9. Flaxseed (2,350 mg per serving)
These small brown or yellow seeds are often ground, milled, or pressed to extract oil.
They are the richest whole food source of the omega-3 fat alpha-linolenic acid (ALA). Therefore, flaxseed oil is often used as an omega-3 supplement.
Flaxseed is also a good source of fiber, magnesium, and other nutrients. The seeds have a great omega-6 to omega-3 ratio compared to most other oily plant seeds.
Because your intestines cannot break down the tough outer shells of whole flaxseed, it may be better to use ground flaxseed or grind whole flaxseed in a coffee grinder.
Omega-3 content: 2,350 mg of ALA per tablespoon (10.3 g) of whole seeds, or 7,260 mg per tablespoon (13.6 g) of oil.