Lycopene, found primarily in tomatoes, is a member of the carotenoid family, which includes beta-carotene and similar compounds found naturally in food, and has potent antioxidant capabilities.
Tomatoes and tomato-containing foods are high in lycopene. In the Harvard study, the only tomato-based food that did not correlate with protection was tomato juice. In an unblinded, controlled trial, lycopene supplementation, but not tomato juice, effectively increased the body’s lycopene stores. These studies suggest that the lycopene present in tomato juice is poorly absorbed. However, other research indicates that significant amounts of lycopene from tomato juice can, in fact, be absorbed. Other foods that contain lycopene include watermelon, pink grapefruit, and guava.
Tomatoes provide the best natural source of lycopene, but the benefits you receive from tomatoes may depend on how they’re prepared. According to research from Cornell University, the body absorbs lycopene more efficiently (and benefits from a higher antioxidant activity) when tomatoes are cooked, as opposed to eating them raw.
Dosage
The daily supplemental intake of 5mg lycopene is comparable to the usual daily carotenoid intake. The ideal intake of lycopene is currently unknown; however, the men in the Harvard study with the greatest protection against cancer consumed at least 6.5mg per day. Doses of up to 30mg daily by mouth have been reported in scientific studies.
The bioavailability of lycopene varies significantly depending on the administered matrix. Lycopene from tomato oleoresin capsules and tomato juice (processed tomatoes) was better absorbed from the intestine than lycopene from raw tomatoes.
Reactions
No adverse effects have been reported with the use of lycopene.
Lycopene can help with the following
Atherosclerosis
Lycopene has been used in connection with the prevention (only) of Atherosclerosis.
Weakened Immune System
Lycopene supplementation has been found to boost immune function in the elderly. In one trial, 15mg of lycopene per day increased natural killer cell activity by 28% in 12 weeks. [Proc Nutr Soc 1998;57:3A (abstr)]
Asthma
Lycopene helps reduce the symptoms of asthma caused by exercising. In one double-blind trial [Allergy December, 2000;55: pp.1184-9], over half of people with exercise-induced asthma had significantly fewer asthma symptoms after taking capsules containing 30mg of lycopene per day for one week compared to when they took a placebo.
Cancer / Risk - General Measures
A review of 72 studies [J Natl Cancer Inst 1999;91: pp.317-31] reported 57 associations between tomato intake or blood lycopene levels and decreased risk of cancer. Of these associations, 35 were statistically significant. The benefit was strongest for prostate, lung, and stomach cancers, although protective associations were also found for cancers of the pancreas, colon, rectum, esophagus, oral cavity, breast, and cervix. Because the data were from observational studies, a cause-and-effect relationship cannot be firmly established. However, the consistently lower risk of cancer associated with higher consumption of lycopene-containing tomatoes, provides a strong foundation for further research on lycopene.
One study found that for the 25% of people with the greatest tomato intake, the risk for cancers of the gastrointestinal tract was 30-60% lower, compared with those who ate fewer tomatoes. These reduced risks were statistically significant. [Int J Cancer 1994;59: pp.181-4]
Tomatoes are rich in lycopene, an antioxidant compound for which previous studies have suggested and intervention role in certain cancers. In that cancer cells employ the mechanism known as angiogenesis to connect to the body’s blood supply, Mridula Chopra, from the University of Portsmouth (United Kingdom), and colleagues observed that lycopene disabled the angiogenic ability of cancer cells. Writing that: “The anti-angiogenic effects of lycopene in the present study were shown at a concentration that should be achievable by dietary means,” the study authors conclude that: “These results extend our knowledge of one of the putative anti-cancer actions of lycopene.”
[Elgass S, Cooper A, Chopra M. “Lycopene inhibits angiogenesis in human umbilical vein endothelial cells and rat aortic rings.” Br J Nutr. 2011 Dec 6:1-9.]
Increased Risk of Coronary Disease / Heart Attack
In Europe, researchers have found a statistically significant association between high dietary lycopene and a 48% lower risk of heart disease. [Am J Epidemiol 1997;146: pp.618-26]
In another study, using data from the ongoing Women’s Health Study, researchers at the Brigham and Women’s Hospital (BWH) and Harvard Medical School followed more than 28,000 middle-aged and elderly women for nearly five years, collecting blood samples to measure plasma lycopene levels. At the beginning of the trial, none of the women had any form of heart disease. When the testing period was completed, 483 women were diagnosed with cardiovascular disease (CVD).
The compiled data showed that when the subjects were divided into quartiles – ranging from those with the lowest lycopene
level to those with the highest – the women in the upper three quartiles had a 50 percent reduction in the risk of CVD compared with women in the lowest quartile.
In their conclusion, the researchers note that even though the study clearly shows that lycopene concentrations are associated with a lower risk of CVD in women, further trials are needed with other groups, such as younger people or men, for instance. Nevertheless, this impressive result expands on a 2002 study conducted by BWH in which the results also strongly suggested that lycopene intake may offer significant protection against heart disease in women.
Increased Risk of Cervical Cancer
A study of women found that the 75% who ate the least amount of tomatoes had between 3.5 and 4.7 times the risk for cervical intraepithelial neoplasia – pre-cancerous changes of the cervix. [Int J Cancer 1991;48: pp.34-8] Other researchers have also reported evidence suggesting that high dietary lycopene may be linked to protection from cervical dysplasia. [Nutr Cancer 1998;31: pp.31-40]
Increased Risk of Prostate Cancer
A study conducted by Harvard researchers examined the relationship between carotenoids and the risk of prostate cancer. [J Natl Cancer Inst 1995;87: pp.1767-76] Of the carotenoids studied, only lycopene was clearly linked to protection. The men who had the greatest amounts of lycopene in their diet (6.5mg per day or more) showed a 21% decreased risk of prostate cancer compared with those eating the least. This report suggests that lycopene may be an important tool in the prevention of prostate cancer. This study also reported that those who ate more than ten servings per week of tomato-based foods had a 35% decreased risk of prostate cancer compared with those eating less than 1.5 weekly servings. When the researchers looked at only advanced prostate cancer, the high lycopene eaters had an 86% decreased risk (although this did not reach statistical significance due to the small number of cases).
Contrary to popular opinion, research suggests that there is no preferential concentration of lycopene in prostate tissue. [Am J Epidemiol 2000;151: pp.124-7 (review, discussion 128-30)] Although prostate cancer patients have been reported to have low levels of lycopene in the blood [Nutr Cancer 1999;33: pp.159-64], and lycopene appears to be a potent inhibitor of human cancer cells in test-tubes [Nutr Cancer 1995;24: pp.257-66], evidence is conflicting concerning whether an increased intake of tomato products is protective against prostate cancer. Some studies, like the one discussed above, have reported that high consumption of tomatoes and tomato products reduces risk of prostate cancer. Other studies, however, are inconclusive [Am J Epidemiol 2000;151: pp.119-23], and some have found no protective association.
Increased Risk of Breast Cancer
While preliminary evidence links dietary lycopene with protection from breast cancer [Cancer Causes Control 1998;9: pp.89-97], another study did not find this link. [Cancer Lett 1997;114: pp.251-3]
Fibroids
A study from Firat University in Turkey (in association with the University of Maryland and Detroit’s Karmanos Cancer institute) indicates that lycopene intake may provide another preventive benefit for women.
The Firat researchers used Japanese quails to assess the effects of lycopene on the development of benign tumors of the uterus called fibroid tumors. The quails were used in the trial because fibroid tumors occur naturally in this species.
For 10 months, half the quails received feed with lycopene added, while half received normal feed. In the lycopene group, half the quails received twice the amount of lycopene as the other half. At the end of the trial period, the lycopene group had half as many tumors as the normal-feed group. And among the lycopene quails, those receiving the double dose of lycopene had significantly fewer tumors than the birds that received less of the supplement. Further study is needed to determine if this benefit is seen in humans.
Male Infertility (Low Sperm Count)
A study performed in India showed that lycopene supplementation proved to be beneficial to couples who try for the first time to conceive but are not successful due to unspecified male infertility problems. In this study, 50 men with low sperm counts were selected to receive lycopene supplements twice per day for three months. Within nine months after starting the lycopene supplements, 36% of the couples were successful. Amongst the 50 men, 70% had an increase in sperm concentration and 58% had an increase in sperm motility.
Key
| May do some good |
| Likely to help |
Glossary
Carotenoid
A group of red, orange and yellow pigments found in plant foods and in the tissues of organisms that consume plants. Carotenoids have antioxidant activity and some, but not all, can act as precursors of vitamin A. Studies have shown that several carotenoids other than beta-carotene are potent antioxidants that provide profound health benefits. Because of this, the scientific community has now recognized the importance of natural mixed carotenoids including beta-carotene.
Beta-Carotene
The most abundant of the carotenoids, beta-carotene has strong provitamin A activity and is a stronger antioxidant than vitamin A. It is widely accepted today as a cancer preventative. It is found in leafy green and yellow vegetables, often missing in children's diets. Beta-Carotene is believed to be a superior source of Vitamin A because it is readily converted into a more active form of the substance: your body converts it to Vitamin A as needed.
Antioxidant
A chemical compound that slows or prevents oxygen from reacting with other compounds. Some antioxidants have been shown to have cancer-protecting potential because they neutralize free radicals. Examples include vitamins C and E, alpha lipoic acid, beta carotene, the minerals selenium, zinc, and germanium, superoxide dismutase (SOD), coenzyme Q10, catalase, and some amino acids, like cystiene. Other nutrient sources include grape seed extract, curcumin, gingko, green tea, olive leaf, policosanol and pycnogenol.
Milligram
(mg): 1/1,000 of a gram by weight.
Cancer
Refers to the various types of malignant neoplasms that contain cells growing out of control and invading adjacent tissues, which may metastasize to distant tissues.