Flax seed is the best plant source of omega 3 fatty acids. Flax seed is rich in EFA – Essential fatty acids. They are particularly valuable because the body needs them to function properly, but can't manufacture them on its own. Essential fatty acids work throughout the body to protect cell membranes. Alpha-linolenic acid (ALA), an omega 3 fatty acid found in flax seed is said to help in the treatment of various ailments.