Lycopene

About Lycopene

Lycopene is a red carotenoid hydrocarbon responsible for the color of tomatoes, watermelon, pink grapefruit, guava and papaya. Lycopene is an acyclic, highly unsaturated molecule with a long chain of conjugated double bonds, and unlike beta carotene it lacks the beta ionone ring needed for conversion to vitamin A, so it has no provitamin A activity. It is one of the most prevalent carotenoids in human blood and tissues, and it is an efficient quencher of singlet oxygen in laboratory tests. In fresh tomatoes it exists mainly in the all trans form; heating and processing break down cell walls and promote isomerization to cis forms, so cooked tomato products such as paste and sauce supply more bioavailable lycopene than raw tomatoes. Observational studies have linked higher tomato and lycopene intake with lower risk of prostate cancer and cardiovascular disease, but the evidence is inconsistent and randomized trials have not established a causal benefit. Very high intakes can cause lycopenemia, a harmless and reversible orange discoloration of the skin.