Clinical trials have demonstrated the value of fish oil in prevention of cardiovascular disorders. Regular consumption of fish or fish oil clearly reduces the risk of heart attacks, strokes, clogged arteries and high blood pressure. There is solid evidence that omega-3 fats reduce the levels of triglycerides, the main form in which fats are stored in the blood [source: Medline Plus]. It is also widely accepted that fish oil helps prevent cardiovascular incidents by reducing the frequency of abnormal heart rhythms, although recent studies on patients with advanced heart disease have cast doubt on this conclusion [source: Weil]. To ensure these cardiovascular benefits, one should consume at least one gram of EPA and DHA daily.
Fish oil's benefits are widely distributed in the body. Its anti-inflammatory effect makes it potentially beneficial to those suffering from joint pain, rheumatoid arthritis and inflammatory bowel disorder. It is also alleged to assist in preventing breast cancer and the complications of diabetes. Fish oil supplementation has been found to reduce the symptoms of lupus, an inflammatory disease [source: Oil of Pisces].
DHA is a crucial ingredient in brain tissue, and, thus, a sufficient intake of fish oil is said to help preserve brain function, prevent memory loss and prevent Alzheimer's disease. Some research has shown that high fish consumption in a population correlates with low rates of depression. Fish oil has also been used in the treatment of psychiatric disorders such as schizophrenia [source: Larsen].
Pregnant and breastfeeding women must keep up their intake of EPA and DHA, since they supply these vital nutrients to the developing fetus and child. Some researchers link DHA deficiency to postpartum depression, premature birth, low birth weight and ADHD [source: Oil of Pisces]. Australian researchers concluded that children with satisfactory fish oil intake are at significantly less risk of asthma, probably because the fatty acids prevent inflammation of the respiratory airways [source: Larsen].