Fish oil has traditionally been the prime source for two of the omega-3 fatty acids that the literature has most frequently tied to good emotional health: eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) . Many people have used flax seed as a plant substitute for fish oil, hoping that they can take in enough ALA (alpha-linoleic acid) to help their body make sufficient quantities of DHA and EPA from the ALA. Sometimes this can be a little tricky, as the body is not very efficient at converting ALA to EPA and DHA. However, there is controversy in this area as well, and I think we don’t have enough information about how ALA and other omega fats work in the body and the brain.
If you’re looking for a plant source of omega-3 fatty acids, try sea buckthorn that already contains ready-made EPA and DHA as well as a number of other important omegas. Chia seeds also contain significant quantities of omega 3’s.
From The Fix by Dr. Alison