{"url":"https://whatshealthyandwhy.com/saturated-fat/is-saturated-fat-bad-for-your-heart","path":"/saturated-fat/is-saturated-fat-bad-for-your-heart","alternates":{"json":"https://whatshealthyandwhy.com/api/articles/saturated-fat/is-saturated-fat-bad-for-your-heart.json","markdown":"https://whatshealthyandwhy.com/saturated-fat/is-saturated-fat-bad-for-your-heart.md"},"topic":{"slug":"saturated-fat","name":"Saturated Fat","url":"https://whatshealthyandwhy.com/saturated-fat"},"slug":"is-saturated-fat-bad-for-your-heart","order":1,"title":"Is Saturated Fat Really Bad for Your Heart?","question":"Is saturated fat really bad for your heart?","answer":"Cutting saturated fat likely lowers heart risk modestly, but only if unsaturated fats or whole grains take its place, not refined carbs.","description":"What trials and large cohorts say about saturated fat and heart disease, why the replacement food matters, and how dairy, meat, butter and coconut oil fit.","confidence":3,"confidenceNote":"Trials show a modest drop in cardiovascular events when saturated fat is cut, but deaths did not clearly change, cohorts are mixed, and replacement and food source change the answer.","evidenceSummary":{"rctCount":1,"observationalCount":3,"metaAnalysisCount":5,"totalParticipants":"56,675 (trials); 344,696 (pooled cohorts)","replicated":false,"newestStudyYear":2020},"category":{"categoryTitle":"What's Good For You","categorySlug":"good-for-you","subcategoryName":"Foods & Drinks","subcategorySlug":"foods","url":"https://whatshealthyandwhy.com/explore/good-for-you/foods"},"actions":["Swap some saturated fat for olive oil, nuts, seeds or fish, not white bread or sugar: replacing 5% of calories with polyunsaturated fat meant 13–25% fewer coronary events [4][5].","Judge foods, not nutrients: whole-fat dairy and dark chocolate show no harm from their saturated fat [3], but coconut oil raised LDL about 10 mg/dL over other plant oils [6].","If LDL is high, ask your clinician about your LDL or apoB and treatment: lowering LDL by almost any means lowers risk proportionally, diet is one tool of several [7]."],"cautions":["If you cut saturated fat, do not fill the gap with refined starch or sugar. Replacing it with those did not lower heart risk in cohorts or trials [2][5].","Inherited conditions such as familial hypercholesterolemia raise LDL and heart risk whatever you eat. Follow your cardiologist's plan [7]."],"simpleText":"Cutting saturated fat probably lowers heart risk a little, but what you put in its place decides the result. In trials, cutting it reduced combined heart and stroke events by about 17% over several years, with no clear change in deaths [1]. Swapping it for polyunsaturated fat helped, while swapping it for refined carbohydrates did not [2]. Whole foods such as dairy may not behave like the nutrient [3].","mediumText":"How it works\n\nSaturated fat is the fat that stays solid at room temperature, found in butter, cheese, fatty meat, and coconut and palm oils. Its best-established effect is on LDL cholesterol. LDL is a proven cause of atherosclerosis, based on genetic, cohort and trial data covering more than two million people [7]. Cutting saturated fat modestly lowers LDL [1].\n\nThe trials. Fifteen trials lasting at least two years (56,675 people) found that cutting saturated fat reduced cardiovascular events by 17% (risk ratio 0.83). Bigger cuts in saturated fat gave bigger benefits, and about 56 people needed to cut it for four years to prevent one event. Total deaths did not change clearly [1]. In eight trials, replacing saturated fat with polyunsaturated vegetable oil lowered coronary events by 19% [8].\n\nWhy cohorts look neutral. Pooled cohort analyses found saturated fat intake by itself was not linked to heart disease or death [9][10], and in 18 countries (PURE) higher intake went with lower stroke and death rates [11]. The catch is \"compared with what?\" In two large US cohorts, replacing 5% of calories from saturated fat with polyunsaturated fat went with 25% lower coronary risk, with monounsaturated fat 15% and with whole grains 9%. Replacing it with refined starch and sugar showed no benefit [5].\n\nFood matters. One review argues whole-fat dairy, unprocessed meat and dark chocolate are not linked to higher cardiovascular risk [3]. Coconut oil, by contrast, raised LDL by 10.5 mg/dL in 16 trials compared with nontropical oils [6]. Our articles on dairy, red meat and coconut oil go further.\n\nThe counter-case. When the old Minnesota Coronary Experiment data were recovered, a corn-oil diet lowered cholesterol but did not reduce deaths [12]. That is part of why polyunsaturated oils are debated, including in our seed oils articles.","deepText":"The evidence in detail\n\nRandomized trials. The Cochrane review (15 trials, 56,675 participants, at least 24 months) found a risk ratio of 0.83 (95% CI 0.70 to 0.98) for combined cardiovascular events with moderate-quality evidence, and greater cuts in saturated fat gave greater benefits. It found little or no effect on all-cause mortality (0.96, 0.90 to 1.03) or cardiovascular mortality (0.95, 0.80 to 1.12). The number needed to treat was 56 in primary prevention. Subgroups showed no clear difference between replacing saturated fat with polyunsaturated fat or carbohydrate, though data on monounsaturated fat were sparse. The first 2020 version reported a 21% reduction; the revised August 2020 version cited here reports 17% [1]. Mozaffarian and colleagues pooled eight trials (13,614 people, 1,042 coronary events) that increased polyunsaturated fat to 14.9% of energy versus 5.0%, and found a 19% reduction (risk ratio 0.81, 0.70 to 0.95) [8]. The American Heart Association advisory judged the evidence strong enough to conclude lowering saturated fat in favor of unsaturated fats will lower cardiovascular disease, citing a reduction of about 30% in trials [2].\n\nCohorts and pooled analyses. Siri-Tarino and colleagues pooled 21 cohorts (347,747 people) and found relative risks of 1.07 for coronary disease (0.96 to 1.19), 0.81 for stroke and 1.00 for cardiovascular disease, none significant [9]. De Souza's meta-analysis gave 0.99 for all-cause mortality, 0.97 for cardiovascular mortality and 1.06 for total coronary disease, with certainty rated very low [10]. PURE followed 135,335 adults for 7.4 years: the top fifth of saturated fat intake had a hazard ratio of 0.86 for death and 0.79 for stroke compared with the bottom fifth, and no difference for heart attack, while high carbohydrate intake went with higher mortality (1.28). Diets differ greatly across those 18 countries, and the authors argued guidelines be reconsidered [11]. Replacement analyses help reconcile this: a pooled analysis of 11 cohorts (344,696 people) found that replacing 5% of energy from saturated fat with polyunsaturated fat gave a hazard ratio of 0.87 for coronary events, while replacing it with carbohydrate gave 1.07 [4], and the Nurses' Health and Health Professionals cohorts (127,536 people, 24 to 30 years, 7,667 events) gave 0.75 for polyunsaturated fat and no benefit from refined carbohydrates [5].\n\nThe contradicting trials. In the Minnesota Coronary Experiment (9,423 residents of nursing and mental hospitals), a diet swapping saturated fat for corn oil lowered cholesterol by 13.8% against 1.0% but did not reduce mortality, and mortality rose with greater cholesterol reduction (hazard ratio 1.22 per 30 mg/dL). A meta-analysis of five such trials (10,808 people) found no benefit for coronary death (1.13, 0.83 to 1.54) or all-cause mortality (1.07, 0.90 to 1.27) [12]. The authors argue incomplete publication inflated earlier estimates; participants lived in institutions, which may limit how far the results generalize.\n\nLDL and food sources. The European Atherosclerosis Society consensus concluded that LDL causes atherosclerotic disease, and that benefit scales with the size and duration of the LDL reduction [7]. Astrup and colleagues argue that saturated fat raises mostly large, less harmful LDL particles and that whole foods differ from nutrients, so dairy, unprocessed meat and dark chocolate need not be limited; their conclusion contradicts the AHA advisory [3]. A coconut oil meta-analysis (16 trials) found LDL up 10.47 mg/dL (95% CI 3.01 to 17.94) and HDL up 4.00 mg/dL, with no effect on glycemia, inflammation or adiposity [6].\n\nBottom line (confidence 3 of 5). Lowering saturated fat probably gives a modest cut in heart events when unsaturated fat or whole grains replace it, but not in deaths, and not when refined carbs replace it. Cohort data are neutral and food source matters, so treat the nutrient as one input among many.","deepTruncated":false,"references":[{"id":"1","title":"Reduction in saturated fat intake for cardiovascular disease","authors":"Hooper L, Martin N, Jimoh OF, et al.","year":2020,"journal":"Cochrane Database Syst Rev","pmid":"32827219","url":"https://pubmed.ncbi.nlm.nih.gov/32827219/"},{"id":"2","title":"Dietary Fats and Cardiovascular Disease: A Presidential Advisory From the American Heart Association","authors":"Sacks FM, Lichtenstein AH, Wu JHY, et al.","year":2017,"journal":"Circulation","pmid":"28620111","url":"https://pubmed.ncbi.nlm.nih.gov/28620111/"},{"id":"3","title":"Saturated Fats and Health: A Reassessment and Proposal for Food-Based Recommendations: JACC State-of-the-Art Review","authors":"Astrup A, Magkos F, Bier DM, et al.","year":2020,"journal":"J Am Coll Cardiol","pmid":"32562735","url":"https://pubmed.ncbi.nlm.nih.gov/32562735/"},{"id":"4","title":"Major types of dietary fat and risk of coronary heart disease: a pooled analysis of 11 cohort studies","authors":"Jakobsen MU, O'Reilly EJ, Heitmann BL, et al.","year":2009,"journal":"Am J Clin Nutr","pmid":"19211817","url":"https://pubmed.ncbi.nlm.nih.gov/19211817/"},{"id":"5","title":"Saturated Fats Compared With Unsaturated Fats and Sources of Carbohydrates in Relation to Risk of Coronary Heart Disease: A Prospective Cohort Study","authors":"Li Y, Hruby A, Bernstein AM, et al.","year":2015,"journal":"J Am Coll Cardiol","pmid":"26429077","url":"https://pubmed.ncbi.nlm.nih.gov/26429077/"},{"id":"6","title":"The Effect of Coconut Oil Consumption on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Clinical Trials","authors":"Neelakantan N, Seah JYH, van Dam RM","year":2020,"journal":"Circulation","pmid":"31928080","url":"https://pubmed.ncbi.nlm.nih.gov/31928080/"},{"id":"7","title":"Low-density lipoproteins cause atherosclerotic cardiovascular disease. 1. Evidence from genetic, epidemiologic, and clinical studies. A consensus statement from the European Atherosclerosis Society Consensus Panel","authors":"Ference BA, Ginsberg HN, Graham I, et al.","year":2017,"journal":"Eur Heart J","pmid":"28444290","url":"https://pubmed.ncbi.nlm.nih.gov/28444290/"},{"id":"8","title":"Effects on coronary heart disease of increasing polyunsaturated fat in place of saturated fat: a systematic review and meta-analysis of randomized controlled trials","authors":"Mozaffarian D, Micha R, Wallace S","year":2010,"journal":"PLoS Med","pmid":"20351774","url":"https://pubmed.ncbi.nlm.nih.gov/20351774/"},{"id":"9","title":"Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease","authors":"Siri-Tarino PW, Sun Q, Hu FB, et al.","year":2010,"journal":"Am J Clin Nutr","pmid":"20071648","url":"https://pubmed.ncbi.nlm.nih.gov/20071648/"},{"id":"10","title":"Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies","authors":"de Souza RJ, Mente A, Maroleanu A, et al.","year":2015,"journal":"BMJ","pmid":"26268692","url":"https://pubmed.ncbi.nlm.nih.gov/26268692/"},{"id":"11","title":"Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study","authors":"Dehghan M, Mente A, Zhang X, et al.","year":2017,"journal":"Lancet","pmid":"28864332","url":"https://pubmed.ncbi.nlm.nih.gov/28864332/"},{"id":"12","title":"Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73)","authors":"Ramsden CE, Zamora D, Majchrzak-Hong S, et al.","year":2016,"journal":"BMJ","pmid":"27071971","url":"https://pubmed.ncbi.nlm.nih.gov/27071971/"}],"wordCount":981,"source":{"path":"src/content/topics/saturated-fat/is-saturated-fat-bad-for-your-heart.md"},"citeAs":"“Is saturated fat really bad for your heart?.” What's Healthy and Why. https://whatshealthyandwhy.com/saturated-fat/is-saturated-fat-bad-for-your-heart","notice":"General information backed by peer-reviewed research, not medical advice."}