Numerous population-based studies have found higher intakes of fish/seafood containing long-chain omega-3 fatty acids as eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) have been associated with considerably lower mortality rates from coronary heart disease (CHD) and stroke.1 Several meta-analyses, which involve the combining of results from multiple human studies, have reported that supplementation with EPA/DHA can reduce the risk of coronary death by approximately 10 to 30 percent.2 The benefits of such omega-3 fatty acid supplementation over periods of up to five years (often in the range of 900 to 3,000 mg of EPA/DHA daily) against myocardial infarction and cardiac death appear to be particularly evident in those with a history of cardiovascular disease (CVD).3 Further, a progressively lower risk of heart failure over an average follow-up period of 13 years has been related to increased intakes of EPA/DHA (approaching 700 mg/d).4
There is evidence that the short-chain omega-3 fatty acid (alpha-linolenic acid [ALA]) from selected plant sources may reduce the CHD risk in those with low intakes of EPA/DHA (below 100 mg/d).5 Essentially all population and clinical studies which have supported the cardiovascular health benefits of increased intakes of EPA/DHA have been conducted in those subjects/patients who were consuming regular diets with significant amounts of ALA. Since higher intakes of omega-3 fatty acids from fish/seafood and oral supplements predictably result in higher circulating levels of EPA/DHA, it is not surprising that elevated blood levels of long-chain omega-3 fatty acids have been inversely associated with the risk of sudden death.6
For the general healthy adult population, daily target intakes of EPA plus DHA of at least 500 mg/d for the prevention of cardiovascular disease (CVD) have been recommended by various organizations (dietetic associations in the United States and Canada, the Global Organization for EPA and DHA Omega-3s [GOED] and the International Society for the Study of Fatty Acids and Lipids [ISSFAL]) with higher targets often set globally for secondary prevention in those with pre-existing CVD. It is noteworthy that current intakes of EPA plus DHA in North America (which average only 120 to 150 mg/person/d) and in numerous other countries worldwide fall well short of the targets, thereby resulting in a wide “nutrition gap.” A recent European study found the risk for fatal CHD was 46 percent lower and for sudden cardiac death was 51 percent lower over a follow-up interval of six years in subjects (average age of 67 years and initially fe of prior CVD) who met or surpassed the recommended daily intake for EPA/DHA of 500 mg/d as compared to those who fell below the target.7
Learn more about the role omega-3s play in heart health in INSIDER’s Omega-3s Digital Magazine and hear Bruce Holub speak about this topic in the SupplySide West Podcast 37: Omega-3s' Role in Heart Health.
Bruce Holub, Ph.D., is professor emeritus, department of human health and nutritional sciences, University of Guelph. He received his doctoral degree from the University of Toronto, followed by post-doctoral research as an MRC fellow at the University of Michigan Medical School. Holub has served as president of Nutrition Society of Canada, authored over 200 papers in medical and nutrition journals, and given 400 invited lectures in 20 different countries. His research has been devoted to the health benefits of eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) omega-3s from fish and algal oils, including the prevention and management of cardiovascular disease (CVD).
- He K. “Fish, long-chain omega-3 polyunsaturated fatty acids and prevention of cardiovascular disease – eat fish or take fish oil supplements?” Prog in Cardiovascular Diseases. 2009;52:95-114.
- Alexander D et al. “A meta-analysis of randomized controlled trials and prospective cohort studies of eicosapentaenoic and docosahexaenoic long-chain omega-3 fatty acids and coronary heart disease risk.’’ Mayo Clinic Proc. 2017;92(1):15-29.
- Casula M et al. “Long-term effect of high dose omega-3 fatty acid supplementation for secondary prevention of cardiovascular outcomes: a meta-analysis of randomized double blind, placebo-controlled trials.” Atherosclerosis Suppl. 2013;14:243-251.
- Djousse L et al. “Fish consumption, omega-3 fatty acids and risk of heart failure: a meta-analysis.” Clin Nutr. 2012;31(6):846-853.
- Mozaffarian D et al. “Interplay between different polyunsaturated fatty acids and risk of coronary heart disease in men.” Circulation. 2005;111(2):157-164.
- Albert C et al. “Blood levels of long-chain n-3 fatty acids and the risk of sudden death.” New Engl J Med. 2002;346(15):1113-1118.
- O’Keefe J et al. “ Effects of omega-3 fatty acids on resting heart rate, heart rate recovery after exercise, and heart rate variability in men with healed myocardial infarctions and depressed ejection fractions.” A J Cardiology. 2006;97:1127-1130.