What is omega-3?
Omega-3 is a general term for a series of unsaturated fatty acids. It is an essential nutrient element that are important for many bodily functions. Omega-3 fatty acids are found in certain foods and also come as dietary supplements.
Benefits of Omega-3 on the Cardiovascular Health
Not all fats are bad for the heart. The heart-healthy unsaturated fats are known as omega-3. The 3 main omega-3 fatty acids that are beneficial for cardiovascular health are α-linoleic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Here are several potential mechanisms for the favorable effects of omega-3 fatty acids on overall cardiovascular health.
- Omega-3 lower triglyceride levels and increase high-density lipoprotein (ie, good cholesterol) levels
- Oemga-3 reduces the risk of developing an irregular heart beat (arrhythmias)
- Omega-3 may also increase compliance of arteries, decrease atherosclerosis through their effects on metabolism
Main origins of omega-3 fatty acids
- Marine origins, DHA, EPA (Fish Oil)
- Algae origin, DHA (Algae Oil)
- Plant origin, ALA (olive, soybean, canola, walnut, and flaxseed oils…etc)
Regarding omega-3 fatty acid supplement capsules, in the largest randomized controlled trial to date, consisting of 11 324 patients with coronary heart disease, those who took fish oil and ALA capsules daily had a 15% reduction in death, heart attack, and stroke incidence, a 20% reduction in death from any health-related cause, and a 45% reduction in sudden death from a heart attack in comparison with placebo over 3.5 years of follow-up. In addition, triglyceride levels decreased by 4%.
Eventhrough results from early trials of fish consumption and omega-3 PUFA supplementation, as well the collective observational data, demonstrate a cardioprotective effect of long chain omega-3 fatty acids. In contrast, primary and secondary prevention trials published in the last 6 years report uncertain effects of supplementation and call in to question the efficacy of low dose omega-3 PUFAs in reducing cardiovascular events.
Many studies have shown that omega-3 fatty acids reduce cardiovascular disease and improve outcomes. Although it is unclear whether plant-derived omega-3 fatty acids (ie, ALA) or fish-derived omega-3 fatty acids (ie, DHA, EPA) are more important for the heart, both should be a part of a healthy diet.
Evidence suggests that 0.5 to 1.8 g/d of combined EPA and DHA, either as fatty fish or through supplement capsules, is recommended; 1.5 to 3 g/d of ALA is also beneficial, either through plant-based foods or supplement capsules.
The American Heart Association dietary guidelines recommend including at least 2 servings of fatty fish per week in a healthy diet. Including vegetable oils, such as soybean, canola, walnut, flaxseed, and foods such as walnuts and flaxseeds
- Arnett DK, Blumenthal RS, Albert MA, et al. 2019 ACC/AHA guideline on the primary prevention of cardiovascular disease: Executive summary: A report of the American College of Cardiology/American Heart Association task force on clinical practice guidelines.
- Stone NJ.Fish consumption, fish oil, lipids, and coronary heart disease.Circulation. 1996; 94:2337–2340.
- Hu FB, Bronner L, Willett WC, Stampfer MJ, Rexrode KM, Albert CM, Hunter D, Manson JE.Fish and omega-3 fatty acid intake and risk of coronary heart disease in women.JAMA. 2002; 287:1815–1821.
- Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto miocardico.Lancet. 1999; 354:447–455
- Hensrud DD, Heimburger DC. Nutrition’s interface with health and disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 202.
- Mozaffarian D. Nutrition and cardiovascular and metabolic diseases. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 29.
- US Department of Agriculture and US Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th ed.