Lycopene
Lycopene is the source of the red colouring of tomatoes, red peppers, red grapefruit, pink guava, papaya, rosehip and watermelon. It is a carotenoid with powerful anti-oxidant properties that cannot be made by our bodies, and so must be obtained in food.
In the body, lycopene is deposited in the liver, lungs, prostate gland, colon and skin. Its concentration in body tissues tends to be higher than all other carotenoids. Some organs, such as the testes and adrenal glands, store higher levels of lycopene than do other organs or tissues.
For years, it was ignored by nutritionists because it cannot be converted into the essential vitamin A.In recent years however, lycopene has been shown to have major protective effects throughout the body, including those for degenerative diseases, cholesterol, and healthy vision.
Dietary consumption of lycopene (mostly from tomato products) has been associated with a lowered risk of prostate cancer. Men with higher levels of lycopene in their blood had statistically significant lower rates of cancer than did men with lower blood levels of lycopene. Studies have also shown that men who eat more lycopene-rich foods have less heart disease.
Ongoing research suggests that lycopene can reduce the risk of macular degenerative disease, serum lipid oxidation and cancers of the lung, bladder, prostate, cervix and skin, and helps prevent LDL cholesterol oxidisation, which is contributory to heart disease and strokes.
Unlike other fruits and vegetables, where nutritional content such as vitamin C is diminished upon cooking, processing of tomatoes increases the concentration of bioavailable lycopene. Lycopene in tomato paste is four times more bioavailable than in fresh tomatoes. Thus processed tomato products such as pasteurized tomato juice, soup, sauce, and ketchup contain the highest concentrations of bioavailable lycopene.
In the future, plants may not be the only source of carotenoids such as lycopene. The commercial production of natural carotenoids through microbial biotechnology is already established and expanding, mainly through the exploitation of algae that can synthesize large quantities of carotenoids.