Flax (also known as common flax or linseed), Linum usitatissimum, is a member of the genus Linum in the family Linaceae. It is a food and fiber crop cultivated in cooler regions of the world.As a percentage of total fat, flaxseeds contain 54% omega-3 fatty acids (mostly ALA), 18% omega-9 fatty acids (oleic acid), and 6% omega-6 fatty acids (linoleic acid); the seeds contain 9% saturated fat, including 5% as palmitic acid. Flaxseed oil contains 53% 18:3 omega-3 fatty acids (mostly ALA) and 13% 18:2 omega-6 fatty acids. Flaxseed is high in lignans (a type of plant compound known as polyphenols.) When you consume lignan precursors, bacteria in your gut convert the “plant” lignans into “human” lignans, including enterodiol and enterolactone, which have weak estrogenic activity.