Fish Oil
Supplements with Essential Omega 3-6-9 Fatty Acids
What is Fish Oil for?
Fish oils can be obtained from eating fish or by taking supplements. Fish that are especially rich in the beneficial oils known as omega-3 fatty acids include mackerel, tuna, salmon, sturgeon, mullet, bluefish, anchovy, sardines, herring, trout, and menhaden. They provide about 1 gram of omega-3 fatty acids in about 3.5 ounces of fish.
Fish oil supplements are usually made from mackerel, herring, tuna, halibut, salmon, cod liver, whale blubber, or seal blubber. Fish oil supplements often contain small amounts of vitamin E to prevent spoilage. They might also be combined with calcium, iron, or vitamins A, B1, B2, B3, C, or D.
Fish oil is used for a wide range of conditions. It is most often used for conditions related to the heart and blood system. Some people use fish oil to lower blood pressure or triglyceride levels (fats related to cholesterol). Fish oil has also been tried for preventing heart disease or stroke. The scientific evidence suggests that fish oil really does lower high triglycerides, and it also seems to help prevent heart disease and stroke when taken in the recommended amounts. Ironically, taking too much fish oil can actually increase the risk of stroke.
Fish may have earned its reputation as “brain food” because some people eat fish to help with depression, psychosis, attention deficit-hyperactivity disorder (ADHD), Alzheimer’s disease, and other thinking disorders.
Some people use fish oil for dry eyes, glaucoma, and age-related macular degeneration (AMD), a very common condition in older people that can lead to serious sight problems.
Women sometimes take fish oil to prevent painful periods; breast pain; and complications associated with pregnancy such as miscarriage, high blood pressure late in pregnancy, and early delivery.
Fish oil is also used for diabetes, asthma, developmental coordination disorders, movement disorders, dyslexia, obesity, kidney disease, weak bones (osteoporosis), certain diseases related to pain and swelling such as psoriasis, and preventing weight loss caused by some cancer drugs.
Fish oil is sometimes used after heart transplant surgery to prevent high blood pressure and kidney damage that can be caused by the surgery itself or by drugs used to reduce the chances that the body will reject the new heart. Fish oil is sometimes used after coronary artery bypass surgery. It seems to help keep the blood vessel that has been rerouted from closing up.
Two of the most important omega-3 fatty acids contained in fish oil are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). See separate listings for EPA and DHA.
What is Fish Oil Possibly Effective for?
Lowering fats called triglycerides. High triglycerides are associated with heart disease and untreated diabetes. To reduce the risk of heart disease, doctors believe it is important to keep triglycerides below a certain level. Doctors usually recommend increasing physical activity and restricting dietary fat to lower triglycerides. Sometimes they also prescribe drugs such as gemfibrozil (Lopid) for use in addition to these lifestyle changes. Now researchers believe that fish oil, though not as effective as gemfibrozil, can reduce triglyceride levels by 20% to 50%. One particular fish oil supplement called Lovaza has been approved by the FDA to lower triglycerides. Lovaza contains 465 milligrams of EP and 375 milligrams of DHA in 1-gram capsules.
• Alzheimer’s disease. There is some preliminary evidence that fish oil may help prevent Alzheimer‘s disease. But it doesn’t seem to help prevent a decline in thinking skills for most people who already have mild-to-moderate Alzheimer’s disease.
• Hereditary chronic inflammation of the skin (atopic dermatitis). Mothers who take fish oil supplements during pregnancy might reduce the severity of atopic dermatitis in babies who are at risk for this condition. But fish oil doesn’t seem to be effective for treating atopic dermatitis.
• Irregular heartbeat affecting the upper chambers of the heart (atrial fibrillation). Research studies into the effects of fish oil on atrial fibrillation have produced conflicting results.
• Cancer. Research studies into the effects of fish oil on cancer prevention have produced conflicting results.
• Cataracts. There is some evidence that eating fish three times a week can modestly lower the risk of developing cataracts.
• Chronic fatigue syndrome (CFS). There is some conflicting evidence about the use of a product (Efamol Marine) that combines fish oils and evening primrose oil to reduce the symptoms CFS.
• Chronic kidney disease. Preliminary evidence shows that fish oil might have benefit for some people with chronic kidney disease who are receiving dialysis treatments.
• Thinking skills (cognitive function). Research studies into the effects of fish oil on cognitive function have produced conflicting results.
• Crohn’s disease. Research studies into the effects of fish oil on Crohn’s disease have produced conflicting results.
• Prediabetes. Early studies suggest that fish oil may help prevent prediabetes from advancing to type 2 diabetes.
• Infant development. There is some evidence that mothers who take 4 grams of fish oil daily during the last half of pregnancy may improve their baby’s cognitive development by some measures, but not others. At age 2.5 years, these children seem to have better hand and eye coordination, but reasoning, social, motor, and speech skills are not significantly improved.
• Ulcerative colitis. Research studies into the effects of fish oil on ulcerative colitis have produced conflicting results.
• Pregnancy complications. There is some evidence that taking fish oil during the last ten weeks of pregnancy can help prevent premature delivery. However, fish oil doesn’t seem to help prevent high blood pressure during pregnancy.
• Prematurity. Baby formula that has been fortified with fatty acids from fish oils and borage seems to improve growth and the development of the nervous system in premature infants, especially boys.
• Schizophrenia. There is one report of fish oil improving schizophrenia in a pregnant woman.
• Systemic lupus erythematosus (SLE). Research shows conflicting results. Some studies suggest that fish oil helps the symptoms of SLE, while others show no effect.
• Irregular heartbeat affecting the ventricles (ventricular arrhythmias). Research studies into the effect of fish oil on ventricular arrhythmias have produced conflicting results.
• Improving night vision in children with a disorder called dyslexia. Children with dyslexia who take fish oil seem to be significantly better able to adapt to the dark.
