Broccoli and Other Vegetables Linked with Decreased Risk of Aggressive Prostate Cancer

Eating more cruciferous vegetables like broccoli and cauliflower is associated with a reduced risk of aggressive prostate cancer. Several studies have demonstrated an association between eating vegetables and a reduced risk of prostate cancer, but study results have not been consistent and many have not investigated the association among patients with aggressive prostate cancer.

Victoria Kirsh, Ph.D., of Cancer Care Ontario in Toronto and colleagues evaluated the possible association in 1,338 prostate cancer patients diagnosed in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Each of the men completed a 137-item food-frequency questionnaire. They found that eating fruits and vegetables was not associated with decreased prostate cancer risk in general. But greater consumption of dark green and cruciferous vegetables, especially broccoli and cauliflower, was associated with a decreased risk of aggressive prostate cancer.

"Aggressive prostate cancer is biologically virulent and associated with poor prognosis. Therefore, if the association that we observed is ultimately found to be causal, a possible means to reduce the burden of this disease may be primary prevention through increased consumption of broccoli, cauliflower, and possibly spinach," the authors write. This research was published recently in the Journal of the National Cancer Institute. Note: This story has been adapted from a news release issued by Journal of the National Cancer Institute.

No Strong Link Between Tomatoes And Reduced Cancer Risk, FDA Finds

A U.S. Food and Drug Administration (FDA) review has found only limited evidence for an association between eating tomatoes and a decreased risk of certain cancers, according to an article published online July 10 in the Journal of the National Cancer Institute.

The reviewers found no evidence that tomatoes reduced the risk of lung, colorectal, breast, cervical, or endometrial cancer. However, there was very limited evidence for associations between tomato consumption and reduced risk of prostate, ovarian, gastric, and pancreatic cancers. (Credit: Photo by Scott Bauer / Courtesy of USDA-ARS)

Several studies have reported an association between the consumption of tomatoes or lycopene, an antioxidant that gives tomatoes their red hue, and a decreased risk of some cancers, particularly prostate cancer. In order for foods and dietary supplements to be labeled with such health claims, the FDA must review and approve these claims based on the available scientific evidence. In a review article, Claudine Kavanaugh, Ph.D., of the FDA in College Park, Md., and colleagues describe the agency’s November 2005 evaluation of the scientific evidence linking tomatoes or tomato-based foods, lycopene, and reduced cancer risk.

Their review found no evidence that tomatoes reduced the risk of lung, colorectal, breast, cervical, or endometrial cancer. However, there was very limited evidence for associations between tomato consumption and reduced risk of prostate, ovarian, gastric, and pancreatic cancers. Based on this assessment, the FDA decided to allow qualified health claims for a very limited association between tomatoes and these four cancers. Their analysis found no credible evidence that lycopene, either in food or in a dietary supplement, was associated with reduced risk of any of the cancers evaluated. For prostate cancer, for example, the FDA issued this statement: “Very limited and preliminary scientific research suggests that eating one-half to one cup of tomatoes and/or tomato sauce a week may reduce the risk of prostate cancer. [The] FDA concludes that there is little scientific evidence supporting this claim.”

In one of the accompanying editorials, Paul Coates, Ph.D., of the National Institutes of Health in Bethesda, Md., discusses some of the issues the FDA had to contend with in conducting their review, such as the limited number of available clinical trials and the challenge of communicating to the public the subtleties of the FDA’s decision. “Neither of these concerns, however, diminishes the importance of using evidence-based review principles to evaluate important diet-health relationships. In fact, it may be argued that evaluating a diet-health relationship is precisely the circumstance in which systematic review techniques can be most appropriate and effective because they are transparent and objective, and the search and review strategies could be exactly reproduced by others,” Coates writes.

In the second editorial, Edward Giovannucci, M.D., Sc.D., of the Harvard School of Public Health in Boston suggests that the widespread use of PSA (prostate-specific antigen) screening may influence the data on the association between tomato and lycopene consumption and prostate cancer risk. “Given the complexities of studying the relationship between tomato or lycopene intake and prostate cancer risk, both in terms of the exposures and the outcome, one should not be too surprised that no firm conclusion of benefit would be made in the FDA review…Although it may be premature to espouse increased consumption of tomato sauce or lycopene for prostate cancer prevention, this area of research remains promising,” Giovannucci writes. Note: This story has been adapted from a news release issued by Journal of the National Cancer Institute.

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