Health officials recommend eating fish at least twice a week, and some doctors advise their patients to take fish oil supplements because fish oils contain two omega-3 fatty acids that may contribute to heart health. The two omega-3 fatty acids are eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA. The ratio of EPA to DHA in fish oil supplements can be determined by checking the amounts listed on the label.
Fish Oil
The American Heart Association recommends making fatty fish a regular part of your diet because fish such as salmon, mackerel, herring, sardines, lake trout and albacore tuna are high in both EPA and DHA. Patients with high triglyceride levels and those with documented coronary artery disease may be advised to take fish oil supplements to get even more EPA and DHA. The AHA says people who need to lower their triglyceride levels may be advised to take 2 to 4 g of EPA plus DHA capsules per day. Those with heart disease are advised to get at least 1 g of EPA plus DHA a day.
Supplements
The amount of fish oil in supplement capsules and the amount of EPA and DHA they contain varies. When you're trying to determine your proper dosage, check the label to see how much of the overall amount of fish oil in the capsule is EPA and DHA. Dosing is based on the omega-3 fatty acids -- not the total amount of fish oil. A 1,000 mg capsule often contains 180 mg or 0.18 g of EPA and 120 mg or 0.12 g of DHA. The World Health Association recommends consuming 0.3 to 0.5 g of EPA and DHA daily. The American Heart Association warns that anyone taking more than 3 g of omega-3 fatty acids from capsules should do so only under a doctor's care.
EPA and DHA
Stephen Kopecky, a professor of medicine at Mayo Clinic, tells U.S. News and World Report that people should look for an EPA to DHA ratio of 3-to-2 -- either three parts EPA to two parts DHA or vice versa because research indicates "either ratio produces heart benefits." In a study of the impact of omega-3 fatty acids on depression, researchers at the University of Illinois Chicago found that DHA alone offered no benefits, but a DHA combined with a rather high dose of EPA did help to improve depressive symptoms.
Side Effects
Fish oil supplements can have annoying side effects, such as bloating, gas, diarrhea and fishy burps and aftertaste. In high doses, fish oil can lead to excessive bleeding. In a small study conducted by the U.S. Agricultural Research Service, scientists tried to determine the separate effects of DHA and EPA. In their study of 10 volunteers, the researchers found that DHA alone may help increase levels of HDL or "good" cholesterol without the prolonged bleeding time side effect.
References
- MayoClinic.com: Omega-3 fatty acids, fish oil, alpha-linolenic acid
- American Heart Association: Fish 101
- University of Maryland Medical Center: Omega-3 Fatty Acids
- USDA Agricultural Research Service: DHA Lowers Blood Triglycerides in Diet Study
- Healthfinder.gov: Certain Formulations of Omega-3s Might Help With Depression
- U.S. News: Fish Oil Supplements, EPA, DHA, and ALA: Does Your Omega-3 Source Matter?
Member Comments