Cooking tomatoes—such as in spaghetti sauce—makes the fruit heart-healthier and boosts its 

 cancer-fighting ability. All this, despite a loss of vitamin C during the cooking process, say Cornell food scientists. The reason :cooking substantially raises the levels of beneficial compounds called phytochemicals. Heat processing actually enhanced the nutritional value of tomatoes by increasing the lycopene content—a phytochemical that makes tomatoes red—that can be absorbed by the body, as well as the total antioxidant activity. The research dispels the popular notion that processed fruits and vegetables have lower nutritional value than fresh produce.