likopen

Likopen, commonly known as lycopene, is a natural carotenoid pigment that gives red color to tomatoes, watermelons, pink grapefruit, papaya, and other fruits and vegetables. It functions as an antioxidant in humans and is a non-provitamin A carotenoid.

Chemically, lycopene is an acyclic molecule composed of a long chain of conjugated double bonds. It is fat-soluble, and its absorption from the diet is enhanced by dietary fats. After absorption, lycopene is transported in lipoproteins and accumulates in tissues such as the liver and adipose tissue; plasma levels reflect intake and can be measured by laboratory methods.

Key dietary sources include tomatoes and tomato products (sauce, paste, juice), watermelon, pink grapefruit, papaya, guava, apricot, and red peppers. Typical intakes vary by population, but food-based lycopene is commonly consumed via tomato-containing foods.

Bioavailability is influenced by processing and cooking. Heat processing and mechanical processing increase lycopene release from the plant matrix, and adding oil can markedly increase absorption.

Health effects: Lycopene acts as an antioxidant and may influence biomarkers of oxidative stress and inflammation. Observational studies have suggested associations with lower risk of some cancers and cardiovascular diseases, particularly prostate cancer; however randomized trials have produced mixed or inconclusive results. There is not yet consistent evidence that lycopene supplementation prevents disease.

Safety: Lycopene from food is considered safe; there is no established upper intake level. Very high-dose supplements are generally well tolerated but can cause gastrointestinal symptoms in some people and may interact with certain medications; it is usually preferable to obtain lycopene from foods rather than supplements.