A substantial amount of evidence exists supporting the heart-health benefits of eicosapentaenoic acid and docosahexaenoic acid (EPA and DHA), marine-derived omega-3 fatty acids. However, much less evidence exists to demonstrate the positive effects of alpha-linolenic acid (ALA), a plant-based omega-3 fatty acid.
“The benefits reported for EPA and DHA are stronger because supplements of EPA and DHA were tested, and EPA and DHA was the only difference between the treatment and control groups,” said Jennifer Fleming, instructor and clinical research coordinator in nutritional sciences. “In contrast, in the ALA studies, there were diet differences beyond ALA between the treatment and control groups.”
EPA and DHA can be found in seafood and fish oil, and are often consumed in the form of dietary supplements. ALA is found in flaxseed and its oil, vegetable oils, and some nuts, and is now available in supplement form. EPA and DHA have been available for much longer. Other sources of ALA, EPA and DHA are fortified foods such as orange juice, eggs, peanut butter, margarine and bread, among others. While there are many other omega-3 fortified foods in the market place, most are relatively low in omega-3 fatty acids.
Omega-3 fatty acids are considered essential for human health, but the body does not produce them — therefore they must be consumed in order to maintain appropriate levels.
In reviewing existing literature on the subject, the researchers have come to the conclusion that ALA is likely just as effective in preventing cardiovascular disease as EPA and DHA have proven to be, as they report on the current issue of Advances in Nutrition.
“Our understanding of the cardiovascular disease benefits of ALA has advanced markedly during the past decade,” said Penny Kris-Etherton, Distinguished Professor of Nutrition. “Based on the current evidence, ALA decreases CVD risk.”
Fleming and Kris-Etherton believe that dietary recommendations should be amended to increase the amount of ALA consumed, but note that randomized controlled clinical trials need to be conducted in order to determine the amount recommended.
“Heart disease is the leading cause of death in the country,” said Fleming. “Learning what you can do to prevent heart disease is important and relevant for everybody.”
The California Walnut Commission supported this research.
Victoria M. Indivero