Over the past decade, Omega-3 fatty acids have gained widespread attention in both medical communities as well as in lay press for their health benefits. Omega-3 fatty acids are considered essential fatty acids. They are essential to human health but cannot be manufactured by the body. For this reason, omega-3 fatty acids must be obtained from food. Omega-3 fatty acids can be found in fish, such as salmon, tuna, and halibut, other marine life such as algae & krill and nut oils. Also known as polyunsaturated fatty acids (PUFAs), omega-3 fatty acids play a crucial role in brain function as well as normal growth and development. The American Heart Association recommends eating fish (particularly fatty fish such as mackerel, lake trout, herring, sardines, albacore tuna, and salmon) at least 2 times a week. Some species of fish carry a higher risk of environmental contamination, such as with methylmercury. It is advised that pregnant women and mothers, nursing mothers, young children, and women who might become pregnant not eat several types of fish, including swordfish, shark, and king mackerel. These individuals should also limit consumption of other fish, including albacore tuna, salmon, and herring. They can take omega-3 fatty acids in quality dietary supplements that are certified mercury-free by a reputable third-party lab. There are three major types of omega 3 fatty acids that are ingested in foods and used by the body: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Once eaten, the body converts ALA to EPA and DHA, the two types of omega-3 fatty acids more readily used by the body.
HEALTH BENEFITS of Omege-3 fatty acids Evidence from several studies has suggested that amounts of DHA and EPA in the form of fish or fish oil supplements have many health benefits. The latest literature on these benefits is given below:
Strong Evidence Support for use
- High Blood Pressure. DHA may have greater benefits than EPA. However, it may be necessary to take high amounts of omega-3 fatty acids per day to obtain these health benefits, and high doses may increase the risk of bleeding. Therefore, a qualified healthcare provider should be consulted before starting treatment with fish oil supplements.
- Hypertriglyceridemia. EPA & DHA significantly reduce blood triglyceride levels. Benefits appear to be dose-dependent. Fish oil supplements also appear to cause small improvements in high-density lipoprotein (“good cholesterol”); however, increases (worsening) in low-density lipoprotein levels (LDL/”bad cholesterol”) have also been observed. It is not clear if alpha-linolenic acid significantly affects triglyceride levels.
- Preventing Heart Attacks. Regular consumption of oily fish or fish oil/omega-3 supplements reduces the risk of non-fatal heart attacks, fatal heart attacks, sudden death, and deaths due to any cause in people with histories of heart attacks.
Good Evidence Support for use
- Infant Brain Development. Infants have improved problem solving skills but not memory if their mothers consume DHA-containing functional foods during pregnancy.
- Arthritis. Omega-3 fatty acids help reduce inflammation. Many studies report improvements in morning stiffness and joint tenderness with the regular intake of fish oil supplements for up to three months.
- Pregnancy. DHA has been found to be important for healthy pregnancies. DHA supplementation during pregnancy plays an important role in the development of the visual system.
Unclear Evidence Support for use
- Asthma. Several studies in this area do not provide enough reliable evidence to form a clear conclusion, with some studies reporting no effects, and others finding benefits
- Attention Deficit Hyperactive Disorder (ADHD). There is evidence that polyunsaturated fatty acids (PUFAs) may help treat ADHD-related problems, including inattention, hyperactivity, and impulsivity. More research is needed to confirm these findings.
- Cancer Prevention. Several population (epidemiological) studies report that dietary omega-3 fatty acids or fish oil may reduce the risk of developing breast, colon, or prostate cancer. Better-designed studies are necessary before a clear conclusion can be drawn.
You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
<em>Adults</em> (over 18 years old) For healthy adults with no history of heart disease, the American Heart Association recommends eating fish at least twice weekly. In particular, fatty fish are recommended, such as anchovies, bluefish, carp, catfish, halibut, herring, lake trout, mackerel, pompano, salmon, striped sea bass, tuna (albacore), and whitefish. It is also recommended to consume plant-derived sources of α-linolenic acid, such as tofu, soybeans, walnuts, flaxseed oil, and canola oil. The World Health Organization and governmental health agencies of several countries recommend consuming 0.3-0.5 grams of daily EPA + DHA and 0.8-1.1 grams of daily α-linolenic acid. A doctor should be consulted for dosing for other conditions.
<em>Children </em>(under 18 years old) Omega-3 fatty acids are used in some infant formulas, although effective doses are not clearly established. Ingestion of fresh fish should be limited in young children due to the presence of potentially harmful environmental contaminants. Fish oil capsules should not be used in children except under the direction of a physician.
SAFETY & PRECAUTIONS
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. Consult a healthcare provider immediately if you experience side effects.
- May increase risk of bleeding. Very large intakes of fish oil/omega-3 fatty acids (“Eskimo” amounts) may increase the risk of hemorrhagic (bleeding) stroke. High doses have also been associated with nosebleed and blood in the urine.
- Potentially harmful contaminants such as dioxins, methylmercury, and polychlorinated biphenyls (PCBs) are found in some species of fish. Methylmercury accumulates in fish meat more than in fish oil, and fish oil supplements
- He K, Song Y et al. Accumulated evidence on fish consumption and coronary heart disease mortality. Circulation 2004; 109:2705-2711.
- Harris Ws, Ginsberg HN, Arunakul N, et al. Safety and efficacy of Omacor in severe hypertryglyceridemia. J Cardiovascular Risk 1997; 4:385-391
- Olsen SF, Joensen HD. High liveborn birth weights in the Faroes: A comparison between birth weights in the Faroes and in Denmark. J Epidemiolog Community Health 1985; 39:27
- American Heart Association. Fish and Omega-3 Fatty Acids. Accessed on December 28, 2009.
- Duffy EM, Meenagh GK, McMillan SA, et al. The clinical effect of dietary supplementation with omega-3 fish oils and/or copper in systemic lupus erythematosus. J Rheumatol 2004;31(8):1551-1556