Tomatoes and tomato-containing foods are high in lycopene. In the Harvard study, the only tomato-based food that did not correlate with protection was tomato juice. In an unblinded, controlled trial, lycopene supplementation, but not tomato juice, effectively increased the body’s lycopene stores. These studies suggest that the lycopene present in tomato juice is poorly absorbed. However, other research indicates that significant amounts of lycopene from tomato juice can, in fact, be absorbed. Other foods that contain lycopene include watermelon, pink grapefruit, and guava.