ψ, ψ-carotene, all-trans lycopene, Lyc-o-Mato, Lycopersicon, Lycopersicon esculentum, LycoRed, prolycopene, psi, psi-carotene, solanorubin, tangerine tomatoes, tomato, tomato paste.
Lycopene is a carotenoid present in human serum and skin as well as the liver, adrenal glands, lungs, prostate and colon. Lycopene has been found to possess antioxidant and antiproliferative properties in animal and laboratory studies, although activity in humans remains controversial.
Numerous studies correlate high intake of lycopene-containing foods or high lycopene serum levels with reduced incidence of cancer, cardiovascular disease, and macular degeneration. However, estimates of lycopene consumption have been based on reported tomato intake, not on the use of lycopene supplements. Since tomatoes are sources of other nutrients, including vitamin C, folate, and potassium, it is not clear that lycopene itself is beneficial.
There is no well established definition of "lycopene deficiency," and direct evidence that repletion of low lycopene levels has any benefit is lacking.
Laboratory research suggests that lycopene, like other carotenoids, may have antioxidant properties. However, it is not clear if lycopene has these effects in the human body. Results of different studies do not agree with each other and better research is needed before a firm conclusion can be drawn.
Asthma caused by exercise:
Laboratory research suggests that lycopene, like other carotenoids, may have antioxidant properties. It has been suggested that antioxidants may be helpful in the prevention of asthma that is caused by exercise. There is limited, poor-quality research in this area and further evidence is needed before a recommendation can be made.
Atherosclerosis (clogged arteries) and high cholesterol:
It has been suggested that lycopene may be helpful in people with atherosclerosis or high cholesterol, possibly due to antioxidant properties. Several studies have been published in this area, most using tomato juice as a treatment. Results have not agreed with each other, and this issue remains unclear.
Benign prostate hyperplasia (BPH):
Patients diagnosed with BPH or enlarged prostate are at increased risk of developing prostate cancer and may benefit from taking lycopene supplements. Initial evidence suggests that lycopene may help prevent disease progression in BPH. Further studies are necessary before lycopene may be recommended.
Breast cancer prevention:
Research in animals and observations of large human populations have examined the relationship between developing breast cancer and tomato intake or lycopene levels in the body. The evidence in this area is not clear, and further studies are needed before a firm conclusion can be drawn.
Cancer prevention (general):
Studies have examined large populations to identify the lifestyle factors that affect health. Many of these studies suggest a link between diets high in fruits and vegetables and a decreased risk of developing cancer. However, it is not entirely clear which foods are most beneficial, or if reduced cancer is due to other (non-dietary) aspects of a "healthy lifestyle."
Cervical cancer prevention:
Observations of large human populations suggest possible benefits of tomato product intake in preventing cervical cancer. However, other studies report no benefits. Research that specifically studies lycopene supplements is lacking.
Coronary artery disease (prevention):
Lycopene may prevent cardiovascular diseases including hypertension (high blood pressure) and coronary artery disease. There is some evidence that the lycopene-containing supplement LycoRed may reduce total cholesterol and low-density lipoproteins (LDL or "bad cholesterol"), while increasing high-density lipoproteins (HDL or "good cholesterol").
Eye disorders (age-related macular degeneration prevention, cataracts):
Based on antioxidant properties observed in laboratory studies, lycopene has been suggested as a preventive therapy for age-related macular degeneration (AMD) and cataracts. However, recent studies have not found a clear benefit.
Gastrointestinal tract and colorectal cancer prevention:
Multiple studies have investigated whether intake of tomatoes or tomato-based products helps prevent digestive tract cancers, including oral, pharyngeal, esophageal, gastric, colon, and rectal. Results have been inconsistent with some studies reporting significant benefits and others finding no effects. Research that specifically studies lycopene supplements is limited, and more research is needed in this area before a firm conclusion can be drawn.
There is some evidence that lycopene, administered systemically, may be an effective treatment for gingivitis. Further studies are needed to support these early findings and to examine lycopene in combination with other gingivitis treatments.
High blood pressure:
There is some evidence that short term treatments of lycopene may reduce blood pressure. More research is needed, especially to examine the long-term effects of lycopene on blood pressure.
High blood pressure associated with pregnancy (pre-eclampsia):
Based on early study, lycopene may reduce the development of pre-eclampsia and intrauterine growth retardation in women having their first child. Further research is needed to confirm these results.
Based on early study, taking lycopene seems to have a role in the management of idiopathic male infertility. Further research is needed to confirm these results.
There is very limited evidence that lycopene supplements may not reduce the risks of renal cell cancer, which affects the kidneys. Additional research is needed.
Lung cancer prevention:
Several studies observing large populations report a lower risk of developing lung cancer in people who regularly eat tomatoes. However, other studies report no benefits of tomato consumption. Research that specifically studies lycopene supplements is lacking.
Ovarian cancer (prevention):
Based on population studies, lycopene intake in food seems to decrease the risk for ovarian cancer. However, research that specifically examines lycopene supplementation and ovarian cancer risk is lacking.
Studies of large populations report mixed results as to whether eating tomatoes/tomato-based products reduces the risk of developing prostate cancer. There is some evidence that lycopene may slow the progression of prostate cancer. Research that specifically studies lycopene supplements is limited.
Lycopene in combination with other carotenoids, such as beta-carotene, vitamins C and E, selenium, and proanthocyanidins, may help in reducing sunburn.Selected protective effects from UV rays have been observed in small, short-term studies. More research is needed before a firm conclusion can be drawn.
It has been proposed that lycopene and other carotenoids, such as beta-carotene, may stimulate the immune system. However, several studies of lycopene supplements and tomato juice intake in humans report no effects on the immune system.
Lung function after exercise:
A daily dose of lycopene for one week does not seem to affect lung function after exercise and does not provide any protective effect against clinical difficulty in breathing in young athletes.
There is no proven effective medicinal dose of lycopene or lycopene-rich vegetables. A common dosing range is 2-30 milligrams of lycopene taken daily by mouth for up to six months. Commercially available products such as Lyc-O-Mato® and Lyco-O-Pen® have been studied for various conditions as have lycopene oleoresin capsules.
There is not enough scientific evidence to recommend the use of lycopene supplements in children.
Avoid lycopene in individuals with a known allergy/hypersensitivity to lycopene or tomatoes.
The safety of lycopene supplements has not been thoroughly studied. Review of available scientific literature finds tomatoes, tomato-based products, and lycopene supplements generally well tolerated. However, rare reports of diarrhea, nausea, stomach pain or cramps, gas, vomiting, and loss of appetite have been reported. Tomatoes and tomato-based products may be acidic and irritate stomach ulcers. Lycopene has been associated with death from a cancer-related hemorrhage, although causality is unclear.
There is not enough scientific research to recommend the use of lycopene supplements during pregnancy and breastfeeding. Amounts of lycopene found in foods are usually assumed to be safe. Tomato consumption has been shown to increase lycopene concentrations in breast milk and plasma of breastfeeding women.
Some drugs that lower cholesterol levels in the blood may also reduce the levels of carotenoids such as lycopene. Examples of cholesterol-lowering drugs include "statin" drugs like lovastatin (Mevacor®) or atorvastatin (Lipitor®), cholestyramine (Questran®, Prevalite®, LoCHOLEST®), or colestipol (Cholestid®). It is unknown if replacing lycopene levels with supplements has any benefit in people using these drugs. Some research suggests that lycopene may add to the cholesterol-lowering effects of statin drugs.
It is proposed that nicotine (cigarette smoking) and alcohol may lower lycopene levels in the body, although this has not been proven.
Based on human study, tomato-based foods may prevent platelet aggregation and thrombosis. Theoretically, lycopene may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).
Lycopene may interact with drugs taken for cancer or high blood pressure. Lycopene may also interact with drugs that alter the body's immune response.
In theory, lycopene may interact with fertility treatments, but this potential interaction has not been thoroughly studied.
Studies report mixed effects of taking lycopene with beta-carotene. Some studies report higher levels of lycopene, while others note no change or decreased levels. Canthaxanthin has been shown to reduce lycopene uptake from dietary sources and its use may result in decreased lycopene levels in the blood.
Laboratory studies suggest possible interactions between lycopene and other vitamins or supplements, although the significance of these interactions in the human body is not known. Examples include increased antioxidant effects when lycopene is combined with lutein or decreased growth of cancer-like cells when used with vitamin D or vitamin E.
Red palm oil may increase blood levels of lycopene.
Based on human study, tomato-based foods may prevent platelet aggregation and thrombosis. Theoretically, lycopene may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.
Lycopene may also interact with herbs or supplements taken for cancer, high blood pressure, or high cholesterol and those that alter the body's immune response.
It has been suggested that when lycopene and soy isoflavones are taken together, the potential benefits of both supplements may be negated.
In theory, lycopene may interact with herbs that affect fertility, but this potential interaction has not been thoroughly studied.