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Omega-3 Fatty Acids and Cardiovascular Disease Prevention


Am Fam Physician. 2019 Aug 15;100(4):209-210.


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No deaths from any cause, cardiovascular disease, cardiovascular events, arrhythmias, or strokes were prevented

1 in 14 participants experienced nausea



No deaths from any cause, cardiovascular disease, cardiovascular events, arrhythmias, or strokes were prevented

1 in 14 participants experienced nausea

Details for This Review

Study Population: Adults 18 years and older with varying levels of cardiovascular risk

Efficacy End Points: All-cause mortality, cardiovascular mortality, cardiovascular events, arrhythmia, stroke

Harm End Points: Nausea, abdominal pain or discomfort, diarrhea, reflux, any gastrointestinal side effect, headache or worsening migraine, joint and muscle pain, skin problems, gastrointestinal bleeding, hospitalization, pulmonary embolism (PE) or deep venous thrombosis (DVT)

Narrative: Noncommunicable diseases have overtaken communicable diseases as the major disease burden worldwide, with circulatory and cardiovascular diseases (CVD) remaining the leading cause of death globally.1 Researchers have long investigated the health effects of omega-3 polyunsaturated fatty acids (PUFAs), including eicosapentaenoic acid (EPA; C20:5) and docosahexaenoic acid (DHA; C22:6), on prevention of CVD. Dietary fatty acids may be oxidized for energy, stored in adipose tissue, or further metabolized to various long-chain PUFAs. Membrane-derived PUFAs serve as substrates for formation of eicosanoid effectors (omega-3 and omega-6).2 The effectors derived from omega-3 PUFAs are less inflammatory and platelet aggregating than their omega-6-derived counterparts.2

The primary source of nonprescription omega-3 PUFA supplements is fish oil.3 In 2012, 7.8% of U.S. adults (18.8 million) reported consuming a fish oil dietary supplement within the past 30 days.4 An American Heart Association report suggested that omega-3 PUFA supplements may reduce death from coronary heart disease (CHD), possibly through a reduction in ischemia-induced sudden cardiac death, among patients with previous CHD. The report found that these supplements do not reduce the incidence of recurrent nonfatal myocardial infarction.3 Because benefits likely outweigh the risks, the American Heart Association report offered a Class IIa recommendation (benefits outweigh risks; additional studies with focused objectives needed; it is reasonable to administer treatment) for the use of omega-3 PUFA supplements for the secondary prevention of CHD death.3

The meta-analysis discussed here analyzes the effectiveness of dietary omega-3 PUFA supplementation with EPA (fish-derived; C20:5), DHA (fish-derived; C22:6) and alpha-linolenic acid (plant-derived; C18:3) to improve all-cause mortality, cardiovascular deaths, cardiovascular events, arrhythmias, and stroke. The meta-analysis included 79 randomized controlled trials (RCTs), including 112,059 participants,

Author disclosure: No relevant financial affiliations.


show all references

1. Roth GA, Huffman MD, Moran AE, et al. Global and regional patterns in cardiovascular mortality from 1990 to 2013. Circulation. 2015;132(17):1667–1678....

2. Elamin EM, Miller AC, Ziad S. Immune enteral nutrition can improve outcomes in medical-surgical patients with ARDS: a prospective randomized controlled trial. J Nutr Disord Ther. 2012;2:109.

3. Siscovick DS, Barringer TA, Fretts AM, et al.; American Heart Association Nutrition Committee of the Council on Lifestyle and Cardiometabolic Health; Council on Epidemiology and Prevention; Council on Cardiovascular Disease in the Young; Council on Cardiovascular and Stroke Nursing; and Council on Clinical Cardiology. Omega-3 polyunsaturated fatty acid (fish oil) supplementation and the prevention of clinical cardiovascular disease: a science advisory from the American Heart Association. Circulation. 2017;135(15):e867–e884.

4. Clarke TC, Black LI, Stussman BJ, et al. Trends in the use of complementary health approaches among adults: United States, 2002–2012. Natl Health Stat Report. 2015;(79):1–16.

5. Abdelhamid AS, Brown TJ, Brainard JS, et al. Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev. 2018;(11):CD003177.



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