Flax seeds

Flax seeds have a lot of health benefits. They include lignans, a type of polyphenol with antioxidant properties that may reduce the risk of chronic diseases including heart disease and breast cancer.

They're also a good source of alpha-linolenic acid, an omega-3 fatty acid (ALA). A diet high in omega-3 fats helps in the maintenance of a healthy skin membrane by keeping it moisturized and plump. Women who took flax seeds or flax oil for 12 weeks showed increased hydration and smoother skin in high-quality studies conducted between 2009 and 2011. However, more recent studies are required.