29. b (salmon). The long-chain omega-3 fats in fish oil, DHA and EPA, may lower your risk of heart disease (and possibly memory loss, macular degeneration, and cancer). Salmon has more DHA and EPA than tuna. Soy and flaxseed oil contain ALA (alpha- linolenic acid), a shorter-chain omega-3 fat. So far, the evidence that ALA prevents heart disease is uncertain, and the body converts only small amounts of ALA into DHA. Some companies add both ALA and DHA to soy milk (and other foods), but they don't add much DHA.