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The effect of replacing saturated fat with mostly n-6 polyunsaturated fat on coronary heart disease: a meta-analysis of randomised controlled trials.

Published on Dec 1, 2017in Nutrition Journal 3.57
· DOI :10.1186/s12937-017-0254-5
Steven Hamley5
Estimated H-index: 5
(Deakin University)
Abstract
A cornerstone of conventional dietary advice is the recommendation to replace saturated fatty acids (SFA) with mostly n-6 polyunsaturated fatty acids (PUFA) to reduce the risk of coronary heart disease (CHD). Many clinical trials aimed to test this advice and have had their results pooled in several meta-analyses. However, earlier meta-analyses did not sufficiently account for major confounding variables that were present in some of those trials. Therefore, the aim of the study was to account for the major confounding variables in the diet heart trials, and emphasise the results from those trials that most accurately test the effect of replacing SFA with mostly n-6 PUFA. Clinical trials were identified from earlier meta-analyses. Relevant trials were categorised as ‘adequately controlled’ or ‘inadequately controlled’ depending on whether there were substantial dietary or non-dietary differences between the experimental and control groups that were not related to SFA or mostly n-6 PUFA intake, then were subject to different subgroup analyses. When pooling results from only the adequately controlled trials there was no effect for major CHD events (RR = 1.06, CI = 0.86–1.31), total CHD events (RR = 1.02, CI = 0.84–1.23), CHD mortality (RR = 1.13, CI = 0.91–1.40) and total mortality (RR = 1.07, CI = 0.90–1.26). Whereas, the pooled results from all trials, including the inadequately controlled trials, suggested that replacing SFA with mostly n-6 PUFA would significantly reduce the risk of total CHD events (RR = 0.80, CI = 0.65–0.98, P = 0.03), but not major CHD events (RR = 0.87, CI = 0.70–1.07), CHD mortality (RR = 0.90, CI = 0.70–1.17) and total mortality (RR = 1.00, CI = 0.90–1.10). Available evidence from adequately controlled randomised controlled trials suggest replacing SFA with mostly n-6 PUFA is unlikely to reduce CHD events, CHD mortality or total mortality. The suggestion of benefits reported in earlier meta-analyses is due to the inclusion of inadequately controlled trials. These findings have implications for current dietary recommendations.
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References81
Newest
Published on Apr 12, 2016in BMJ 23.56
Christopher E. Ramsden16
Estimated H-index: 16
(UNC: University of North Carolina at Chapel Hill),
Daisy Zamora11
Estimated H-index: 11
(UNC: University of North Carolina at Chapel Hill)
+ 7 AuthorsJoseph R. Hibbeln46
Estimated H-index: 46
(NIH: National Institutes of Health)
Objective To examine the traditional diet-heart hypothesis through recovery and analysis of previously unpublished data from the Minnesota Coronary Experiment (MCE) and to put findings in the context of existing diet-heart randomized controlled trials through a systematic review and meta-analysis. Design The MCE (1968-73) is a double blind randomized controlled trial designed to test whether replacement of saturated fat with vegetable oil rich in linoleic acid reduces coronary heart disease and ...
114 Citations Source Cite
Published on Nov 1, 2015in Nutrition Metabolism and Cardiovascular Diseases 3.32
J. N. Kiage1
Estimated H-index: 1
(VUMC: Vanderbilt University Medical Center),
Uchechukwu Sampson34
Estimated H-index: 34
+ 8 AuthorsWilliam J. Blot95
Estimated H-index: 95
(VUMC: Vanderbilt University Medical Center)
Abstract Background and aims Consumption of polyunsaturated fatty acids (PUFA), especially the n3-series, may protect against cardiovascular disease (CVD), but recent randomized studies have failed to demonstrate these benefits. One of the prevailing hypotheses is that PUFA intake may not confer benefits beyond those provided by statins, but studies comparing statin users to non-users with regard to effects of PUFA are lacking. Methods and results Black and white men and women (n = 69,559) in th...
8 Citations Source Cite
Published on Aug 11, 2015in BMJ 23.56
Russell J. de Souza35
Estimated H-index: 35
,
Andrew Mente30
Estimated H-index: 30
(McMaster University)
+ 8 AuthorsJoseph Beyene61
Estimated H-index: 61
(McMaster University)
Objective To systematically review associations between intake of saturated fat and trans unsaturated fat and all cause mortality, cardiovascular disease (CVD) and associated mortality, coronary heart disease (CHD) and associated mortality, ischemic stroke, and type 2 diabetes. Design Systematic review and meta-analysis. Data sources Medline, Embase, Cochrane Central Registry of Controlled Trials, Evidence-Based Medicine Reviews, and CINAHL from inception to 1 May 2015, supplemented by bibliogra...
336 Citations Source Cite
Published on Jul 1, 2015in The American Journal of Clinical Nutrition 6.55
Katerina Vafeiadou19
Estimated H-index: 19
,
Michelle Weech5
Estimated H-index: 5
+ 4 AuthorsJulie A. Lovegrove42
Estimated H-index: 42
Public health strategies to lower cardiovascular disease (CVD) risk involve reducing dietary saturated fatty acid (SFA) intake to ≤10% of total energy (%TE). However, the optimal type of replacement fat is unclear.We investigated the substitution of 9.5-9.6%TE dietary SFAs with either monounsaturated fatty acids (MUFAs) or n-6 (ω-6) polyunsaturated fatty acids (PUFAs) on vascular function and other CVD risk factors.In a randomized, controlled, single-blind, parallel-group dietary intervention, 1...
57 Citations Source Cite
Published on Jun 10, 2015in Cochrane Database of Systematic Reviews 6.75
Lee Hooper51
Estimated H-index: 51
(UEA: University of East Anglia),
Nicole Martin7
Estimated H-index: 7
(Lond: University of London)
+ 1 AuthorsGeorge Davey-Smith177
Estimated H-index: 177
(UoB: University of Bristol)
Background Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally it is unclear whether the energy from saturated fats that are lost in the diet are more helpfully replaced by polyunsaturated fats, monounsaturated fats, carbohydrate or protein. This review is part of a series split from and updating an overarching review. Objectives To assess the effect of reducing saturated fat intake and replacing it with carbohydrate (CHO),...
138 Citations Source Cite
Published on Jan 1, 2015
Zoë Harcombe7
Estimated H-index: 7
(University of the West of Scotland),
Julien S. Baker21
Estimated H-index: 21
(University of the West of Scotland)
+ 4 AuthorsFergal M. Grace17
Estimated H-index: 17
(University of the West of Scotland)
Objectives: National dietary guidelines were introduced in 1977 and 1983, by the US and UK governments, respectively, with the ambition of reducing coronary heart disease (CHD) by reducing fat intake. To date, no analysis of the evidence base for these recommendations has been undertaken. The present study examines the evidence from randomised controlled trials (RCTs) available to the US and UK regulatory committees at their respective points of implementation. Methods: A systematic review and m...
75 Citations Source Cite
Published on Oct 28, 2014in Circulation 18.88
Maryam Sadat Farvid1
Estimated H-index: 1
(Shahid Beheshti University of Medical Sciences and Health Services),
Ming Ding10
Estimated H-index: 10
(Harvard University)
+ 5 AuthorsFrank B. Hu202
Estimated H-index: 202
(Harvard University)
Background—Previous studies on intake of linoleic acid (LA), the predominant n-6 fatty acid, and coronary heart disease (CHD) risk have generated inconsistent results. We performed a systematic review and meta-analysis of prospective cohort studies to summarize the evidence regarding the relation of dietary LA intake and CHD risk. Methods and Results—We searched MEDLINE and EMBASE databases through June 2013 for prospective cohort studies that reported the association between dietary LA and CHD ...
179 Citations Source Cite
Published on Jul 18, 2014in BMJ 23.56
Daniel Keene3
Estimated H-index: 3
(NIH: National Institutes of Health),
Clare F. Price1
Estimated H-index: 1
(NIH: National Institutes of Health)
+ 1 AuthorsDarrel P. Francis52
Estimated H-index: 52
(NIH: National Institutes of Health)
Objective To investigate the effects on cardiovascular outcomes of drug interventions that increase high density lipoprotein levels. Design Meta-analysis. Studies reviewed Therapeutic benefit of niacin, fibrates, and cholesteryl ester transfer protein (CETP) inhibitors on cardiovascular events (all cause mortality, coronary heart disease mortality, non-fatal myocardial infarction, and stroke). Results 117 411 patients were randomised in a total of 39 trials. All interventions increased the level...
197 Citations Source Cite
Published on Apr 1, 2014in BMJ Open 2.41
Lukas Schwingshackl30
Estimated H-index: 30
(University of Vienna),
Georg F. Hoffmann63
Estimated H-index: 63
(University of Vienna)
Objective: Previous systematic reviews were not restricted to either primary or secondary prevention trials, this study aimed to investigate the effects of reduced and/or modified fat diets and dietary fatty acids on all-cause mortality, cardiovascular mortality and cardiovascular events in participants with established coronary heart disease. Design: Systematic review, meta-analysis and univariate/multivariate meta-regression. Eligibility and criteria for selecting studies: Electronic searches ...
42 Citations Source Cite
Published on Mar 18, 2014in Annals of Internal Medicine 19.38
Rajiv Chowdhury47
Estimated H-index: 47
,
Samantha Warnakula9
Estimated H-index: 9
+ 11 AuthorsSimon G. Thompson95
Estimated H-index: 95
Primary Funding Source: British Heart Foundation, Medical Research Council, Cambridge National Institute for Health Research Biomedical Research Centre, and Gates Cambridge.
606 Citations Source Cite
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Published on Apr 6, 2019in Nutrients 4.20
Simon Rønnow Schacht , Mads Vendelbo Lind7
Estimated H-index: 7
+ 7 AuthorsInge Tetens37
Estimated H-index: 37
Suboptimal intake of nutrients is associated with adverse health outcomes. The current study investigated the risk of suboptimal macro and micronutrient intake and their potential determinants in a cross-sectional study of community-dwelling older Danish adults (65–81 years). Nutrient intake was obtained through a 3-day weighted dietary record and information on personal characteristics and attitudes towards specific foods and dietary habits and nutrition through questionnaires. Dietary Referenc...
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Published on Apr 1, 2019in European Journal of Epidemiology 7.02
John P. A. Ioannidis147
Estimated H-index: 147
(Stanford University)
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Published on Jan 1, 2019in European Journal of Lipid Science and Technology 2.20
Dipak Purshottam Ramji29
Estimated H-index: 29
(Cardiff University)
Atherosclerosis and its complications are responsible for more global deaths than any other disease. Atherosclerosis is a chronic inflammatory disease of medium and large arteries that can cause clinical complications such as myocardial infarction and cerebrovascular accidents. Current therapies against atherosclerosis mainly target the dyslipidemia associated with the disease and are associated with considerable residual risk for cardiovascular disease together with various side effects. In add...
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Published on Dec 4, 2018in Nutrients 4.20
Emmanouil Korakas1
Estimated H-index: 1
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George Dimitriadis27
Estimated H-index: 27
+ 1 AuthorsVaia Lambadiari16
Estimated H-index: 16
The role of nutrition in the pathogenesis of cardiovascular disease has long been debated. The established notion of the deleterious effects of fat is recently under question, with numerous studies demonstrating the benefits of low-carbohydrate, high-fat diets in terms of obesity, diabetes, dyslipidemia, and metabolic derangement. Monounsaturated and polyunsaturated fatty acids, especially n-3 PUFAs (polyunsaturated fatty acids), are the types of fat that favor metabolic markers and are key comp...
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Published on Nov 15, 2018
Penny M. Kris-Etherton88
Estimated H-index: 88
(PSU: Pennsylvania State University),
Kristina S. Petersen9
Estimated H-index: 9
(PSU: Pennsylvania State University),
Linda Van Horn72
Estimated H-index: 72
(NU: Northwestern University)
Treatment guidelines and population-based recommendations evolve from research vetted by the scientific community. Healthcare providers require practice guidelines resulting from rigorous review of the totality of evidence. Open discussion/debate among experts is fundamental and encouraged, but blatant disregard for scientific process can lead to confusion and public distrust. A recent example is the controversy among scientists, healthcare professionals and the public about dietary saturated fa...
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Elena Fattore22
Estimated H-index: 22
,
Elena Massa1
Estimated H-index: 1
AbstractThis narrative review summarises the main studies of the role of the different fatty acids in coronary heart disease (CHD) and cardiovascular disease (CVD) risk and the current scientific debate on dietary recommendations. Reduction and substitution of the saturated fatty acids (SFAs) with the polyunsaturated fatty acids (PUFAs) are still the main dietary recommendation to prevent CHD and CVD. In the last few years, however, the strength of the scientific evidence underlying this dietary...
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Published on Oct 23, 2018in PLOS ONE 2.77
Krishna Bahadur Kc4
Estimated H-index: 4
(U of G: University of Guelph),
Goretty Dias11
Estimated H-index: 11
(UW: University of Waterloo)
+ 18 AuthorsKari E. Dunfield15
Estimated H-index: 15
(U of G: University of Guelph)
Sustainably feeding the next generation is often described as one of the most pressing “grand challenges” facing the 21st century. Generally, scholars propose addressing this problem by increasing agricultural production, investing in technology to boost yields, changing diets, or reducing food waste. In this paper, we explore whether global food production is nutritionally balanced by comparing the diet that nutritionists recommend versus global agricultural production statistics. Results show ...
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