Collagen is a protein produced by your body and it gives your skin elasticity, strength and smoothness. As you grow older, your body produces less collagen and therefore skin sags and wrinkles. However, you can introduce collagen into your body through a proper diet. Collagen rich foods include soy products and dark green vegetables. Soymilk and cheese have genistein that helps produce collagen. Have a daily dose of spinach, cabbage, collards or kale. These are packed with an anti-oxidant called lutein which has anti-aging properties. Regular consumption of these vegetables will ensure that your body produces enough collagen to help you retain your youthfulness.