alt Hacker News> But my understanding is non-DHA is not helpful so I may not be understanding correctly
Alpha-linolenic acid (ALA), the Omega-3 present in most plant sources, can get its chemical structure lenghtened to EPA and DHA in the organism. The problem appears to be, when people get older, the efficiency of this conversion takes a large hit.
It’s always a stretch too - takes something like 15x more ALA to convert to DHA when things are going well. Not nothing but if a substantial amount of DHA is protective, it’s hard to get there with only ALA.