James Hébert, chair of the Department of Epidemiology and Biostatistics in The Norman J. Arnold School of Public Health, was principal researcher of study conducted recently in Massachusetts that revealed a clear link between diet, exercise, and biochemical markers for prostate cancer.

"The 10 men in our study had their prostates removed following a diagnosis of prostate cancer. After an average period of about three years during which there was no evidence of disease, the men subsequently were found to have rising levels of prostate-specific antigen (PSA), an indication that their prostate cancer had recurred and was spreading," Hébert said.

A high-fiber diet, consisting of brown rice, beans, and fresh vegetables, while avoiding meat and other sources of fat, coupled with mindfulness meditation and exercise was associated with a slower rate at which PSA levels were rising in 8 of the 10 men (average doubling time increased from about six months to a year and a half), and with absolute decreases in PSA levels in three of the men.

The study, to be published in the December 2001 issue of the Journal of Urology, suggests that prostate cancer is responsive to high-fiber, low-fat diets and exercise and might even be prevented by such measures.

Hébert and colleagues at the Veterans Administration Hospital in Columbia have applied for a grant from the U.S. Army to conduct a larger randomized study with V.A. Hospital patients.

"South Carolina has one of the highest rates of prostate cancer in the world, so this would be a logical place to conduct such a study," Hébert said. In the larger, more rigorous study proposed, "we might very well find that diet and exercise is a good preventive model for prostate cancer as well as an effective therapy for those who are fighting the disease."

Exactly how the diet/exercise combination works to decrease prostate cancer levels isn't clear, although other studies have shown that high-fiber, low-fat diets can increase the excretion of harmful waste products in the blood, alter hormone levels, and affect immune response.

"Our research group was also the first to show that excessive dietary fat can blunt the effectiveness of natural killer cells, the body's main front-line defense against cancer," Hébert said. About 40 percent of men whose prostate glands are removed because of prostate cancer experience a recurrence of the disease within 10 years.

Hébert's initial study seemed to show that the rate at which the returned cancer accelerates can be slowed or even reversed by diet and exercise. The proposed study, to be conducted in the Midlands, will provide more definitive evidence for men, their families, and health professionals who care for them.

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