Tomato and cancer prevention has been a controversial topic for over a decade. Although some studies have shown its anticancer properties the FDA prohibits any treatment or prevention claim. This article covers not only tomatoes but also lycopene and prostate cancer treatment as well as the findings of the latest studies on tomato and breast cancer.
Tomato is a species of herbaceous plants native to northwestern South America. It is widely consumed as a vegetable, raw or cooked. It has become an essential element of food in many countries, including the United States. Tomatoes are rich in water (93-95%) and very low in calories, about 17 kcal per 100 grams, yet very rich in minerals and vitamins: A, C and E. Ripe tomatoes also contain carotenoids, including beta-carotene which acts as a provitamin A.
Tomato and Cancer
Tomatoes have been traditionally used in herbal medicine due to its carotenoid and antioxidant contents, especially lycopene, known for its anti-cancer properties and prevention against cardiovascular disease in particular. Note that lycopene is more easily assimilated by eating cooked tomatoes the fact that cooking releasing nutrients by breaking the vegetable cells.
Tomato and Prostate Cancer
Prostate cancer is one of the most frequently diagnosed cancers among men in the United States. Several studies have shown that frequent or regular consumption of tomato derivatives could have a protective effect against the tumor. The compounds in the tomato-based products would increase the resistance to oxidation of cells and thus would prevent the development of this serious medical condition. According to the results of a meta-analysis, the biggest consumers of tomatoes and its derivatives decrease by 10% to 20% their risk of developing prostate cancer compared to men who ate little or none. Tomato and prostate cancer prevention also observe in people most at risk.
Tomato and Breast Cancer and Other Cancers
According to twenty recent studies, high consumption of lycopene, a major antioxidant in tomatoes, would be linked to a lower incidence of breast cancer, lung cancer and stomach tumor. The consumption of tomatoes and lycopene could have a protective effect on the incidence of cancers of the pancreas, colon, rectum, esophagus, oral cavity, and cervix. More studies are however required to define the role of lycopene in the prevention of various types of cancer, as well as that of other compounds present in the tomato, such as carotenoids.
Lycopene and Cancer
Tomatoes contain antioxidants, especially carotenoids; the most abundant is lycopene, a pigment that gives it its bright red color. The antioxidant activity of tomato is also ensured by various phenolic compounds. These compounds would protect healthy cells from damage caused by free radicals, and prevent the development of cardiovascular disease, certain cancers and other diseases related to aging.
Lycopene and Prostate Cancer
Lycopene is found in particularly high concentration in the prostate tissue. According to several studies, this compound helps to prevent prostate cancer. High concentrations of lycopene in the blood have been associated with lower incidences of this type of tumor. By cons, taking lycopene supplements was not associated with the same effects in the body. The researchers therefore conclude that lycopene is not the single compound responsible for these effects. It would act in synergy with other compounds in tomatoes, including other carotenoids.
Tomatoes and tomato products are the main sources of lycopene in the North American diet, providing 85% of this carotenoid. In addition to its important antioxidant, the vegetable has cholesterol-lowering effects, anti-inflammatory, as well as the ability to prevent the proliferation of certain types of cancerous cells. Although current data are insufficient to recommend a daily intake of lycopene, studies indicate that consumption of more than 6 mg of lycopene per day, about 2 raw tomatoes or ½ glass of tomato juice, could lead to the benefits.
Tomatoes and tomato derivatives contain different amounts of lycopene according to the transformation process they have undergone: cooking, grinding, homogenization, etc. The bioavailability of lycopene, that is its absorption in the body, increases when it exchanges structure or when releases from the cells which contain it. Certain products significantly increase the concentration of the pigment in the blood. For example, it would require consuming up to 13 times more than fresh tomatoes or tomato juice to increase equivalently blood levels of lycopene provided by certain Industrial by-products. Turning off fresh tomatoes into small pieces and eat them with healthy fat would improve the absorption of carotenoids in the blood. However, the absorption capacity in the body differs from one individual to another.
FDA (Food and Drug Administration)
Following a request from supplement industry that wanted to promote anticancer claims of lycopene supplements, the Food and Drug Administration (FDA) made a comprehensive analysis of the scientific data on the food source of lycopene and lycopene supplements. In November 2005, on the basis of this information, the FDA refused to lycopene supplement manufacturers the right to display anticancer allegations due to insufficient evidence.
The vast majority of data on the association between tomato consumption and prevention of certain cancers are epidemiological studies which, according to the FDA, do not allow to draw clear conclusions about the preventive effect of lycopene-rich foods.
However, the FDA has a very nuanced claim on certain products from tomatoes. In the United States, manufacturers can claim the potential preventive effects of the consumption of tomatoes (or tomato products) against prostate cancer, but they have to clearly state: “FDA concludes that there is little scientific evidence to support this allegation.”
WHO (World Health Organization)
In 2007, the global network of the World Cancer Research Fund (WCRF) released its second report on the relationship between diet, physical activity and cancer risk. The report is based on analysis of 500 thousand scientific studies, of which only 7,000 were selected by an international committee of experts to draw up the report. The researchers conclude that there is a sufficient body of evidence to support the preventive effects of foods containing lycopene, especially tomato and its derivatives on prostate cancer. According to the report, the effect increases with dose and lycopene is best absorbed when food is cooked and shredded.
Lycopene and Prostate Cancer Treatment
Prostate cancer treatment is an interesting topic worldwide. According to the WCRF report in 2007, lycopene slow down the development of prostate cancer and the effect would be more pronounced in the more advanced stages of cancer.
In 2009, a summary of the use of lycopene and prostate cancer treatment indicates that it is impossible to comment on this purpose given the current state of the data. By cons, WHO acknowledges lycopene alleviate the symptoms associated with prostate cancer, such as pain and trouble urinating. On the other hand, it could inhibit the progression of cancer, when combined with soy isoflavones (compounds that are capable of exerting estrogen-like effects), as supplements or foods, suggests the report. The researchers also have hypothesized that other compounds of the tomato can act in conjunction.
Lycopene and Breast Cancer
Lycopene and Breast Cancer treatment is also highly controversial. Other claims allowed by FDA apply to potential prevention of stomach cancer, ovarian cancer, Breast Cancer, and pancreatic cancer. However, they must be accompanied by a statement that the preventive effect of tomatoes in this area is “unlikely or highly unlikely.” This supports the conclusions of WCRF who reported no significant effect of lycopene on other types of cancer.
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