Omega-3 fatty acids are a group of polyunsaturated fatty acids that can't be made by the body and must be obtained through food sources. There are three main kinds: alpha-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). ALA is found in leafy vegetables, fruits, nuts, seeds, legumes and grains. DHA and EPA are found in fish (especially fatty fish, like tuna, trout, salmon), fish oils and algae. The body is able to convert ALA into DHA, but only in small amounts. So it's important to eat foods with DHA and EPA. Some foods are also fortified with omega-3 fatty acids.

Omega-3 fatty acids are important nutrients for the body. Research suggests they may help fight inflammation and reduce the risk of heart disease, heart attack, rheumatoid arthritis and ulcerative colitis. DHA is needed to support the growth and development of the fetal brain and eyes. DHA and EPA may also play a role in risk for attention deficit/hyperactivity disorder, dyslexia, autism, mood disturbances and aggressive behaviors.

Using Fish Oil Supplements

The American Heart Association currently recommends that healthy American adults eat fish (fatty fish are best) at least twice a week and to include oils and foods high in ALA (like canola, soybean and flaxseed oils and walnuts). Patients with heart disease should get at least one gram of omega-3 fatty acids daily.

Despite the benefits of fatty fish, experts say the average American only gets about 150 mg of omega-3 fatty acids a day, the equivalent of about one fish portion every 10 days. Some people don't like fish. Others may be concerned about the potential for fish contamination from toxic compounds, like mercury, dioxins and polychlorinated biphenyls (PCBs).

One way to increase intake of omega-3 fatty acids without eating fish is by taking fish oil capsules. Tod Cooperman, M.D., President of ConsumerLab.com, says fish oil capsules are derived from fish that is processed and distilled to remove toxins. Thus, in some cases, they may be safer than eating fish. The supplements are also relatively cheap. A month's supply of fish oil capsules can cost less than one pound of some types of fish.

ConsumerLab.com reports Americans spent $489 million on fish oil supplements in 2006. To determine if people are getting what they are paying for, the organization analyzed 50 different supplements, foods and beverages with omega-3 fatty acids for safety and concentration. The investigators found all the products contained safe levels of contaminants. All but one product was found to have the correct amount of omega-3s listed on the label.

Cooperman says some fish oil capsules have an enteric coating that prevents break down of the capsule until it leaves the stomach. This prevents the fishy after-taste and bad breath sometimes associated with fish oil capsules. The breakdown of this coating is important. If it dissolves too quickly, the fish oil is released before the capsule passes through the stomach. If it dissolves too slowly, the fish oil may pass through the body without much benefit. Only one enteric-coated fish oil supplement dissolved too quickly, failing the simulated gastric fluid test.

With so many fish oil supplements available, it can be difficult to make a product choice. Cooperman recommends looking for a product that contains the key ingredients in omega-3 fatty acids, EPA and DHA. There's no government standard for how much you should take. Cooperman suggests around 500 mgs of combined EPA/DHA a day, with a minimum of 200 milligrams of each ingredient. To avoid the unpleasant taste, try enteric coated capsules.

ConsumerLabs.com recommends taking fish oil capsules with meals and dividing the doses to be taken throughout the day. Keep the capsules away from heat and light to maintain freshness and prevent spoilage. You can also keep the pills in a refrigerator. Liquid omega-3 supplements should also be refrigerated. The liquid may get cloudy or appear to separate with refrigeration. Simply shake the bottle before each use.

Experts warn fish oil supplements can interfere with blood clotting. So they should be used cautiously in people with bleeding disorders, those who are taking blood thinners and patients who are having surgery. Some people prefer cod liver oil instead of fish oil supplements. Cooperman warns that although cod liver oil contains omega-3s, it also has vitamin A, which can be toxic in high levels.

For information about the study, go to http://www.ConsumerLab.com.