Omega-3 fatty acids are a type of polyunsaturated fat that are necessary for such bodily processes as blood clotting and building cell membranes in the brain. Omega-3 fatty acids are an essential nutrient, since our body cannot make them. They are found in walnuts, flaxseed, soybean and canola oil and fish oil, as well as in cold-water fish such as trout, herring, and salmon. Research has revealed their potential for protecting against heart disease, stroke and rheumatoid arthritis.

Cardiovascular Disease

The Office of Dietary Supplements reports research findings that reveal a decrease in triglycerides, or fat in the blood, of 10 to 33 percent in those individuals who consumed fish oil. It was also shown that the greater the dose of fish oil, the greater the decrease in triglyceride levels. In addition, consumption of omega-3 fatty acids, fish and fish oil have been shown to reduce all causes of mortality and various cardiovascular disease outcomes such as sudden death, cardiac death and myocardial infarction, or heart attack.

Diabetes

According to the Office of Dietary Supplements, since omega-3 fatty acid consumption has been shown in various research studies to decrease triglyceride levels, and since high triglyceride levels have been shown to be a risk factor for diabetes, omega-3 fatty acid consumption may help decrease risk of developing diabetes.

Rheumatoid Arthritis

Various studies have shown that omega-3 fatty acid consumption may help improve clinical outcomes for those with rheumatoid arthritis. For example, a study reported by the Office of Dietary Supplements showed that consumption of omega-3 fatty acids reduced the need for corticosteroid medication, which helps in pain relief, in those individuals with rheumatoid arthritis. In addition, omega-3 fatty acid consumption was shown to reduce tender joint count, or the number of joints susceptible to pain, in those individuals with rheumatoid arthritis.

Cognitive Function

Alpha-linolenic acid, a type of omega-3 fatty acid, is converted in the body to the fatty acids eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA. The Office of Dietary Supplements reports that total omega-3 fatty acid consumption and consumption of DHA were associated with a significant reduction in the incidence of Alzheimer's disease. However, further studies with larger sample sizes need to be done to confirm such findings before further claims can be made about omega-3 fatty acid's protective effects against the disease.