Omega-3 fatty acids, fish oil, alpha-linolenic acid
Natural Standard® Patient Monograph, Copyright © 2013 (www.naturalstandard.com). All Rights Reserved. Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.
Background
Dietary sources of omega-3 fatty acids include fish oil and certain plant and nut oils. Fish oil contains both docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), while some nuts (such as English walnuts) and vegetable oils (such as canola, soybean, flaxseed, linseed, and olive oils) contain alpha-linolenic acid (ALA).
There is supportive evidence from multiple studies that suggests the intake of recommended amounts of DHA and EPA in the form of dietary fish or fish oil supplements lowers triglycerides; reduces the risk of death, heart attack, dangerous abnormal heart rhythms, and strokes in people with known cardiovascular disease; slows the buildup of atherosclerotic plaques ("hardening of the arteries"), and lowers blood pressure slightly. However, high doses may have harmful effects, such as an increased risk of bleeding. Although similar benefits have been proposed for alpha-linolenic acid, the scientific evidence is less compelling, and the beneficial effects may be less pronounced.
Some species of fish carry a higher risk of environmental contamination, such as with methylmercury.


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