Omega-3 fatty acids are key for normal development and growth. Lack of dietary intake of omega-3 fatty acids and too much intake of omega-6 fatty acids is believed to be a significant contributing factor to many diseases. Since the human body cannot make omega-3 fatty acids, we have to get them from our diet. Omega-3 supplements have become one of the most popular supplements in the U.S. They're used to help prevent and treat a number of serious diseases.
Why do people take omega-3 fatty acids?
Studies show strong evidence that omega-3 fatty acids from fish oil can lower blood pressure and triglyceride levels. There's also good evidence that diets high in omega-3 fatty acids help with rheumatoid arthritis as well as osteoarthritis. Past evidence pointed to omega-3 fatty acids reducing risk of heart attacks, strokes, and death from heart disease, but recent research has refuted some of these findings. More specific research is needed to sort this out.
Omega-3 fatty acids have been studied in many other conditions. They include asthma, cancer, depression, psoriasis, and inflammatory bowel diseases such as Crohn's disease and ulcerative colitis. While some of these studies have been promising, they're still inconclusive.
The different types of omega-3 fatty acids can be confusing. There are the fish oils, which contain docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Then there are the plant sources with alpha-linolenic acid (ALA), which is converted into omega-3 fatty acids in the body.
Studies have generally used fish oils as the source for omega-3 fatty acids. While plant sources with ALA may have the same benefits, less is known about them. For now, fish oils with DHA and EPA have the more established benefit.
How much omega-3 fatty acids should you take?
There are no standard doses for omega-3 fatty acids. The American Heart Association (AHA) recommends 1 gram per day of EPA+DHA for people with heart disease. Higher doses -- between 2 to 4 grams per day -- are used to lower triglycerides. If you need to take omega-3 fatty acid supplements, ask your health care provider what dosage you should use. Children shouldn't use omega-3 fatty acid supplements unless a doctor suggests it. The dose of plant-based fatty acids is generally much higher than for fish oils.