When a mainstream health organization like the American Heart Association (AHA) recommends fish-oil supplements to people with high triglycerides, it’s truly a sea change. I believe we’ve turned the tide in thinking about these beneficial sources of omega-3 fatty acids, nutrients that are essential for the brain and the production of hormones, but are not typically consumed in sufficient amounts from food. Most Americans get too many omega-6 fatty acids (from vegetable oils) but not enough omega-3s (from fatty fish, ground flax meal, and walnuts). This imbalanced ratio may increase risks for heart disease, cancer, inflammatory disorders, and other conditions. For this reason, I advise cutting back on omega-6s while increasing omega-3s. This can be hard to do through diet alone, especially if you don’t eat fish twice weekly. So people may turn to fish-oil supplements, available in capsules or liquid form.
Who may benefit.
Fish and its oils can directly supply two important omega-3 fatty acids: EPA (eicosapentaenoic acid), which seems to have heart-protective effects, and DHA (docosahexaenoic acid), which appears to benefit the nervous system. Some of the strongest evidence for fish oils is that doses of 2 to 4 grams daily of EPA and DHA combined may help reduce high triglycerides by 20 to 40 percent. This is the dose advised by the AHA, if taken under a physician’s care. One gram (1,000 mg) is the typical daily dose suggested to help modestly reduce high blood pressure, and this amount is also recommended by the AHA to reduce cardiovascular risk for those with existing heart disease. Some short-term studies suggest that at least 3 grams of omega-3s daily may help relieve symptoms of inflammatory conditions and autoimmune disorders such as rheumatoid arthritis and lupus. And there’s preliminary evidence from short-term studies that omega-3s may be beneficial along with conventional medications to treat depression and schizophrenia and, in high doses, bipolar disorder, but more research is needed.
What to know.
The most common side effects are nausea, diarrhea, a fishy aftertaste, and belching (sometimes caused by rancid oils). Since fish oils can decrease blood clotting, they should not be taken by people with bleeding disorders or uncontrolled hypertension; also, avoid if you are scheduled to undergo surgery. People on anticoagulants like Coumadin or heparin should take fish oils only under a doctor’s supervision. If you are taking regular aspirin or supplements with blood-thinning properties such as garlic or ginkgo, fish oils could theoretically increase the risk of bleeding. I am assured that the safety concerns about mercury or other environmental contaminants in fish do not hold true for good-quality fish oils. The oils undergo a rigorous distillation process that removes most toxins, and they also come from species such as sardines, anchovies, salmon, or menhaden (a herring relative) that have lower mercury levels. Choose brands that can back up claims to be contaminant-free, like Nordic Naturals. I don’t recommend cod liver oil instead of fish oils. Even though it’s from a marine source, many brands of cod liver oil are too high in vitamins A and D, which can be toxic in excess amounts. And flaxseed oil doesn’t appear to have the same therapeutic benefits, either. As a plant-derived source of omega-3s, the body can convert only about 15 percent of it to EPA.
How to use.
Instead of taking lots of capsules, I prefer the liquid form (which may be flavored lemon or orange) because I find it easier to use and more economical, especially for higher doses. It can be taken by the spoonful, placed on salads, or blended in a shake. Begin with a small daily dose (say, one-quarter teaspoon or one capsule) and slowly increase the dosage over time, taking it in divided doses throughout the day with meals. Fish oils stay freshest and may avoid rancidity if refrigerated.