Just like the wild salmon and sardines, tuna is rich in omega-3 fatty acids. Apart from keeping your skin looking younger and healthier, tuna can also prevent skin cancer. One of the omega-3 fats in fatty fish called EPA (eicosapentaenoic acid), has been proven to sustain collagen. Collagen, is a fibrous protein which helps keep the skin firm. Dermatologist and doctors recommend eating plenty of fatty fish each week. Apart from the omega-3 rich foods being great for your skin, they are also good for your heart and health.