Flax seeds (Linum usitatissimum) are a rich source of omega-3 fatty acids (ALA), lignans (plant phytoestrogens), and both soluble and insoluble fiber. Harvard Health notes that the ALA in flax is linked to reduced heart disease risk. Its high fiber content can significantly lower cholesterol and stabilize blood sugar. For hair and skin, flaxseed oil’s anti-inflammatory ALA may help reduce dryness and flakiness, and its antioxidants support skin health. People commonly use ground flax as an egg substitute or fiber supplement.