Tomatoes and Cancer

Eating tomatoes regularly may reduce the risk of prostate and several other cancers. Published research from Brigham and Women's Hospital and Harvard School of Public Health have shown that eating tomatoes and tomato products may help men reduce the risk of prostate cancer. Researchers carefully examined the full diet of 51,529 participants aged 40-75 years for more than 12 years. Men who consumed two-plus servings of tomato sauce per week had a 23% lower risk of total prostate cancer, and a 36% lower risk of metastatic prostate than participants who consumed less than one serving of tomato sauce per month. The findings appeared in the March 6, 2002 issue of the Journal of the National Cancer Institute.

The benefit of tomatoes in curbing prostate cancer and several other cancers have been reported by several researchers prior to the publication of this study. For example, both the Health Professional Follow-up Study and the Physicians' Health Study from Harvard University had shown that tomato consumption might cut significantly the risk of prostate cancer. Men who ate tomatoes 10 times a week reduced their risk for prostate cancer by almost half. All forms of tomato (raw, in ketchup, spaghetti sauce, tomato paste, soup, and salsa) had beneficial effect; however, tomatoes cooked in oil (such as in tomato sauce) appeared to be the most protective.

Tomatoes are also useful for those who are already diagnosed with the disease. Increased tomato consumption was found to be associated with a much less aggressive prostate cancer in men who were diagnosed with the disease. Tomatoes also reduced the risk for other types of cancers including lung, stomach, pancreatic, breast, cervical, colorectal, oral and esophageal cancers.

We do not know, for sure, how tomatoes ward off cancers. Many scientists believe that lycopenes, bioflavonoids that are closely related to beta carotene, present in tomatoes are natural cancer-fighting agents. Lycopenes give tomatoes its red color. Tomatoes are also rich in several nutrients including potassium, vitamin A, vitamin C, calcium and iron, in addition to lycopene. It is also possible that complex interactions among multiple components present in tomatoes contribute to its anticancer properties.

Tomatoes are one of the best sources for lycopine. Lycopine is an anti-oxidant that protects our body cells from oxidants that have been linked to cancer. Laboratory tests have shown that lycopene is twice as powerful as beta-carotene at neutralizing free radicals.

In a review published in the Feb 1999 issue of the Journal of National Cancer Institute, E Giovannucci M.D. (Harvard Medical School, Boston, MA) analyzed and compared the published studies regarding intake of tomatoes and tomato-based products and blood lycopene level in relation to the risk of various cancers. Out of 72 studies identified, 57 reported that tomato intake or blood lycopene level reduced the risk of cancer. 35 of these results were statistically significant.

Omer Kucuk, M.D., an oncologist from Wayne State University in Detroit, MI found that a lycopene supplement containing tomato extract may protect against prostate cancer. In a study presented in the 90th Annual Meeting of the American Association for Cancer Research (AACR) in 1999, Dr. Kucuk and colleagues followed 30 men with localized prostate cancer who were scheduled to undergo surgical removal of the prostate for three weeks. One group of patients was given an all-natural tomato lycopene supplement (a 15-milligram capsule twice daily), while another group was given dummy pills so researchers could compare results.

Following the surgical removal of their prostates, it was carefully analyzed to determine whether there were any differences between the two groups studied. Well, the results stunned many doctors.

A key marker for prostate cancer (PSA or prostate specific antigen) declined by 15 percent in patients taking the lycopene tomato extract. In the control group not taking lycopene, that marker increased by 15 percent. When surgeons removed the prostate glands, they found that patients taking lycopene had smaller tumors and that those tumors were more often confined to the prostate. (In other words, lycopene prevented the cancer from spreading to the surrounding tissue and organs.)

In analyzing the results, researchers observed that in the lycopene-treated group, 73 percent had organ-confined prostate cancer compared to only 18 percent in the control group. Eighty percent had tumors with a volume less than or equal to 4 cubic centimeters in the lycopene group compared to only 45 percent in the control group. This suggested that the group treated with lycopene had tumors that became less malignant.

This study may indicate that nutritional intervention can protect men against prostate cancer before it poses a threat to their lives, if it is detected early enough. Many scientists, however, pointed out to the small size of the sample involved in the study and advice caution.

Researchers from the University of Illinois at Chicago have conducted a similar study with 32 African American male patients on tomato regimen and seven others in the control, all diagnosed with prostate cancer awaiting surgery.
The test patients were given a daily dish of pasta and tomato sauce that delivered 30 milligrams of lycopene.

After three weeks in the tomato diet, the amount of lycopene in their prostate tissue tripled, their PSA dropped by 17.5 % and DNA damage was decreased in the men's white blood cells. The seven controls who did not eat tomato sauce had a higher oxidative damage in their prostates. Unlike Dr. Kucuk's trial, there was no reduction in the tumors.

The residents from southern Mediterranean countries, including Italy and Greece, have a low incidence of prostate cancer. Coincidentally, in these countries, the tomato consumption is high, another proof for the effectiveness of tomato in combating prostate cancer.

I recommend that you incorporate generous amounts of tomato in your diet. It is nutritious; it tastes good and it is good for you. You can also eat other fruits and vegetables high in lycopene such as pink grapefruit, guavas, and papayas. Lower the amount of fatty foods in your diet. A high-fat diet has been linked to a higher risk of contracting cancer. Exercise regularly. Studies have suggested that people who exercise regularly are at lower risk for cancer.