Fishing & Processing Improve Your Heart Health with Omega-3s from Fish by Joyce A. Nettleton DSc, RD In 2002, the American Heart Association strengthened its recommendation about omega-3 fatty acids, urging people to eat fish twice a week (1). The Association emphasized the importance of consuming fatty fish, such as wild Alaska salmon, rainbow trout, sardines, mackerel, and herring. These fish are the richest sources of EPA and DHA, the primary long-chain omega-3 polyunsaturated fatty acids, which occur naturally only in fish. These fish are also low in environmental contaminants. People who eat fish regularly have a significantly lower risk of heart disease and sudden cardiac death, which kills about 250,000 Americans yearly (2-5). We now understand better how EPA and DHA from fish such as Alaska salmon protect heart health. Omega-3s can multi-task: they affect the heart, blood vessels, immune system, and fat metabolism to combat the development of heart disease. Eating fatty fish brings long-lasting health benefits. How Omega-3s Protect Heart Health Consuming fatty fish such as Alaska salmon reduces the risk of sudden death by 40% to 50% or more. The omega-3s in fish stabilize the electrical rhythms of the heart reducing the chance of fatal cardiac arrhythmias that underlie sudden death. Fish oil omega-3s improve the pattern of different lipids in the blood, reducing triglycerides (fats) and modestly increasing high-density lipoprotein levels, the so-called "good cholesterol." Omega-3s from fish improve the function of coronary arteries. They reduce the production of substances that lead to inflammation, which contributes to a higher heart attack risk. Omega-3s also enhance the ability of the blood vessels to dilate, which, in turn, increases blood flow and lowers blood pressure. Omega-3s reduce blood clotting. As heart disease develops, blood clots form in arteries, particularly around damaged arterial plaques. Plaques are deposits of cells and fatty substances that build up inside coronary arteries. Clots can block blood flow to the heart and cause heart attack. Omega-3s may stabilize arterial plaques making them less likely to burst and trigger blood clot formation. Omega-3s reduce arterial inflammation associated with heart disease. Inflammation greatly increases the risk of heart attack. Omega-3s modestly reduce blood pressure easing the risk of heart attack and stroke. Regular consumption of omega-3s lowers the risk of thrombotic stroke, the most prevalent type of stroke in Americans. Thrombotic stroke occurs when a blood clot blocks a blood vessel in the brain. Consumption of omega-3s from fish improves the effectiveness of statin medication frequently prescribed to lower low-density lipoprotein cholesterol levels. Are All Omega-3s the Same? No. The omega-3 fatty acid, alpha-linolenic acid, occurs in certain plant oils and foods - canola, flaxseed, soybean, and walnuts. However, alpha-linolenic acid cannot achieve many of the effects of EPA and DHA and is much less potent. Very little alpha-linolenic acid, probably less than 2%, is converted to EPA and DHA (6). Although alpha-linolenic acid has some heart health benefits, it is less protective of heart health than the omega-3s in fish. Balancing the Fatty Acids We Eat Seafood provides the omega-3 fatty acids EPA and DHA not found in most other foods. The typical American diet is rich in vegetable oils, hydrogenated fat, and animal fat and is very low in the oils from fish. High intake of animal fat increases risk of heart disease, while very high consumption of vegetable oils such as corn, safflower, and soybean may provide too much omega-6 polyunsaturated fatty acids. Omega-6 polyunsaturated fatty acids lower cholesterol levels, but in excess can encourage blood clot formation and inflammation, thereby increasing risk of heart disease (7). A more healthful balance of fats and oils limits the intake of fats from meats, dairy products, and commercially fried and baked foods. Healthful eating emphasizes the oils containing predominantly monounsaturated fatty acids, such as olive and canola, and ensures that oils from fish are included too. Eating fatty fish improves the balance of different fatty acids in our diet. If You Have Heart Disease . . . People with heart disease or those at high risk of developing it can significantly reduce their risk by eating fish regularly. High risk includes people with type 2 diabetes, elevated low-density lipoprotein cholesterol levels, or a strong family history of heart disease. The American Heart Association recommends that people with heart disease consume about one gram per day of the omega-3 fatty acids, EPA and DHA. This amount can be obtained from eating fatty fish several times a week or taking omega-3 fatty acid capsules containing EPA and DHA. Use EPA and DHA supplements in consultation with your physician. A Word About Type 2 Diabetes Type 2 diabetes affects about 17 million Americans and increases their risk of heart disease and mortality by two to three times. Fortunately, eating fatty fish regularly is beneficial in type 2 diabetes. It decreases the risk of sudden death and cardiac arrhythmias, reduces cardiovascular mortality, improves the abnormalities in blood lipids characteristic of diabetes, improves the function of the blood vessels, reduces inflammation, and lowers blood pressure modestly (8,9). The bad news is that about six million people have the disease or are on the verge of it without knowing it. But recent evidence suggests that eating fatty fish such as Alaska salmon may improve insulin sensitivity and lower the chance that a person with mildly impaired glucose tolerance will develop type 2 diabetes (10). The American Diabetes Association supports the recommendation that people with type 2 diabetes consume fatty fish twice a week (11). References Kris-Etherton PM, Harris WS, Appel LJ. AHA Scientific Statement: Fish consumption, fish oil, omega-3 fatty acids and cardiovascular disease. Circulation 2002;106:2747. Leaf A, Kang JX, Xiao Y-F, Billman GE. Clinical prevention of sudden cardiac death by n-3 polyunsaturated fatty acids and mechanism of prevention of arrhythmias by n-3 fish oils. Circulation 2003;107:2646-2652. Siscovick DS, Raghunathan TE, King I, Weinmann S, Wicklund KG, Albright J, Bovbjerg V, Arbogast P, Smith H, Kushi LH, et al. Dietary intake and cell membrane levels of long-chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest. JAMA. 1995;274:1363-1367. Albert CM, Hennekens CH, O'Donnell CJ, Ajani UA, Carey VJ, Willett WC, Ruskin JN, Manson JE. Fish consumption and risk of sudden cardiac death. JAMA. 1998;279:23-28. Hu FGB, Bronner L, Willett WC, Stampfer MJ, Rexrode KM, Albert CM, Hunter D, Manson JE. Fish and omega-3a fatty acid intake and risk of coronary heart disease in women. JAMA. 2002;287:1815-1821. Pawlosky RJ, Hibbeln JR, Novotny JA, Salem N Jr. Physiological compartmental analysis of alpha-linolenic acid metabolism in adult humans. J Lipid Res. 2001;42:1257-1265. Lands, W.E.M., Libelt, B., Morris, A., Kramer, N.C., Prewitt, T.E., Bowen, P., Schmeisser, D., Davidson, M.H., and Burns, J.H. Maintenance of lower proportions of n-6 eicosanoid precursors in phospholipids of human plasma in response to added dietary n-3 fatty acids. Biochem. Biophys. Acta. 1992;1180:147-162. Sirtori CR, Crepaldi G, Manzato E, Mancini M, Rivellese A, Paoliett R, Pazzucconi F, Pamparana F, Stragliotto E. One-year treatment with ethyl esters of n-3 fatty acids in patients with hypertriglyceridemia and glucose intolerance: reduced triglyceridemia, total cholesterol and increased HDL-C without glycemic alteration. Atherosclerosis. 1998;137:419-427. Hu FB, Cho E, Rexrode KM, Albert CM, Manson JE. Fish and long-chain ?-3 fatty acid intake and risk of coronary heart disease and total mortality in diabetic women. Circulation. 2003;107:1852-1857. Ebbesson S. Fats and diabetes prevention in Inuits. Abstract. International Society for the Study of Fatty Acids and Lipids, May 7-11, 2002, Montreal, Canada. American Diabetes Association. Evidence-based nutrition principles and recommendations for the treatment and prevention of diabetes and related complications. Diabetes Care. 2002;25(Suppl 1):S50-S60. Click here to download and Adobe Acrobat version of this articleRecipes Health Benefits Seafood Facts ALSO SEE: Retail Promotions Foodservice Promotions Catalog Suppliers Directory Marketline site map