Adv Nutr. 2014 Nov; 5(6): 863S–876S.
Published online 2014 Nov 3. doi: 10.3945/an.114.005850

The Evidence for α-Linolenic Acid and Cardiovascular Disease Benefits: Comparisons with Eicosapentaenoic Acid and Docosahexaenoic Acid1,2

Jennifer A. Fleming and Penny M. Kris-Etherton*
Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA

Abstract
Our understanding of the cardiovascular disease (CVD) benefits of α-linolenic acid (ALA, 18:3n–3) has advanced markedly during the past decade. It is now evident that ALA benefits CVD risk. The expansion of the ALA evidence base has occurred in parallel with ongoing research on eicosapentaenoic acid (EPA, 20:5n–3) and docosahexaenoic acid (DHA, 22:6n–3) and CVD. The available evidence enables comparisons to be made for ALA vs. EPA + DHA for CVD risk reduction. The epidemiologic evidence suggests comparable benefits of plant-based and marine-derived n–3 (omega-3) PUFAs. The clinical trial evidence for ALA is not as extensive; however, there have been CVD event benefits reported. Those that have been reported for EPA + DHA are stronger because only EPA + DHA differed between the treatment and control groups, whereas in the ALA studies there were diet differences beyond ALA between the treatment and control groups. Despite this, the evidence suggests many comparable CVD benefits of ALA vs. EPA + DHA. Thus, we believe that it is time to revisit what the contemporary dietary recommendation should be for ALA to decrease the risk of CVD. Our perspective is that increasing dietary ALA will decrease CVD risk; however, randomized controlled clinical trials are necessary to confirm this and to determine what the recommendation should be. With a stronger evidence base, the nutrition community will be better positioned to revise the dietary recommendation for ALA for CVD risk reduction.

Conclusions
On the basis of the current review, there is evidence demonstrating a beneficial role of ALA for the primary and secondary prevention of CVD. A similar conclusion was reached by Mozaffarian (18) who recommended that ALA intake be increased to 2–3 g/d to reduce risk of CVD. As discussed in this review, on the basis of the epidemiologic data, there may be comparable CVD benefits for EPA + DHA vs. ALA. However, there is a lack of sufficient evidence from well-controlled clinical trials on the effects of ALA on CVD risk, and consequently, establishing a recommended amount will require additional research. Thus, we propose that clinical trials be conducted to evaluate the quantitative effects of ALA intake on CVD risk. In conjunction with this, and given that a dietary recommendation exists for EPA + DHA, there also is a pressing need to further assess the collective benefits of all (both plant- and marine-derived) n–3 PUFAs on CVD risk. It is obvious that the collective cardioprotective effect of dietary n–3 PUFAs is dependent on establishing the recommended amount of ALA. This is important because it is probable that the greatest CVD benefit will be dependent on the “optimal” quantity of all dietary n–3 PUFAs, both plant- and marine-derived sources.

The Evidence for α-Linolenic Acid and Cardiovascular Disease Benefits: Comparisons with Eicosapentaenoic Acid and Docosahexaenoic Acid
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4224228/