Lycopene is a naturally occurring chemical that gives fruits and vegetables a red color. It is one of a number of pigments called carotenoids. Lycopene is found in watermelons, pink grapefruits, apricots, and pink guavas. It is found in particularly high amounts in tomatoes and tomato products. In North America, 85% of dietary lycopene comes from tomato products such as tomato juice or paste.

People take lycopene for preventing heart disease, "hardening of the arteries" (atherosclerosis); and cancer of the prostate, breast, lung, bladder, ovaries, colon, and pancreas. Lycopene is also used for treating human papilloma virus (HPV) infection, which is a major cause of uterine cancer. Some people also use lycopene for cataracts and asthma. Lycopene is a powerful antioxidant that may help protect cells from damage. This is why there is a lot of research interest in lycopene’s role, if any, in preventing cancer. Lycopene has been linked with reduced risk of prostate and cervical cancers, as well as supporting cardiovascular health. Recent findings indicate that lycopene is an important part of the human organism's natural defense mechanism that protects us from harmful oxidizing agents.

What is Lycopene?

Lycopene is a carotenoid responsible for the red color of the tomato, watermelon and pink grapefruit. In plants, lycopene is similar to other carotenoids, serving as a light-absorbing pigment during photosynthesis and protecting cells against photosensitization. It has a unique long chain molecular structure containing 13 double bonds, more than any other carotenoid. This configuration is responsible for lycopene's special ability to neutralize free radicals. Among the carotenoids, it is the most efficient quencher of singlet oxygen free radicals. Lycopene is an acyclic isomer of beta-carotene. Beta-carotene, which contains beta-ionone rings at each end of the molecule, is formed in plants, including tomatoes, via the action of the enzyme lycopene beta-cyclase. Lycopene is a 40 carbon atom, open chain polyisoprenoid with 11 conjugated double bonds. Lycopene tends to concentrate in bodily tissues at higher amounts than all other carotenoids, especially in the testes and adrenal glands.

How is it Made?
The 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 twenty carbon geranylgeranyl pyrophosphate. Two molecules of this product are then condensed in a tail-to-tail configuration to give the forty 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.

Where is it Found?
The name of lycopene is derived from the tomato's species classification, Lycopersicon esculentum. Highest natural concentrations of lycopene in food are found not in tomatoes, but in watermelon. Watermelon contains 15 to 20 milligrams of lycopene per 2-cup serving. Almost all dietary lycopene is derived from tomato products. Lycopene content of tomatoes can vary significantly, depending on type of tomato and ripening. One cup (240 mL) of tomato juice provides about 23 mg of lycopene. Processing raw tomatoes using heat (in the making of tomato juice, tomato paste or ketchup, for example) actually changes the lycopene in the raw product into a form that is easier for the body to use. The lycopene in supplements is about as easy for the body to use as lycopene found in food.

Benefits / Uses
The health benefits of lycopene are attributed to its ability to protect cells against oxidative damage. Lycopene has the ability to quench singlet oxygen (more so than beta-carotene), to trap peroxyl radicals, to inhibit the oxidation of DNA, to inhibit lipid peroxidation, and in some studies, to inhibit the oxidation of low-density lipoprotein (LDL). It helps prevent degenerative diseases by donating its electrons to oxygen free radicals thus quenching and neutralising them before they can damage cells. Free radicals are molecules that have at least one unpaired electron. By donating an electron lycopene can stabilise the free molecule.

Fighting cancer - Because lycopene is a potent antioxidant and seems to inhibit growth of cancer cells, it is logical that a higher intake of this carotenoid may indeed be associated with reduced incidence of cancer. Several studies suggest that eating vegetables rich in lycopene, such as tomatoes or tomato-based products, may reduce the risk of getting breast, cervical, gastrointestinal, colorectal, lung and prostate cancer. Carotenoids work to protect against cancer and aging-related diseases by acting as an antioxidant to counteract damaging effects of free radicals in tissues. Lycopene is one of the major carotenoids found in human blood and tissues, and is found primarily in the testis, adrenal glands, liver, prostate, breast, colon, and lung.

Preventing heart diseases - Lycopene is found to prevent oxidation of lipids and low density lipoprotein cholesterol (LDL), and reduced the risk of a person developing atherosclerosis and coronary heart disease. Lycopene helps prevent heart disease through this same antioxidant mechanism via an inhibition of oxidative damage to LDL cholesterol. The strong lipid antioxidant properties of lycopene make it particularly effective in blocking LDL oxidation and protecting against free radical activity on the arterial wall. Lycopene inhibits cholesterol synthesis and HMG-CoA (hydroxymethylglutaryl coenzyme A) reductase activity, and upregulates LDL receptor activity in macrophages. Daily consumption of tomato products providing at least 40 mg of lycopene substantially reduces low-density lipoprotein (LDL) oxidation. High LDL oxidation is associated with increased risk of atherosclerosis and coronary heart disease.

Keeping skin healthy - Lycopene may help reduce the damage to the skin caused by ultraviolet light during and after sun exposure. Skin exposure to ultraviolet radiation is responsible for sunburn, tanning, premature aging and skin cancer. These effects are partly due to the formation of oxygen free radicals. Lycopene has the ability to quench free radicals, which are highly reactive compounds that are formed in the body from normal metabolism, as well as from environmental pollutants and radiation. xposure to certain types of UV radiation can cause damage to DNA (the genetic material of the body) and increase the risks of skin cancer. The powerful antioxidant action of lycopene helps to prevent the oxidation of serum lipids, thus promoting arterial health.

Dosage
There is no recommended daily dosage for lycopene. The major epidemiological studies have shown that those who ate at least ten servings of tomato products per week, averaging about 6.5 mg of lycopene per day, had the greatest reduction in cancer risk. Research shows that drinking two cups (about 540 ml) of tomato juice per day provides about 40 mg of lycopene. This is the amount recommended to significantly reduce the oxidation of LDL cholesterol, according to one human dietary intervention study. Lycopene supplements are available as oleoresin preparations, phospholipid preparations and in oils, such as medium chain triglycerides. Doses range from 5 to 15 milligrams daily.

Possible Side-Effects / Precautions / Possible Interactions
Lycopene is likely safe when taken by mouth in appropriate amounts. Daily supplements containing 30 mg of lycopene have been used safely for up to 8 weeks.

Special Precautions & Warnings:
Pregnancy and breast-feeding: Lycopene is likely safe when taken in amounts commonly found in foods. However, not enough is known about the safety of using lycopene supplements during pregnancy or breast-feeding. If you are pregnant or breast-feeding, avoid using lycopene in amounts greater than those typically found in foods.
Prostate cancer: Developing research suggests lycopene might worsen established prostate cancer. Until more is known, avoid lycopene if you have a prostate cancer diagnosis.

Research Studies / References