Eating Certain Vegetables May Reduce the Risk of Prostate Cancer

27/08/07 The risk of prostate cancer may be reduced by consuming more than one serving per week of broccoli, cauliflower, and other cruciferous vegetables, according to Yale School of Medicine researchers.

A team led by Victoria Kirsh, formerly a doctoral student in the Department of Epidemiology & Public Health, reported in the Journal of the National Cancer Institute that men who ate broccoli, cauliflower, cabbage, Brussel sprouts, and turnips were 40 percent less likely to be diagnosed with aggressive prostate cancer compared to men whose diet included very little of these vegetables.

The research team evaluated the association between fruit and vegetable intake and subsequent risk of prostate cancer among over 29,000 men participating in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial.

"Our findings are encouraging in that we noted a pronounced decrease in risk of extraprostatic cancer (Stage III or IV tumors) associated with slightly more than one serving (one half cup) per week of cruciferous vegetables," Kirsh said. "Broccoli and cauliflower had especially strong inverse associations. Aggressive prostate cancer that has spread beyond the prostate is associated with poor prognosis, and therefore identification of potential dietary determinants of this disease is important."

The study found that men who consumed cauliflower more than once a week were 52 percent less likely to be diagnosed with extraprostatic prostate cancer compared to those who ate cauliflower less than once a month. Men who consumed broccoli more than once a week were 45 percent less likely to be diagnosed with aggressive prostate cancer. Previous studies have suggested that plant compounds called glucosinolates, found abundantly in broccoli, are powerful anticarcinogens.

The study was conducted within a randomized screening trial. All participants underwent PSA screening according to the same prescribed regimen. The researchers controlled health behaviors, including smoking, physical activity, supplement use, and other dietary factors. "Our findings require corroboration in additional studies that use aggressive prostate cancer as their endpoint," Kirsh said.

Nearly two million American men are living with prostate cancer. The National Cancer Institute and the Prostate Cancer Foundation estimate more than 218,000 men will be diagnosed with prostate cancer, and more than 27,000 men will die from the disease in 2007.

The study was funded by the Division of Cancer Prevention and Intramural Research Program, the National Cancer Institute, the National Institutes of Health, and the U.S. Department of Health and Human Services.

Kirsh conducted the study in collaboration with Susan Mayne, professor of epidemiology in the Division of Chronic Disease Epidemiology on behalf of the Prostate, Lung, and Colorectal and Ovarian Cancer Screening Trial. Other researchers included Ulrike Peters, Amy Subar, Nilanjan Chatterjee, Christine Johnson, and Richard Hayes.