Alpha-linolenic acid and fish oil n3 fatty acids and cardiovascular disease risk. Reply to E Vos et al.

In this letter to the editor, Lau et al reply to comments recently made by Vos and associates regarding the review paper by Wang (and Lau) et al titled “n-3 fatty acids from fish or fish-oil supplements, but not alpha-linolenic acid, benefits cardiovascular disease outcomes in primary-and secondary-prevention studies: a systematic review”.  Lau et al disagree with Vos’s statement that their review showed “broad enthusiasm for fish oils and outright dismissal of ALA”. 

Lau states that their interpretation and/or decision to include/not include specific studies pertaining to ALA were based on predefined criteria established to minimize bias.  For example, in the case of the Lyon Diet Heart Study, Lau states “this (study) was not designed to show and cannot be construed as showing that ALA was the agent responsible for the reduction in clinical events”.  Lau et al points out that just because an inverse association between serum concentrations of ALA and clinical outcomes of CVD was observed, this does not indicate ALA is solely responsible for the reduced risk.  As such, Lau states that although this evidence is promising, these results need to be directly tested in human randomized controlled trials.  Overall, Lau’s position is that “direct evidence does not support the view that ALA reduces the risk of cardiovascular events”.