Omega-3 Fatty Acids, Fish Oil, Alpha-Linolenic Acid : Dosing

by MedlinePlus

(Page 4 of 6)

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Standardization:

General: For fish oil supplements, dosing should be based on the amount of EPA and DHA (omega-3 fatty acids) in a product, not on the total amount of fish oil. Supplements vary in the amounts and ratios of EPA and DHA. A common amount of omega-3 fatty acids in fish oil capsules is 0.18 grams (180mg) of EPA and 0.12 grams (120mg) of DHA. Five grams of fish oil contains approximately 0.17-0.56 grams (170 to 560mg) of EPA and 0.072-0.31 grams (72-310mg) of DHA. Different types of fish contain variable amounts of omega-3 fatty acids, and different types of nuts or oil contain variable amounts of α-linolenic acid.

Amounts of seafood necessary to provide 1 gram of DHA + EPA(based on USDA Nutrient Data Laboratory information): cod (Pacific): 23 ounces; haddock: 15 ounces; catfish: 15-20 ounces; flounder/sole: 7 ounces; shrimp: 11 ounces; lobster: 7.5-42.5 ounces; sardines: 2-3 ounces; crab: 8.5 ounces; cod (Atlantic): 12.5 ounces; clams: 12.5 ounces; scallops: 17.5 ounces; trout: 3-3.5 ounces; salmon: 1.4-4.5 ounces; herring: 1.5-2 ounces; oysters: 2.5-8 ounces; tuna (fresh): 2.5-12 ounces; tuna (canned, light): 12 ounces; tuna (canned, white): 4 ounces; halibut: 3-7.5 ounces; mackerel: 2-8.5 ounces. Cod liver oil: 5 grams; standard fish body oil: 3 grams; omega-3 fatty acid concentrate: 2 grams.

Amounts of α-linolenic acid in nuts and vegetable oils(based on USDA Nutrient Data Laboratory information): canola oil: 1.3 grams/tbsp; flaxseed/linseed oil: 8.5 grams/tbsp; flaxseeds: 2.2 grams/tbsp; olive oil: 0.1 grams/tbsp; soybean oil: 0.9 grams/tbsp; walnut oil: 1.4 grams/tbsp; walnuts (English): 0.7 grams/tbsp.

Calories: Fish oils contain approximately 9 calories per gram of oil.

Vitamin E: Fish oil taken for many months may cause a deficiency of vitamin E, and therefore vitamin E is added to many commercial fish oil products.

Adults (18 years and older):

Average dietary intake of omega-3/omega-6 fatty acids: Average Americans consume approximately 1.6 grams of omega-3 fatty acids each day, of which about 1.4 grams (~90%) comes from α-linolenic acid, and only 0.1-0.2 grams (~10%) from EPA and DHA. In Western diets, people consume roughly 10 times more omega-6 fatty acids than omega-3 fatty acids. These large amounts of omega-6 fatty acids come from the common use of vegetable oils containing linoleic acid (for example: corn oil, evening primrose oil, pumpkin oil, safflower oil, sesame oil, soybean oil, sunflower oil, walnut oil, wheatgerm oil). Because omega-6 and omega-3 fatty acids compete with each other to be converted to active metabolites in the body, benefits can be reached either by decreasing intake of omega-6 fatty acids, or by increasing omega-3 fatty acids.

Recommended daily intake of omega-3 fatty acids (healthy adults): For healthy adults with no history of heart disease, the American Heart Association recommends eating fish at least two times per week. 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.

Hypertriglyceridemia: The effects of omega-3 fatty acid intake on triglyceride-lowering are dose-responsive (higher doses have greater effects). Benefits are seen at doses less than 2 grams per day of omega-3 fatty acids from EPA and DHA, although higher doses may be necessary in people with marked hypertriglyceridemia (>750mg/dL). The American Heart Association, in its 2003 recommendations, reports that supplementation with 2-4 grams of EPA + DHA each day can lower triglycerides by 20-40%. Effects appear to be additive with HMG-CoA reductase inhibitor ("statin") drugs such as simvastatin (Zocor®), pravastatin (Pravachol®) and atorvastatin (Lipitor®). Because of the risk of bleeding from omega-3 fatty acids (particularly at doses greater than 3 grams per day), a physician should be consulted prior to starting treatment with supplements.

Heart disease (secondary prevention): In people with a history of heart attack, regular consumption of oily fish (200-400 grams of fish each week equal to 0.5-0.8 grams [500-800mg] of daily omega-3 fatty acids) or fish oil/omega-3 supplements (containing 0.85-1.8 grams [850-1800mg] of EPA + DHA) appears to reduce the risk of non-fatal heart attack, fatal heart attack, sudden death, and all-cause mortality (death due to any cause). The American Heart Association, in its 2003 recommendations, suggests that people with known coronary heart disease consume approximately 1 gram of EPA and DHA (combined) each day. This may be obtained from eating fish or from fish oil capsule supplements. Because of the risk of bleeding from omega-3 fatty acids (particularly at doses greater than 3 grams per day), a physician should be consulted prior to starting treatment with supplements.

High blood pressure: The effects of omega-3 fatty acids on blood pressure appear to be dose-responsive (higher doses have greater effects). However, intakes of greater than 3 grams of omega-3 fatty acids per day may be necessary to obtain clinically relevant effects, and at this dose level, there is an increased risk of bleeding. Therefore, a physician should be consulted prior to starting treatment with supplements.

Rheumatoid arthritis: Clinical trials have used a range of doses, most commonly between 3 and 5 grams of EPA + DHA daily (1.7 to 3.8 grams of EPA, and 1.1 to 2.0 grams of DHA). Effects beyond three months of treatment have not been well evaluated.

Protection from cyclosporine toxicity in organ transplant patients: Studies have used 6 grams of fish oil per day for up to one year. Some research has started at 3 grams daily for six weeks, followed by 6 grams per day). Up to 12 grams per day has been used.

Other: Omega-3 fatty acids are used for numerous other indications, although effective doses are not clearly established. Supplementation with 2g per day of fish oil was well tolerated and was associated with a significant increase in heart rate variability (HRV). Supplementation with 2g per day of soy oil was associated with a lesser but significant increase in HRV.

Children (younger than 18 years):

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.

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