Omega-3 fatty acids, which are found in primarily in fish oils but are also present in vegetable oils, are essential fatty acids - in that they are not made by the body and must be supplied by the diet or supplements. Scientists first became interested in omega-3 fatty acids when it was reported that the Eskimo population, who eat a diet rich in fish oil, had a low rate of heart disease. Mackerel, salmon, sea bass, trout, herring, sardines, sablefish (black cod), anchovies, and tuna, as well as cod liver oil supplements, are rich sources of both DHA and EPA. Fish oil contains two types of omega-3 fatty acids: DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). The majority of fish oil supplements contain 18% EPA and 12% DHA.

Recent research has found that omega-3’s acids taken in supplement form can significantly lower the risks associated with heart disease. Some studies have found that while omega-3’s appear to have little effect on total cholesterol levels, they can significantly decrease serum triglyceride levels, lower blood pressure, and reduce blood levels of homocysteine, high levels of which are associated with an increased risk of heart disease and stroke. Elevated homocysteine levels have also been linked to Alzheimer’s disease, Parkinson’s disease, and osteoporosis Omega-3’s also help to thin the blood by discouraging platelets in the blood from clumping together, thus reducing the risk that blood will clot and cause a heart attack. Preliminary research also suggests that omega-3 fatty acids from fish oil may help regulate the rhythm of the heart, as both EPA and DHA have been reported to help prevent cardiac arrhythmias. Potent anti-inflammatory agents, omega-3’s help curb an overactive immune system and thus are helpful in the treatment of autoimmune diseases such as rheumatoid arthritis, chronic inflammatory bowel disease, Crohn’s disease, and psoriasis.

Omega-3’s are also effective in curbing the inflammatory response to severe burns, sepsis, systemic inflammatory response syndrome (SIRS) and asthma. At least one study has found that omega-3’s can improve the clinical outcome for newly diagnosed multiple sclerosis patients.

Omega-3 fats are required for normal brain development during pregnancy and during the first two years of life. If mother and infant are deficient in Omega-3 fatty acids, the infant’s immune and nervous systems may not develop correctly.

Eat fish several times a week for naturally occurring omega-3s and the nutrients that accompany them. Use canola oil in cooking and salad dressings. Fish oil capsules should be taken only with guidance from a qualified nutritionist. The majority of research into the effects of DHA and EPA in humans have used doses of at least 3g of DHA plus EPA supplements. To obtain a similar amount of DHA and EPA from fish oil it may be necessary to consume as much as 10g, as most fish oils contains only 18% EPA and 12% DHA.

Not established - however the one study found that the maximum amount of fish oil tolerated by people being treated for cancerrelated weight loss was roughly 21g per day. Although the maximum tolerated amount in people without cancer may well be different.

People with heart disease or diabetes should consult their doctor before taking more than 3g of fish oil a day as there is some evidence to suggest that the supplement may raise cholesterol levels and blood sugar levels.