Lycopene, an antioxidant most readily found in tomatoes can increase your skin's defense against the sun.  The most concentrated way to get your lycopene is by eating 4 tablespoons of tomato paste a day.  In a study performed by Doctor Oz, participants of a study increased their natural defense against the sun by 30% after eating tomato paste every day for 3 months.  Along with tomatoes, lycopene, is also found in watermelon and grapefruit and it is what gives these fruits their red color.  

Fit TV is airing a series called Truth About Food with Doctor Oz where 40 experiments are conducted to prove or disprove popular beliefs about food.  This study can be seen in show 1 of the series.