Heart disease

The strongest evidence of fish oil's benefits involves its ability to prevent heart disease. Fish oil can lower blood pressure, reduce blood triglyceride levels, and prevent heart attack and other forms of heart disease, according to research compiled by the Mayo Clinic. A UCLA study shows fish oil supplements decreased resting heart rate and improved circulatory function in healthy subjects.

Rheumatoid arthritis

The anti-inflammatory qualities of fish oil help it treat early stage rheumatoid arthritis.

Cancer

Fish oils also show promise in treating and preventing cancer, including colon cancer. The Beth Israel Deaconess Medical Center at Harvard University reports that fish oil supplements help some cancer patients avoid the weight loss that accompanies treatment.

Mental health

Doctors at the Mayo Clinic and the Beth Israel Deaconess Medical Center at Harvard University note that while more research is needed, fish oils show promise in treating depression and bipolar disorder.

Types

Fish oil can be taken in supplement form, but it is readily available in foods, including many grains and fruits and vegetables. Its richest source, according to doctors at the Beth Israel Deaconess Medical Center, is cold-water fish.

Source:

Beth Israel Deaconess Medical Center at Harvard University: fish oil information

Mayo Clinic: fish oil benefits

Journal of Cardiovascular Pharmacology and Therapeutics; Cardiovascular and Endothelial Effects of Fish Oil Supplementation in Healthy Volunteers; Atman Prabodh Shah, MD et al.; 2007