In a 100-gram serving, flaxseed contains high levels (> 19% of the Daily Value, DV) of protein, dietary fiber, several B vitamins, and dietary minerals. Ten grams of flaxseed contains one gram of water-soluble fiber (which lowers blood cholesterol) and three grams of insoluble fiber (which helps prevent constipation). Flax contains hundreds of times more lignans than other plant foods. Flaxseeds are especially rich in thiamine, magnesium, potassium, and phosphorus (DVs above 90%).
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.