Lycopene is an open-chain unsaturated carotenoid that imparts red colour to tomatoes, guava, rosehip, watermelon and pink grapefruit. Lycopene is a proven antioxidant. Antioxidants neutralize free radicals, which may damage the body's cells.

In the body, lycopene was found in the liver, lungs, prostate gland, colon and skin. Epidemiological studies have shown that high intake of lycopene-containing vegetables is inversely associated with the incidence of certain types of cancer. For example, habitual intake of tomato products has been inversely associated with the risk of cancer of the digestive tract among Italians. In one six-year study by Harvard Medical School and Harvard School of Public Health, the diets of more than 47,000 men were studied. The tomato products (which contain large quantities of lycopene) showed a measurable relationship to reduce prostate cancer risk. As consumption of tomato products increased, levels of lycopene in the blood increased, and the risk for prostate cancer decreased. The study also showed that the heat processing of tomatoes and tomato products increases lycopene's bioavailability.

Ongoing preliminary research also suggests that lycopene is associated with reduced risk of macular degenerative disease, serum lipid oxidation and cancers of the lung, bladder, cervix and skin.