cite>. <span class="cit-article-title">Effects of monounsaturated fatty acids v complex carbohydrates on serum lipoproteins and apolipoproteins in healthy men and women.</span> <abbr class="cit-jnl-abbrev">Metabolism</abbr> <span class="cit-pub-date">1989</span>;<span class="cit-vol">38</span>:<span class="cit-fpage">172</span>–<span class="cit-lpage">8</span>.</cite></div><div class="cit-extra"><a href="{openurl}?query=rft.jtitle%253DMetabolism%253A%2B%2Bclinical%2Band%2Bexperimental%26rft.stitle%253DMetabolism%26rft.aulast%253DMensink%26rft.auinit1%253DR.%2BP.%26rft.volume%253D38%26rft.issue%253D2%26rft.spage%253D172%26rft.epage%253D178%26rft.atitle%253DEffects%2Bof%2Bmonounsaturated%2Bfatty%2Bacids%2Bv%2Bcomplex%2Bcarbohydrates%2Bon%2Bserum%2Blipoproteins%2Band%2Bapoproteins%2Bin%2Bhealthy%2Bmen%2Band%2Bwomen.%26rft_id%253Dinfo%253Adoi%252F10.1016%252F0026-0495%252889%252990258-8%26rft_id%253Dinfo%253Apmid%252F2536459%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx" class="cit-ref-sprinkles cit-ref-sprinkles-openurl cit-ref-sprinkles-open-url"><span>OpenUrl</span></a><a href="/lookup/external-ref?access_num=10.1016/0026-0495(89)90258-8&link_type=DOI" class="cit-ref-sprinkles cit-ref-sprinkles-doi cit-ref-sprinkles-crossref"><span>CrossRef</span></a><a href="/lookup/external-ref?access_num=2536459&link_type=MED&atom=%2Fbmj%2F314%2F7074%2F112.atom" class="cit-ref-sprinkles cit-ref-sprinkles-medline"><span>PubMed</span></a><a href="/lookup/external-ref?access_num=A1989R950000014&link_type=ISI" class="cit-ref-sprinkles cit-ref-sprinkles-newisilink cit-ref-sprinkles-webofscience"><span>Web of Science</span></a></div></div></li><li><span class="ref-label">14.</span><a class="rev-xref-ref" href="#xref-ref-14-1" title="View reference 14. in text" id="ref-14">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.14"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Mattson</span> <span class="cit-name-given-names">FH</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Grundy</span> <span class="cit-name-given-names">SM</span></span></li></ol><cite>. <span class="cit-article-title">Comparison of effects of dietary saturated, monounsaturated, and polyunsaturated fatty acids on plasma lipids and lipoproteins in man.</span> <abbr class="cit-jnl-abbrev">J Lipid Res</abbr> <span class="cit-pub-date">1985</span>;<span class="cit-vol">26</span>:<span class="cit-fpage">194</span>–<span class="cit-lpage">202</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">15.</span><a class="rev-xref-ref" href="#xref-ref-15-1" title="View reference 15. in text" id="ref-15">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.15"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Keys</span> <span class="cit-name-given-names">A</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Anderson</span> <span class="cit-name-given-names">JT</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Grande</span> <span class="cit-name-given-names">F</span></span></li></ol><cite>. <span class="cit-article-title">Prediction of serum cholesterol responses of man to changes in fats in the diet</span>. <abbr class="cit-jnl-abbrev">Lancet</abbr> <span class="cit-pub-date">1957</span>;<span class="cit-vol">ii</span>:<span class="cit-fpage">959</span>–<span class="cit-lpage">66</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">16.</span><a class="rev-xref-ref" href="#xref-ref-16-1" title="View reference 16. in text" id="ref-16">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.16"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Hegsted</span> <span class="cit-name-given-names">DM</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">McGandy</span> <span class="cit-name-given-names">RB</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Myers</span> <span class="cit-name-given-names">ML</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Stare</span> <span class="cit-name-given-names">FJ</span></span></li></ol><cite>. <span class="cit-article-title">Quantitative effects of dietary fat on serum cholesterol in man.</span> <abbr class="cit-jnl-abbrev">Am J Clin Nutr</abbr> <span class="cit-pub-date">1965</span>;<span class="cit-vol">17</span>:<span class="cit-fpage">281</span>–<span class="cit-lpage">95</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">17.</span><a class="rev-xref-ref" href="#xref-ref-17-1" title="View reference 17. in text" id="ref-17">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.17"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Mensink</span> <span class="cit-name-given-names">RP</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Katan</span> <span class="cit-name-given-names">MB</span></span></li></ol><cite>. <span class="cit-article-title">Effect of dietary trans fatty acids on high-density and low density lipoprotein cholesterol levels in healthy subjects.</span> <abbr class="cit-jnl-abbrev">N Engl J Med</abbr> <span class="cit-pub-date">1990</span>;<span class="cit-vol">323</span>:<span class="cit-fpage">439</span>–<span class="cit-lpage">45</span>.</cite></div><div class="cit-extra"><a href="{openurl}?query=rft.jtitle%253DNew%2BEngland%2BJournal%2Bof%2BMedicine%26rft.stitle%253DNEJM%26rft.issn%253D0028-4793%26rft.aulast%253DMensink%26rft.auinit1%253DR.%2BP.%26rft.volume%253D323%26rft.issue%253D7%26rft.spage%253D439%26rft.epage%253D445%26rft.atitle%253DEffect%2Bof%2Bdietary%2Btrans%2Bfatty%2Bacids%2Bon%2Bhigh-density%2Band%2Blow-density%2Blipoprotein%2Bcholesterol%2Blevels%2Bin%2Bhealthy%2Bsubjects%26rft_id%253Dinfo%253Apmid%252F2374566%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx" class="cit-ref-sprinkles cit-ref-sprinkles-openurl cit-ref-sprinkles-open-url"><span>OpenUrl</span></a><a href="/lookup/external-ref?access_num=2374566&link_type=MED&atom=%2Fbmj%2F314%2F7074%2F112.atom" class="cit-ref-sprinkles cit-ref-sprinkles-medline"><span>PubMed</span></a><a href="/lookup/external-ref?access_num=A1990DU27300003&link_type=ISI" class="cit-ref-sprinkles cit-ref-sprinkles-newisilink cit-ref-sprinkles-webofscience"><span>Web of Science</span></a></div></div></li><li><span class="ref-label">18.</span><a class="rev-xref-ref" href="#xref-ref-18-1" title="View reference 18. in text" id="ref-18">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.18"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Zock</span> <span class="cit-name-given-names">PL</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">de Vries</span> <span class="cit-name-given-names">JH</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Katan</span> <span class="cit-name-given-names">MB</span></span></li></ol><cite>. <span class="cit-article-title">Impact of myristic acid versus palmitic acid on serum lipid and lipoprotein levels in healthy women and men.</span> <abbr class="cit-jnl-abbrev">Arterioscler Thromb</abbr> <span class="cit-pub-date">1994</span>;<span class="cit-vol">14</span>:<span class="cit-fpage">567</span>–<span class="cit-lpage">75</span>.</cite></div><div class="cit-extra"><a href="{openurl}?query=rft.jtitle%253DArteriosclerosis%252C%2BThrombosis%252C%2Band%2BVascular%2BBiology%26rft.stitle%253DArterioscler.%2BThromb.%2BVasc.%2BBio.%26rft.issn%253D0276-5047%26rft.aulast%253DZock%26rft.auinit1%253DP.%2BL.%26rft.volume%253D14%26rft.issue%253D4%26rft.spage%253D567%26rft.epage%253D575%26rft.atitle%253DImpact%2Bof%2Bmyristic%2Bacid%2Bversus%2Bpalmitic%2Bacid%2Bon%2Bserum%2Blipid%2Band%2Blipoprotein%2Blevels%2Bin%2Bhealthy%2Bwomen%2Band%2Bmen%26rft_id%253Dinfo%253Apmid%252F8148355%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx" class="cit-ref-sprinkles cit-ref-sprinkles-openurl cit-ref-sprinkles-open-url"><span>OpenUrl</span></a><a href="/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NzoiYXR2YmFoYSI7czo1OiJyZXNpZCI7czo4OiIxNC80LzU2NyI7czo0OiJhdG9tIjtzOjIyOiIvYm1qLzMxNC83MDc0LzExMi5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=" class="cit-ref-sprinkles cit-ref-sprinkles-ijlink"><span><span class="cit-reflinks-abstract">Abstract</span><span class="cit-sep cit-reflinks-variant-name-sep">/</span><span class="cit-reflinks-full-text"><span class="free-full-text">FREE </span>Full Text</span></span></a></div></div></li><li><span class="ref-label">19.</span><a class="rev-xref-ref" href="#xref-ref-19-1" title="View reference 19. in text" id="ref-19">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.19"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Hegsted</span> <span class="cit-name-given-names">DM</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Nicolosi</span> <span class="cit-name-given-names">RJ</span></span></li></ol><cite>. <span class="cit-article-title">Do formula diets attenuate the serum cholesterol response to dietary fats?</span> <abbr class="cit-jnl-abbrev">J Vasc Med Biol</abbr> <span class="cit-pub-date">1990</span>;<span class="cit-vol">2</span>:<span class="cit-fpage">68</span>–<span class="cit-lpage">73</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">20.</span><a class="rev-xref-ref" href="#xref-ref-20-1" title="View reference 20. in text" id="ref-20">↵</a><div class="cit ref-cit ref-book" id="cit-314.7074.112.20"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Gregory</span> <span class="cit-name-given-names">J</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Foster</span> <span class="cit-name-given-names">K</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Tyler</span> <span class="cit-name-given-names">H</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Wiseman</span> <span class="cit-name-given-names">M</span></span></li></ol><cite>. <span class="cit-source">The dietary and nutritional survey of British adults</span>. <span class="cit-publ-loc">London</span>: <span class="cit-publ-name">HMSO</span>, <span class="cit-pub-date">1990</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">21.</span><a class="rev-xref-ref" href="#xref-ref-21-1" title="View reference 21. in text" id="ref-21">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.21"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Willett</span> <span class="cit-name-given-names">WC</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Stampfer</span> <span class="cit-name-given-names">MJ</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Manson</span> <span class="cit-name-given-names">JE</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Colditz</span> <span class="cit-name-given-names">GA</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Speizer</span> <span class="cit-name-given-names">FE</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Rosner</span> <span class="cit-name-given-names">BA</span></span>, </li><li><span class="cit-etal">et al</span></li></ol><cite>. <span class="cit-article-title">Intake of trans fatty acids and risk of coronary heart disease among women.</span> <abbr class="cit-jnl-abbrev">Lancet</abbr> <span class="cit-pub-date">1993</span>;<span class="cit-vol">341</span>:<span class="cit-fpage">581</span>–<span class="cit-lpage">5</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">22.</span><a class="rev-xref-ref" href="#xref-ref-22-1" title="View reference 22. in text" id="ref-22">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.22"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Yu</span> <span class="cit-name-given-names">S</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Derr</span> <span class="cit-name-given-names">TD</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Etherton</span> <span class="cit-name-given-names">TD</span></span>, </li><li><span class="cit-auth"><span class="cit-name-surname">Kris-Etherton</span> <span class="cit-name-given-names">PM</span></span></li></ol><cite>. <span class="cit-article-title">Plasma cholesterol-predictive equations demonstrate that stearic acid is neutral and that monounsaturated fatty acids are hypocholesterolemic.</span> <abbr class="cit-jnl-abbrev">Am J Clin Nutr</abbr> <span class="cit-pub-date">1995</span>;<span class="cit-vol">61</span>:<span class="cit-fpage">1129</span>–<span class="cit-lpage">39</span>.</cite></div><div class="cit-extra"></div></div></li><li><span class="ref-label">23.</span><a class="rev-xref-ref" href="#xref-ref-23-1" title="View reference 23. in text" id="ref-23">↵</a><div class="cit ref-cit ref-journal" id="cit-314.7074.112.23"><div class="cit-metadata"><ol class="cit-auth-list"><li><span class="cit-auth"><span class="cit-name-surname">Bingham</span> <span class="cit-name-given-names">S</span></span></li></ol><cite>. <span class="cit-article-title">Dietary aspects of a health strategy for England.</span> <abbr class="cit-jnl-abbrev">BMJ</abbr> <span class="cit-pub-date">1991</span>;<span class="cit-vol">303</span>:<span class="cit-fpage">353</span>–<span class="cit-lpage">5</span>.</cite></div><div class="cit-extra"></div></div></li></ol></div><span class="highwire-journal-article-marker-end"></span></div><span id="related-urls"></span></div></div> </div> </div> </div> </div> </div> </div></div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-highwire-article-trendmd" > <div class="pane-content"> <div id="trendmd-suggestions"></div> </div> </div> </article> </div> <div class="right-nav col-xs-12 col-sm-4 col-md-4 col-lg-4"> <aside> <div class="panel-pane pane-service-links" > <div class="pane-content"> <div class="service-links"><ul><li class="first"><a href="http://twitter.com/share?url=https%3A//www.bmj.com/content/314/7074/112&count=horizontal&via=&text=Dietary%20lipids%20and%20blood%20cholesterol%3A%20quantitative%20meta-analysis%20of%20metabolic%20ward%20studies&counturl=https%3A//www.bmj.com/content/314/7074/112" class="twitter-share-button service-links-twitter-widget" id="twitter_widget" title="Tweet This" rel="nofollow"><span class="element-invisible">Tweet Widget</span></a></li> <li class="last"><a href="http://www.facebook.com/plugins/like.php?href=https%3A//www.bmj.com/content/314/7074/112&layout=button_count&show_faces=false&action=like&colorscheme=light&width=100&height=21&font=&locale=" id="facebook_like" title="I Like it" class="service-links-facebook-like" rel="nofollow"><span class="element-invisible">Facebook Like</span></a></li> </ul></div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-snippet" > <div class="pane-content"> <div class="oas-ad-middle-1" id="oas-ad-middle-1"> <div class="snippet-content"> <div id="div-gpt-ad-7326006-2"><script> googletag.cmd.push(function() { googletag.display('div-gpt-ad-7326006-2'); }); </script></div> </div> </div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-bmj-article-buttons" > <h2 class="pane-title"> Article tools </h2> <div class="pane-content"> <a href="/content/314/7074/112/rapid-responses" class="citation-rr-link"><em class="bmj-icon blue-icon fa fa-comment"></em>0 responses</a> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-panels-mini pane-jnl-bmj-art-tools" > <div class="pane-content"> <div class="panel-display panel-1col clearfix" id="mini-panel-jnl_bmj_art_tools"> <div class="panel-panel panel-col"> <div><ul><li class="first"><div class="panel-pane pane-custom pane-1" > <div class="pane-content"> <p><i class="bmj-icon fa fa-edit"></i><a href="/content/314/7074/112/submit-a-rapid-response">Respond to this article</a></p> </div> </div> </li> <li><div class="panel-pane pane-bmj-variant-link" > <div class="pane-content"> <i class="bmj-icon fa fa-print"></i><a href="/content/314/7074/112.full-text.print" data-font-icon="fa fa-print">Print</a> </div> </div> </li> <li><div class="panel-pane pane-bmj-minipanel-model-link pane-jnl-bmj-article-page-alerts" > <div class="pane-content"> <div class='minipanel-model-wrapper'><div class='minipanel-model-link-link'><i class="bmj-icon fa fa-bullhorn"></i><a href="/#mini-panel-jnl-bmj-article-page-alerts-1" data-toggle="collapse" role="button" data-font-icon="fa fa-bullhorn">Alerts & updates</a></div><div id="mini-panel-jnl-bmj-article-page-alerts-1" class="panel-collapse collapse"><div class="minipanel-header"><h4 class="minipanel-label">Article alerts</h4><div class="short-description"><div class="alerts-marketing">Please note: your email address is provided to the journal, which may use this information for marketing purposes.</div></div></div><div class="minipanel-body"><div class="panel-display row bootstrap-onecol" id="mini-panel-jnl_bmj_article_page_alerts"> <div class="panel-panel col-xs-12 col-sm-12 col-md-12 col-lg-12"> <div class="panel-pane pane-custom pane-2" > <div class="pane-content"> <h4 class="minipanel-label">Log in or register:</h4> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-alerts-login-form" > <div class="pane-content"> <form action="/content/314/7074/112?tab=article-alert" method="post" id="user-login-form" accept-charset="UTF-8"><div><div class="form-type-textfield form-item-name form-item form-group"> <label for="edit-name">Username <span class="form-required" title="This field is required.">*</span></label> <input class="form-control form-text required" type="text" id="edit-name" name="name" value="" size="15" maxlength="60" /> </div> <div class="form-type-password form-item-pass form-item form-group"> <label for="edit-pass">Password <span class="form-required" title="This field is required.">*</span></label> <input class="form-control form-text required" type="password" id="edit-pass" name="pass" size="15" maxlength="128" /> </div> <input type="hidden" name="form_build_id" value="form-1EU6efCLA3sOQZ-HslQCDVnTEIG1iBP670eUGZYjD2A" /> <input type="hidden" name="form_id" value="highwire_alerts_user_login" /> <input class="btn form-submit" type="submit" id="edit-submit" name="op" value="Log in" /></div></form> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-custom pane-3" id="register-for-alerts" > <div class="pane-content"> <p><a class="btn register-button" href="//myaccount.bmj.com/myaccount/registration.html?regService=bmj-registration&fwdUrl=https://www.bmj.com/content/314/7074/112?tab=article-alert&itemId=pr1906">Register for alerts</a><br /> <div class="alerts-email"><i class="fa fa-info-circle"></i> If you have registered for alerts, you should use your registered email address as your username</div> </div> </div> </div> </div> </div></div></div> </div> </div> </li> <li><div class="panel-pane pane-bmj-minipanel-model-link pane-article-page-citation-download" > <div class="pane-content"> <div class='minipanel-model-wrapper'><div class='minipanel-model-link-link'><i class="bmj-icon fa fa-globe"></i><a href="/#mini-panel-article-page-citation-download-1" data-toggle="collapse" role="button" data-font-icon="fa fa-globe">Citation tools</a></div><div id="mini-panel-article-page-citation-download-1" class="panel-collapse collapse"><div class="minipanel-header"><h4 class="minipanel-label">Download this article to citation manager</h4></div><div class="minipanel-body"><div class="panel-display row bootstrap-onecol" id="mini-panel-article_page_citation_download"> <div class="panel-panel col-xs-12 col-sm-12 col-md-12 col-lg-12"> <div class="panel-pane pane-bmj-citation-export" > <div class="pane-content"> <div> <div class="highwire-citation-info"> <div class="highwire-article-citation highwire-citation-type-highwire-article node522410--3" data-node-nid="522410" id="node-522410--41530954410" data-pisa="bmj;314/7074/112" data-pisa-master="bmj;314/7074/112" data-apath="/bmj/314/7074/112.atom"><div id="jnl_bmj_custom_authors" style="display: none;"><span data-delta="0"><span class="nlm-given-names">Robert</span> <span class="nlm-surname">Clarke</span></span>, <span data-delta="1"><span class="nlm-given-names">Chris</span> <span class="nlm-surname">Frost</span></span>, <span data-delta="2"><span class="nlm-given-names">Rory</span> <span class="nlm-surname">Collins</span></span>, <span data-delta="3"><span class="nlm-given-names">Paul</span> <span class="nlm-surname">Appleby</span></span>, <span data-delta="4"><span class="nlm-given-names">Richard</span> <span class="nlm-surname">Peto</span></span></div> <div class="highwire-cite highwire-cite-highwire-article highwire-citation-bmj-article-citation-export clearfix" > <span class="highwire-cite-authors" ><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> <html><body><span data-delta="0"><span class="nlm-surname">Clarke</span> <span class="nlm-given-names">R</span></span>, <span data-delta="1"><span class="nlm-surname">Frost</span> <span class="nlm-given-names">C</span></span>, <span data-delta="2"><span class="nlm-surname">Collins</span> <span class="nlm-given-names">R</span></span>, <span data-delta="3"><span class="nlm-surname">Appleby</span> <span class="nlm-given-names">P</span></span>, <span data-delta="4"><span class="nlm-surname">Peto</span> <span class="nlm-given-names">R</span></span>. </body></html> </span> <span class="highwire-cite-title article-title">Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies</span> <span class="highwire-cite-metadata" ><span class="highwire-cite-metadata-journal highwire-cite-metadata">BMJ </span><span class="highwire-cite-metadata-date highwire-cite-metadata">1997; </span><span class="highwire-cite-metadata-volume highwire-cite-metadata">314 </span><span class="highwire-cite-metadata-volume highwire-cite-metadata">:112 </span></span> <span class="article-doi" >doi:10.1136/bmj.314.7074.112</span> </div> </div> </div> <div class="highwire-citation-formats"> <div class="highwire-citation-formats-links"> <span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.spage=112&rft.epage&rft.atitle=Dietary%20lipids%20and%20blood%20cholesterol%3A%20quantitative%20meta-analysis%20of%20metabolic%20ward%20studies&rft.volume=314&rft.issue=7074&rft.date=1997-01-11%2008%3A00%3A00&rft.stitle&rft.jtitle=BMJ&rft.au=Clarke%2C+Robert&rft.au=Frost%2C+Chris&rft.au=Collins%2C+Rory&rft.au=Appleby%2C+Paul&rft.au=Peto%2C+Richard"></span><h3></h3><ul class="bmj-citation-links"><li class="first">BibTeX (win & mac)<a href="/highwire/citation/522410/bibtext" class="citation-link btn btn-primary pull-right">Download</a></li> <li>EndNote (tagged)<a href="/highwire/citation/522410/endnote-tagged" class="citation-link btn btn-primary pull-right">Download</a></li> <li>EndNote 8 (xml)<a href="/highwire/citation/522410/endnote-8-xml" class="citation-link btn btn-primary pull-right">Download</a></li> <li>RefWorks Tagged (win & mac)<a href="/highwire/citation/522410/refworks-tagged" class="citation-link btn btn-primary pull-right">Download</a></li> <li>RIS (win only)<a href="/highwire/citation/522410/ris" class="citation-link btn btn-primary pull-right">Download</a></li> <li class="last">Medlars<a href="/highwire/citation/522410/medlars" class="citation-link btn btn-primary pull-right">Download</a></li> </ul> </div> </div> </div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-snippet" > <h2 class="pane-title"> Help </h2> <div class="pane-content"> <div class="jnl-bmj-citation-download-help" id="jnl-bmj-citation-download-help"> <div class="snippet-content"> <div class="citation-help"> <p class="citation-manager">If you are unable to import citations, please contact technical support for your product directly (links go to external sites):</p> <ul> <li><a href="http://www.endnote.com/support/ensupport.asp">EndNote</a></li> <li><a href="http://www.procite.com/support/pcsupport.asp">ProCite</a></li> <li><a href="http://www.refman.com/support/rmsupport.asp">Reference Manager</a></li> <li><a href= "http://www.refworks.com/content/products/content.asp">RefWorks</a></li> <li><a href="http://www.zotero.org/support">Zotero</a></li> </ul> </div> </div> </div> </div> </div> </div> </div> </div></div></div> </div> </div> </li> <li class="last"><div class="panel-pane pane-bmj-permission-link" > <div class="pane-content"> <i class="bmj-icon icon-copyright"></i><a href="https://s100.copyright.com/AppDispatchServlet?publisherName=BMJ&publication=bmj&title=Dietary%20lipids%20and%20blood%20cholesterol%3A%20quantitative%20meta-analysis%20of%20metabolic%20ward%20studies&publicationDate=01/11/1997&author=Robert%20Clarke%2C%20Chris%20Frost%2C%20Rory%20Collins%2C%20Paul%20Appleby%2C%20Richard%20Peto&contentID=10.1136/bmj.314.7074.112&volumeNum=314&issueNum=&startPage=&endPage=&copyright=BMJ%20Publishing%20Group%20Ltd&oa=n&orderBeanReset=1&link_type=PERMISSIONDIRECT&atom=/bmj/314/7074/112.atom" rel="external" class="bmj-permission-link request-permissions" target="_blank" data-font-icon="icon-copyright">Request permissions</a> </div> </div> </li> </ul></div> </div> </div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-panels-mini pane-bmj-article-share-modal" > <div class="pane-content"> <div class="panel-display row bootstrap-onecol" id="mini-panel-bmj_article_share_modal"> <div class="panel-panel col-xs-12 col-sm-12 col-md-12 col-lg-12"> <div class="panel-pane pane-bmj-article-links" > <div class="pane-content"> <div class="bmj-article-links minipanel-model-wrapper"><ul class="links"><li><div class="minipanel-model-link-link"><i class="bmj-icon fa fa-user"></i><a data-font-icon="fa fa-bullhorn" role="button" data-toggle="collapse" href="/#mini-panel-jnl-bmj-article-page-citation" class="collapsed">Author citation</a></div></li></ul><div style="height: 0px;" id="mini-panel-jnl-bmj-article-page-citation" class="panel-collapse collapse"><ul class="links"><li class="0 first"><a href="//www.ncbi.nlm.nih.gov/sites/entrez?cmd=search&db=pubmed&term=Clarke%20Robert%5Bau%5D&dispmax=50" target="_blank">Articles by Robert Clarke</a></li> <li class="1"><a href="//www.ncbi.nlm.nih.gov/sites/entrez?cmd=search&db=pubmed&term=Frost%20Chris%5Bau%5D&dispmax=50" target="_blank">Articles by Chris Frost</a></li> <li class="2"><a href="//www.ncbi.nlm.nih.gov/sites/entrez?cmd=search&db=pubmed&term=Collins%20Rory%5Bau%5D&dispmax=50" target="_blank">Articles by Rory Collins</a></li> <li class="3"><a href="//www.ncbi.nlm.nih.gov/sites/entrez?cmd=search&db=pubmed&term=Appleby%20Paul%5Bau%5D&dispmax=50" target="_blank">Articles by Paul Appleby</a></li> <li class="4 last"><a href="//www.ncbi.nlm.nih.gov/sites/entrez?cmd=search&db=pubmed&term=Peto%20Richard%5Bau%5D&dispmax=50" target="_blank">Articles by Richard Peto</a></li> </ul></div></div><div class="bmj-article-links"><ul class="links"><li class="0 first last"><a href="//portfolio.bmj.com/portfolio/add-to-portfolio.html?t=Dietary%20lipids%20and%20blood%20cholesterol%3A%20quantitative%20meta-analysis%20of%20metabolic%20ward%20studies&u=https%3A//www.bmj.com/content/314/7074/112" target="_blank" id="add-to-bmj-portfolio" class="bmj-portfolio" rel="nofollow">Add article to BMJ Portfolio</a></li> </ul></div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-bmj-minipanel-model-link pane-jnl-bmj-article-button-email-to" > <div class="pane-content"> <div class='minipanel-model-wrapper'><div class='minipanel-model-link-link'><i class="bmj-icon icon-email"></i><a href="/#mini-panel-jnl-bmj-article-button-email-to-1" data-toggle="collapse" role="button" data-font-icon="icon-email">Email to a friend</a></div><div id="mini-panel-jnl-bmj-article-button-email-to-1" class="panel-collapse collapse"><div class="minipanel-header"><h4 class="minipanel-label">Forward this page</h4></div><div class="minipanel-body"><div class="panel-display row bootstrap-onecol" id="mini-panel-jnl_bmj_article_button_email_to"> <div class="panel-panel col-xs-12 col-sm-12 col-md-12 col-lg-12"> <div class="panel-pane pane-block pane-forward-form" > <div class="pane-content"> <form action="/content/314/7074/112" method="post" id="forward-form" accept-charset="UTF-8"><div><div id="edit-instructions" class="form-type-item form-item form-group"> <p>Thank you for your interest in spreading the word about The BMJ.</p><p>NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.</p> </div> <div class="form-type-textfield form-item-name form-item form-group"> <label for="edit-name--2">Username <span class="form-required" title="This field is required.">*</span></label> <input class="form-control form-text required" type="text" id="edit-name--2" name="name" value="" size="58" maxlength="256" /> </div> <div class="form-type-textfield form-item-email form-item form-group"> <label for="edit-email">Your Email <span class="form-required" title="This field is required.">*</span></label> <input class="form-control form-text required" type="text" id="edit-email" name="email" value="" size="58" maxlength="256" /> </div> <div class="form-type-textarea form-item-recipients form-item form-group"> <label for="edit-recipients">Send To <span class="form-required" title="This field is required.">*</span></label> <div class="form-textarea-wrapper"><textarea class="form-control form-textarea required" id="edit-recipients" name="recipients" cols="50" rows="3"></textarea></div> </div> <div id="edit-page" class="form-type-item form-item form-group"> <label for="edit-page">You are going to email the following </label> <a href="/content/314/7074/112" class="active">Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies</a> </div> <div class="form-type-textarea form-item-message form-item form-group"> <label for="edit-message--2">Your Personal Message </label> <div class="form-textarea-wrapper"><textarea class="form-control form-textarea" id="edit-message--2" name="message" cols="50" rows="3"></textarea></div> </div> <input type="hidden" name="path" value="node/522410" /> <input type="hidden" name="path_cid" value="" /> <input type="hidden" name="forward_footer" value=" " /> <input type="hidden" name="form_build_id" value="form-CbS57TmE-DcDgT0uDnnFGY9BsGCyr6wT1-T2lIXiSrM" /> <input type="hidden" name="form_id" value="forward_form" /> <fieldset class="captcha panel panel-default form-wrapper"> <legend class="panel-heading"> <div class="panel-title fieldset-legend"> CAPTCHA </div> </legend> <div class="panel-body"> <p class="help-block"> This question is for testing whether or not you are a human visitor and to prevent automated spam submissions. </p> <input type="hidden" name="captcha_sid" value="383601555" /> <input type="hidden" name="captcha_token" value="43b166249a5ac20c2ef02ae14a883070" /> <input type="hidden" name="captcha_response" value="Google no captcha" /> <div class="g-recaptcha" data-sitekey="6LfnJVIUAAAAAE-bUOMg0MJGki4lqSvDmhJp19fN" data-theme="light" data-type="image"></div> </div> </fieldset> <input class="btn form-submit" type="submit" id="edit-submit--2" name="op" value="Send" /></div></form> </div> </div> </div> </div> </div></div></div> </div> </div> </div> </div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-bmj-article-specialities" > <h2 class="pane-title"> Topics </h2> <div class="pane-content"> <div class="bmj-item-more-less-list bmj-item-list"><ul class="item-list-speciality"><li class="first last"><a href="/specialties/diet" class="article-speciality c-diet">Diet</a></li> </ul></div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-snippet" > <div class="pane-content"> <div class="altmertrics" id="altmertrics"> <div class="snippet-content">  <div id="altmetric"></div>  </div> </div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-snippet" > <div class="pane-content"> <div class="oas-ad-middle-2" id="oas-ad-middle-2"> <div class="snippet-content"> <div id="div-gpt-ad-7326006-3"><script> googletag.cmd.push(function() { googletag.display('div-gpt-ad-7326006-3'); }); </script></div> </div> </div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-custom pane-4" > <div class="pane-content"> <p><a data-target="crossmark"><img src="https://crossmark-cdn.crossref.org/widget/v2.0/logos/CROSSMARK_Color_horizontal.svg" width="150" /></a></p> <div id="crossmark-dialog" style="display: none;" title="Crossmark"> <iframe id="crossmark-dialog-frame" frameborder="0"></iframe></div>  </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-snippet pane-poll-international" id="poll-widget" > <h2 class="pane-title"> This week's poll </h2> <div class="pane-content"> <div class="poll-international" id="poll-international"> <div class="snippet-content"> <p><a class="anchor" id="this-weeks-poll"></a></p> <div id="PDI_container58250" class="PDS_Poll"></div> <div id="PD_superContainer"></div> <div class="poll-related"> <p><a href="https://www.bmj.com/content/385/bmj.q1429">Read</a> related article</p> <p><a href="/about-bmj/poll-archive">See</a> previous polls</p> </div> </div> </div> </div> </div> </aside> </div> </div>  <div class="row"> <div class="panel-panel page-bottom col-md-12 col-lg-12"> <div class="panel-pane pane-highwire-back-to-top" > <div class="pane-content"> <a href="#page" class="back-to-top"><span class="icon-chevron-up"></span> Back to top</a> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-snippet pane-oas-ad-bottom" > <div class="pane-content"> <div class="oas-ad-bottom" id="oas-ad-bottom"> <div class="snippet-content"> <div id="div-gpt-ad-7326006-4"><script> googletag.cmd.push(function() { googletag.display('div-gpt-ad-7326006-4'); }); </script></div> </div> </div> </div> </div> </div> </div>  </div>  </section>  </div> </section> </div> </div>  <div class="footer-wrapper"> <div class="container"> <footer id="footer"> <div class="region region-footer"> <section id="block-panels-mini-bmj-footer" class="block block-panels-mini clearfix"> <div class="panel-display bootstrap-footer" id="mini-panel-bmj_footer"> <div class="footer-top-row"> <div id="footer-social-media" class="footer-column panel-panel col-xs-12 col-sm-3 col-md-3 col-lg-3"> <div class="panel-pane pane-block pane-menu-block-2" > <h2 class="pane-title"> Follow us on </h2> <div class="pane-content"> <div class="menu-block-wrapper menu-block-2 menu-name-menu-footer parent-mlid-1298 menu-level-1"> <ul class="menu nav"><li class="first leaf menu-mlid-1299"><a href="http://twitter.com/bmj_latest" target="_blank">Twitter</a></li> <li class="leaf menu-mlid-1301"><a href="https://www.facebook.com/bmjdotcom" target="_blank">Facebook</a></li> <li class="leaf menu-mlid-1300"><a href="http://youtube.com/user/BMJmedia" target="_blank">YouTube</a></li> <li class="last leaf menu-mlid-1302"><a href="http://feeds.bmj.com/bmj/recent">RSS</a></li> </ul></div> </div> </div> </div> <div class="footer-content col-xs-12 col-sm-9 col-md-9 col-lg-9"> <div id="footer-top-row" class="row"> <div class="footer-column panel-panel col-xs-6 col-sm-4 col-md-4 col-lg-4"> <div class="panel-pane pane-block pane-menu-block-3" > <h2 class="pane-title"> Content links </h2> <div class="pane-content"> <div class="menu-block-wrapper menu-block-3 menu-name-menu-footer parent-mlid-1303 menu-level-1"> <ul class="menu nav"><li class="first leaf menu-mlid-125058"><a href="http://www.bmj.com/collections">Collections</a></li> <li class="leaf menu-mlid-125036"><a href="http://www.bmj.com/health-in-south-asia">Health in South Asia</a></li> <li class="leaf menu-mlid-125034"><a href="http://www.bmj.com/content/women%E2%80%99s-children%E2%80%99s-and-adolescents%E2%80%99-health-0">Women’s, children’s & adolescents’ health</a></li> <li class="leaf menu-mlid-17959"><a href="http://www.bmj.com/freezikaresources">Zika virus</a></li> <li class="leaf menu-mlid-1305"><a href="/us/research">Research</a></li> <li class="leaf menu-mlid-1306"><a href="/us/education">Education</a></li> <li class="leaf menu-mlid-6506"><a href="/us/news">News and views</a></li> <li class="leaf menu-mlid-1310"><a href="http://blogs.bmj.com/bmj/">BMJ Opinion</a></li> <li class="leaf menu-mlid-7612"><a href="/rapid-responses">Rapid responses</a></li> <li class="last leaf menu-mlid-1309"><a href="/archive">Archive</a></li> </ul></div> </div> </div> </div> <div class="footer-column panel-panel col-xs-6 col-sm-4 col-md-4 col-lg-4"> <div class="panel-pane pane-block pane-menu-block-4" > <h2 class="pane-title"> About us </h2> <div class="pane-content"> <div class="menu-block-wrapper menu-block-4 menu-name-menu-footer parent-mlid-1314 menu-level-1"> <ul class="menu nav"><li class="first leaf menu-mlid-6487"><a href="/about-bmj">About us</a></li> <li class="leaf menu-mlid-1316"><a href="/about-bmj/editorial-staff">Editorial staff</a></li> <li class="leaf menu-mlid-1317"><a href="/about-bmj/editorial-staff/bmj-united-states">BMJ in the USA</a></li> <li class="leaf menu-mlid-127585"><a href="/health-in-latin-america">BMJ in Latin America</a></li> <li class="leaf menu-mlid-1318"><a href="/about-bmj/editorial-staff/bmj-south-asia">BMJ in South Asia</a></li> <li class="leaf menu-mlid-1319"><a href="/about-bmj/advisory-panels">Advisers</a></li> <li class="leaf menu-mlid-1320"><a href="/about-bmj/resources-authors/forms-policies-and-checklists">Policies</a></li> <li class="last leaf menu-mlid-1323"><a href="http://mc.manuscriptcentral.com/bmj">Submit your paper</a></li> </ul></div> </div> </div> </div> <div class="footer-column panel-panel col-xs-6 col-sm-4 col-md-4 col-lg-4"> <div class="panel-pane pane-block pane-menu-block-5" > <h2 class="pane-title"> Resources </h2> <div class="pane-content"> <div class="menu-block-wrapper menu-block-5 menu-name-menu-footer parent-mlid-1324 menu-level-1"> <ul class="menu nav"><li class="first leaf menu-mlid-1325"><a href="/about-bmj/resources-authors">Authors</a></li> <li class="leaf menu-mlid-1326"><a href="/about-bmj/resources-reviewers">Reviewers</a></li> <li class="leaf menu-mlid-1327"><a href="/about-bmj/resources-bma-members">BMA members</a></li> <li class="leaf menu-mlid-1329"><a href="/about-bmj/resources-readers">Readers</a></li> <li class="leaf menu-mlid-1328"><a href="/about-bmj/resources-subscribers">Subscribers</a></li> <li class="leaf menu-mlid-1330"><a href="/about-bmj/resources-advertisers-and-sponsors">Advertisers and sponsors</a></li> <li class="leaf menu-mlid-1331"><a href="/about-bmj/resources-media">Media</a></li> <li class="last leaf menu-mlid-7610"><a href="https://recruiter.bmj.com/">Recruiters</a></li> </ul></div> </div> </div> </div> <div class="footer-column panel-panel col-xs-6 col-sm-4 col-md-4 col-lg-4"> <div class="panel-pane pane-block pane-menu-block-6" > <h2 class="pane-title"> Explore BMJ </h2> <div class="pane-content"> <div class="menu-block-wrapper menu-block-6 menu-name-menu-footer parent-mlid-1332 menu-level-1"> <ul class="menu nav"><li class="first leaf menu-mlid-7613"><a href="https://www.bmj.com/company/?int_source=tbmj&int_medium=footer&int_campaign=URLswitch">Our company</a></li> <li class="leaf menu-mlid-7421"><a href="https://jobs.bmj.com/">BMJ Careers</a></li> <li class="leaf menu-mlid-7423"><a href="http://learning.bmj.com/">BMJ Learning</a></li> <li class="leaf menu-mlid-7424"><a href="http://masterclasses.bmj.com">BMJ Masterclasses</a></li> <li class="leaf menu-mlid-7425"><a href="http://journals.bmj.com">BMJ Journals</a></li> <li class="leaf menu-mlid-7422"><a href="/student">BMJ Student</a></li> <li class="leaf menu-mlid-7426"><a href="http://www.bmj.com/about-bmj/resources-readers">Academic edition of The BMJ</a></li> <li class="leaf menu-mlid-7427"><a href="http://bestpractice.bmj.com/">BMJ Best Practice</a></li> <li class="last leaf menu-mlid-17958"><a href="http://thebmjawards.bmj.com/home">The BMJ Awards</a></li> </ul></div> </div> </div> </div> <div class="footer-column panel-panel col-xs-6 col-sm-4 col-md-4 col-lg-4"> <div class="panel-pane pane-block pane-menu-block-7" > <h2 class="pane-title"> My account </h2> <div class="pane-content"> <div class="menu-block-wrapper menu-block-7 menu-name-menu-footer parent-mlid-1343 menu-level-1"> <ul class="menu nav"><li class="first leaf menu-mlid-1344"><a href="http://myaccount.bmj.com/myaccount/account/hw-registration.html">Email alerts</a></li> <li class="last leaf menu-mlid-1345"><a href="http://journals.bmj.com/cgi/activate">Activate subscription</a></li> </ul></div> </div> </div> </div> <div class="footer-column panel-panel col-xs-6 col-sm-4 col-md-4 col-lg-4"> <div class="panel-pane pane-block pane-menu-block-8" > <h2 class="pane-title"> Information </h2> <div class="pane-content"> <div class="menu-block-wrapper menu-block-8 menu-name-menu-footer parent-mlid-1346 menu-level-1"> <ul class="menu nav"><li class="first leaf menu-mlid-1347"><a href="/about-bmj/contact-us">Contact us</a></li> <li class="last leaf menu-mlid-1321"><a href="/about-bmj/complaints-procedure">Complaints</a></li> </ul></div> </div> </div> </div> </div> </div> </div> <div id="footer-bottom-row" class="row"> <div class="panel-panel col-xs-12 col-sm-12 col-md-12 col-lg-12"> <div class="panel-pane pane-block pane-menu-block-9 hidden-phone" > <div class="pane-content"> <div class="menu-block-wrapper menu-block-9 menu-name-menu-footer parent-mlid-1349 menu-level-1"> <ul class="menu nav"><li class="first leaf menu-mlid-125888"><a id="ot-sdk-btn" class="ot-sdk-show-settings" clickable="false">Cookie settings</a></li> <li class="leaf menu-mlid-1350"><a href="https://www.bmj.com/company/your-privacy/cookies-policy/">Cookie Policy</a></li> <li class="leaf menu-mlid-125299"><a href="https://www.bmj.com/company/your-privacy/">Privacy policy</a></li> <li class="leaf menu-mlid-1351"><a href="http://www.bmj.com/company/legal-information/">Website T&Cs</a></li> <li class="leaf menu-mlid-1352"><a href="http://group.bmj.com/group/about/revenue-sources">Revenue Sources</a></li> <li class="leaf menu-mlid-1353"><a href="http://home.highwire.org/">HighWire Press</a></li> <li class="last leaf menu-mlid-8093"><a href="/sitemap">Sitemap</a></li> </ul></div> </div> </div> <div class="panel-separator"></div><div class="panel-pane pane-bmj-copy-right" > <div class="pane-content"> <div class="copyright">Copyright © 2025 BMJ Publishing Group Ltd</div> </div> </div> </div> </div> </div> </section>  </div> </footer>  </div> </div> </div>  </div>  <script src="https://www.bmj.com/sites/default/files/advagg_js/js__uW7NyUocxI-7E_sL-GP7L5FYvHrfi0D8UkwaFa_jFUQ__ITpTmydBN18ujP4Nq9igNKs2_uPvSa_MMIGZilNH7xo__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.js"></script> <script src="https://www.bmj.com/sites/default/files/advagg_js/js__L2RNsEq1_BwrvVr4-XqL6HCM3TrId8FewyOD-ifl56Y__xFUWwD-CmrvIMpj7PKKOzG6M0u5x4a4YsfZcc7fa3qg__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.js"></script> <script src="https://www.bmj.com/sites/default/files/advagg_js/js__ADNpAJRqEZQTdJr17qFcuXkfatW9ULGGExiAh_zWtxs__Xan4DQzBMVgws81Yi1i-_1Amp0wkg5IKAA2fCWPVSwI__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.js"></script> <script src="https://www.bmj.com/sites/default/files/advagg_js/js__wteGLiD1wamodYGt1CPf350dgG_dnSPaybjTJJ4V8O0__tHSi0oVxXVY1K8dKSadgniknKfq0JO39EkwFnl-Qx3k__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.js"></script> <script src="https://static.polldaddy.com/w/58250.js"></script> <script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.7/jquery-ui.min.js"></script> <script src="https://crossmark-cdn.crossref.org/widget/v2.0/widget.js"></script> <script src="https://d1bxh8uas1mnw7.cloudfront.net/assets/embed.js"></script> <script src="https://www.bmj.com/sites/default/files/advagg_js/js__SFoHIUTheqo0e4hxRINC0gFp_rO4LFMUUrC70xvOwtY__h5zRuwNt-m_fFPTyMKF2APwK7ArnJ2U3S4dW5Cp_p_o__a7Jq5VSqcMKMeR_gboGw1x4AC4g6SRpO1Geb_4xJjYc.js"></script> <script> setTimeout(function(){var a=document.createElement("script"); var b=document.getElementsByTagName("script")[0]; a.src=document.location.protocol+"//dnn506yrbagrg.cloudfront.net/pages/scripts/0014/4896.js?"+Math.floor(new Date().getTime()/3600000); a.async=true;a.type="text/javascript";b.parentNode.insertBefore(a,b)}, 1);</script> <script>jQuery(".page-search .pane-quick-search-results .search-snippet").text(function (_, old){ return old.replace(/\S+@\S+\.\S+/, "");});</script> <script type="text/javascript"> /* <![CDATA[ */ var google_conversion_id = 973817434; var google_custom_params = window.google_tag_params; var google_remarketing_only = true; /* ]]> */ </script> <script type="text/javascript" src="//www.googleadservices.com/pagead/conversion.js"> </script> <noscript> <div style="display:inline;"> <img height="1" width="1" style="border-style:none;" alt="" src="//googleads.g.doubleclick.net/pagead/viewthroughconversion/973817434/?value=0&guid=ON&script=0"/> </div> </noscript> <script async src="https://cdn.pbgrd.com/core-bmj.js"></script> </body> </html>