Alpha-linolenic acid is a kind of omega-3 fatty acid found in plants. It is similar to the omega-3 fatty acids that are in fish oil, called eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Your body can change alpha-linolenic acid into EPA and DHA. Alpha-linolenic acid is found in flaxseed oil, and in canola, soy, perilla, and walnut oils.
Omega-3 fatty acids — especially EPA and DHA — have been shown to reduce inflammation and may help prevent chronic diseases, such as heart disease and arthritis. They may be also important for brain health and development, as well as normal growth and development.
There is good evidence that fish oil containing EPA and DHA may help treat heart disease, prevent heart attack and stroke, and slightly reduce high blood pressure. Researchers have thought that the same may be true for alpha-linolenic acid. There is evidence that may be so, although it’s not as strong as it is for fish oil.