Omega-3 essential fatty acids, found in fish and some other oils, have been linked in many studies to a lowered risk of heart disease. The omega-3 fatty acids include alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

The omega-3 series offers a variety of potential therapeutic uses, primarily as part of a heart-protecting diet. Beneficial effects include the following:

• Lowering cholesterol and triglyceride levels
• Reducing the risk of heart disease
• Lowering blood pressure

The omega-3 fatty acids also act as anti-inflammatory agents, making them beneficial for patients with rheumatoid arthritis, osteoarthritis, ulcerative colitis, and lupus. The series also protects myelin, which shields the nerves, and may be helpful in treating a variety of conditions, including glaucoma, multiple sclerosis, osteoporosis, and diabetes, as well as migraines, anorexia nervosa, depression, bipolar disorder, panic attacks, attention deficit/hyperactivity disorder, and agoraphobia. Omega-3 fatty acids have been used to reduce inflammation and promote wound healing in burn victims. Studies also suggest that obese people who follow a weight loss program achieve better control over their blood sugar and cholesterol levels when fish rich in omega-3 fatty acids (such as salmon and mackerel) is a staple in the diet. Omega-3 fatty acids may also be helpful in preventing cancer. For example, some experts believe that omega-3 fatty acids may prove to be valuable in preventing colon cancer or treating it in its early stages. Omega-3 fatty acids may also improve glucose-insulin metabolism and cholesterol in obese person.

Fish oils and plant products are the primary dietary source of omega-3 fatty acids. EPA and DHA are found in cold-water fish such as salmon, mackerel, halibut, and herring, and in animals that feed on these fish. ALA is found in nonhydrogenated oils, such as rapeseed (canola), flaxseed, and soybean oil, and in margarines and other fats containing such oils. After consumption, ALA is converted in the human body to EPA and DHA.

Omega-3 fatty acids are available in two types of commercial preparations:

• Cooking oils (canola, soybean)
• Medicinal oil (flaxseed)

Some manufacturing methods can destroy the nutrient value of the products. Preferred methods tend to use proprietary names for their process, generically known as modified atmospheric packing methods. Generally, a high-quality oil will be certified as organic by a reputable third party, packaged light-resistant containers and dated, and may be refrigerated.

For general health, there should be a balance between omega-6 and omega-3 fatty acids; the ratio should be in the range of 4:1; the typical North American diet normally provides ratios from 14:1 or 20:1. To help achieve the healthier balance, a person eating a typical American diet should reduce consumption of saturated fats and increase consumption of omega-3 polyunsaturated essential fatty acids.

Pediatric

Although dietary guidelines, as described, have been suggested, the precise safe and effective doses of omega-3 fatty acid supplements in children have not been established.

Adult

• One or two tbsp of flaxseed oil daily is considered optimal for a healthy individual. Capsule doses are 3,000 mg per day for prevention and 6,000 mg per day for treatment.
• A diet that gets 1% to 2% of its calories from linolenic acid has been shown to give maximum tissue levels of DHA, avoiding any apparent deficiency symptoms.
• For rheumatoid arthritis, the estimated therapeutic dose of ALA is 5 g/day, while the estimated therapeutic dose of EPA is 1.8 g/day.
• For agoraphobia: 2 to 6 tbsp of flaxseed oil daily, in divided doses.

The ratio of omega-3 fatty acids to other essential fatty acids may be important in treating some conditions. Take omega-3 oils cautiously if you bruise easily, have a bleeding disorder, or take blood-thinning medication.

Excessive amounts of omega-3 fatty acids may increase the amount of time that it takes for the blood to clot following a cut or other injury.

Omega-3 fatty acids may increase the blood-thinning effects of aspirin. While this combination may be helpful in the treatment of some diseases, you should only take omega-3 fatty acids under the guidance and supervision of your healthcare provider.

Taking omega-3 fatty acids during cyclosporine therapy may reduce toxic side effects associated with this medication in transplant patients. Use of omega-3 fatty acids with cyclosporine should only be done with the approval of your healthcare provider.

In a scientific study, the addition of omega-3 fatty acids, specifically EPA, to a regimen of etretinate and topical corticosteroids to treat psoriasis, resulted in improvement of symptoms. Consult your healthcare provider about whether omega-3 supplementation would be of benefit to you.

In an animal study, treatment with omega-3 fatty acids protected against the possibility of ulcers from nonsteroidal anti-inflammatory drugs (NSAIDs). More research is needed to evaluate whether omega-3 fatty acids would have the same effects in people. Until more is known, you should consult with your doctor before taking omega-3 supplements if you are currently taking NSAIDs.

Al-Harbi MM, Islam MW, Al-Shabanah OA, Al-Gharably NM. Effect of Acute Administration of Fish Oil (Omega-3 Marine Triglyceride) on Gastric Ulceration and Secretion Induced by Various Ulcerogenic and Necrotizing Agents in Rats. Fed Chem. Toxic. 1995;33(7):555-558.

Ando H, Ryu A, Hashimoto A, Oka M, Ichihashi M. Linoleic acid and alpha-linolenic acid lightens ultraviolet-induced hyperpigmentation of the skin. Arch Dermatol Res. July 1998;290(7):375-381.

Andreassen AK, Hartmann A, Offstad J, Geiran O, Kvernebo K, Simonsen S. Hypertension prophylaxis with omega-3 fatty acids in heart transplant recipients. J Am Coll Cardiol 1997;29:1324-1331.

Badalamenti S, Salerno F, Lorenzano E, et al. Renal Effects of Dietary Supplementation With Fish Oil in Cyclosporine-Treated Liver Transplant Patients. Hepatol. 1995;2(6):1695-1701.

Billeaud C, Bougle D, Sarda P, et al. Effects of preterm infant formula supplementation with alpha-linolenic acid with a linoleate/alpha-linoleate ration of 6. Eur J Clin Nutr. 1997;51(8):520-527.

Danno K, Sugie N. Combination therapy with low-dose etretinate and eicosapentaenoic acid for psoriasis vulgaris. J Dermatol. 1998;25:703-705.

DeDeckere EA, Korver O, Verschuren PM, Katan MB. Health aspects of fish and n-3 polyunsaturated fatty acids from plant and marine origin. Eur J Clin Nutr. 1998;52(10):749-753.

Edwards R, Peet M, Shay J, Horrobin D. Omega-3 polyunsaturated fatty acid levels in the diet and in red blood cell membranes of depressed patients. J Affect Disord. 1998;48(2-3):149-155.

Ensminger AH, Ensminger ME, Konlande JE, Robson JRK. Foods & Nutrition Encyclopedia. 2nd ed. Vol 2. Boca Raton, Fla: CRC Press, Inc; 1994:684-708.

Garrison RH Jr, Somer E. The Nutrition Desk Reference. 3rd ed. New Canaan, Conn: Keats Publishing, Inc; 1995:23-64.

Haas EM. Staying Healthy with Nutrition. Berkley, Calif: Celestial Arts Publishing; 1992:65-79.

Harris WS. N-3 fatty acids and serum lipoproteins: human studies. Am J Clin Nutr. 1997;65(5):1645S (10).

Haw M, Linnebjerg H, Chavali SR, Forse RA. The effect of dietary polyunsaturated fatty acids (PUFA) on acute rejection and cardiac allograft blood flow in rats. Transplantation. 1995;60(6):570-577.

Homan van der Heide JJ, Bilo HJ, Tegzess AM, Donker AJ. The effects of dietary supplementation with fish oil on renal function in cyclosporine-treated renal transplant recipients. Transplantation. 1990;49:523-527.

Iacoviello K, Amore C, De Curtis A, et al. Modulation of fibrinolytic response to venous occlusion in humans by a combination of low-dose aspirin and n-3 polyunsaturated fatty acids. Arterioscler Thromb 1992;12(10):1191-1197.

Kooijmans-Coutinho MF, Rischen-Vos J, Hermans J, Arndt JW, van der Woude FJ. Dietary fish oil in renal transplant recipients treated with cyclsporin-A: no beneficial effects shown. J Am Soc Nephrol. 1996;7(3):513-518.

Murray MT. Encyclopedia of Nutritional Supplements. Rocklin, Calif: Prima Publishing; 1996:239-278.

Murray MT, Pizzorno JE. Encyclopedia of Natural Medicine. 2nd ed. Rocklin, Calif: Prima Publishing; 1996:49-52, 255, 266, 487, 533-34, 765-66, 779-781.

Nestel PJ, Pomeroy SE, Sasahara T, et al. Arterial compliance in obese subjects is improved with dietary plant n-3 fatty acid from flaxseed oil despite increased LDL oxidizability. Arterioscler Thromb Vasc Biol. July 1997;17(6):1163-1170.

Newstrom H. Nutrients Catalog. Jefferson, NC: McFarland & Co., Inc.; 1993:103-105.

Shils ME, Olson JA, Shike M, Ross AC. Modern Nutrition in Health and Disease. 9th ed. Baltimore, Md: Williams & Wilkins; 1999:90-92, 1377-1378.

Stoll AL, Severus WE, Freeman MP, et al. Omega 3 fatty acids in bipolar disorder: a preliminary double-blind placebo-controlled trial. Arch Gen Psychiatry. 1999:56(5):407-412.

Ventura HO, Milani RV, Lavie CJ, Smart FW, Stapleton DD, Toups TS, Price HL. Cyclosporine induced hypertension. Efficacy of omega-3 fatty acids in patients after cardiac transplantation. Circ. 1993;88(5 Pt 2):II281-285.

Von Schacky C, Angerer P, Kothny W, et al. The effect of dietary omega-3 fatty acids on coronary atherosclerosis. A randomized, double-blind, placebo-controlled trial. Ann Intern Med. 1999;107(7):554-562.

Voskuil DW, Feskens EJM, Katan MB, Kromhout D. Intake and sources of alpha-linolenic acid in Dutch elderly men. Euro J Clin Nutr. 1996;50(12):784-787.

Wagner W, Nootbaar-Wagner U. Prophylactic treatment of migraine with gamma-linolenic and alpha-linolenic acids. Cephalalgia. 1997;17(2):127-130.

Werbach MR. Nutritional Influences on Illness. 2nd ed. Tarzana, Calif: Third Line Press; 1993:13-22, 655-671.

Yehuda S, Rabinovitz S, Carasso RL, Mostofsky DI. Fatty acids and brain peptides. Peptides. 1998;19(2):407-419.

<UpdateDate)March 2001