Lycopene

Aside from tomatoes or tomato products like ketchup, it is found in watermelons, grapefruits, red guavas, and baked beans. In plants, algae, and other photosynthetic organisms, lycopene is an intermediate in the biosynthesis of many carotenoids, including beta-carotene, which is responsible for yellow, orange, or red pigmentation, photosynthesis, and photoprotection. Australia and New Zealand (registered as 160d), and the European Union (E160d). ==Structure and physical properties==

Lycopene is a symmetrical tetraterpene because it consists entirely of carbon and hydrogen and is derived from eight isoprene subunits. In human blood, various cis-isomers constitute more than 60% of the total lycopene concentration, but the biological effects of individual isomers have not been investigated. Carotenoids like lycopene are found in photosynthetic pigment-protein complexes in plants, photosynthetic bacteria, fungi, and algae. Dispersed lycopene molecules can be encapsulated into carbon nanotubes enhancing their optical properties. Efficient energy transfer occurs between the encapsulated dye and nanotube—light is absorbed by the dye and without significant loss is transferred to the nanotube. Encapsulation increases chemical and thermal stability of lycopene molecules; it also allows their isolation and individual characterization. Biosynthesis The unconditioned biosynthesis of lycopene in eukaryotic plants and in prokaryotic cyanobacteria is similar, as are the enzymes involved. Synthesis begins with mevalonic acid, which is converted into dimethylallyl pyrophosphate. This is then condensed with three molecules of isopentenyl pyrophosphate (an isomer of dimethylallyl pyrophosphate), to give the 20-carbon geranylgeranyl pyrophosphate. Two molecules of this product are then condensed in a tail-to-tail configuration to give the 40-carbon phytoene, the first committed step in carotenoid biosynthesis. Through several desaturation steps, phytoene is converted into lycopene. The two terminal isoprene groups of lycopene can be cyclized to produce beta-carotene, which can then be transformed into a wide variety of xanthophylls. ==Diet==

Consumption by humans Absorption of lycopene requires that it be combined with bile salts and fat to form micelles. tomatoes and tomato-based sauces, juices, and ketchup account for more than 85% of the dietary intake of lycopene for most people. 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 up to four times more bioavailable than in fresh tomatoes. Processed tomato products such as pasteurized tomato juice, soup, sauce, and ketchup contain a higher concentration of bioavailable lycopene compared to raw tomatoes. Cooking and crushing tomatoes (as in the canning process) and serving in oil-rich dishes (such as spaghetti sauce or pizza) greatly increases assimilation from the digestive tract into the bloodstream. Lycopene is fat-soluble, so the oil is said to help absorption. Gac has high lycopene content derived mainly from its seed coats. Cara Cara navel oranges, and other citrus fruit, such as pink grapefruits, also contain lycopene. Some foods that do not appear red also contain lycopene, e.g., baked beans. Adverse effects Lycopene is non-toxic and commonly found in the diet, mainly from tomato products. Lycopene may increase the risk of bleeding when taken with anticoagulant drugs. The discoloration is expected to fade after discontinuing excessive lycopene intake. ==Research and potential health effects==

A 2020 review of randomized controlled trials found conflicting evidence for lycopene having an effect on cardiovascular risk factors, whereas a 2017 review concluded that tomato products and lycopene supplementation reduced blood lipids and blood pressure. A 2015 review found that dietary lycopene was associated with reduced risk of prostate cancer, whereas a 2021 meta-analysis found that dietary lycopene did not affect prostate cancer risk. Other reviews concluded that research has been insufficient to establish whether lycopene consumption affects human health. Regulatory status in Europe and the United States In a review of literature on lycopene and its potential benefit in the diet, the European Food Safety Authority concluded there was insufficient evidence for lycopene having antioxidant effects in humans, particularly in skin, heart function, or vision protection from ultraviolet light. Although lycopene from tomatoes has been tested in humans for cardiovascular diseases and prostate cancer, no effect on any disease was found. The US Food and Drug Administration, in rejecting manufacturers' requests in 2005 to allow "qualified labeling" for lycopene and the reduction of various cancer risks, provided a conclusion that remains in effect : In a review of research through 2024, the US National Cancer Institute concluded that the FDA has not approved the use of lycopene as effective for treating any medical condition, including various types of cancer. ==See also==