Flax seeds are small, brown or golden seeds that come from the flax plant (*Linum usitatissimum*). They are rich in fiber, omega-3 fatty acids, and lignans, which are plant compounds with antioxidant properties. Flax seeds are often used as a dietary supplement for improving digestion, supporting heart health, and reducing inflammation. They can be eaten whole, ground, or used to extract flaxseed oil.