Vigorous physical activity does not seem to affect the risk of developing Prostate cancer, but it may slow the progression of the disease in older men, new research suggests.

Previous studies have yielded conflicting results regarding the effects of exercise on Prostate cancer risk, Dr. Edward L. Giovannucci, from Harvard School of Public Health, and colleagues note. “However, many of the studies were not designed to examine physical activity in detail.”

To investigate the matter further, Giovannucci’s team analyzed data from nearly 50,000 men who participated in the US Health Professionals Follow-up Study. Over 14 years of follow-up, the subjects were asked detailed questions about exercise activity every other year.

Overall, 2892 new cases of prostate cancer were diagnosed, including 482 involving advanced disease. As noted, the overall risk of prostate cancer was not influenced by physical activity, the investigators report in the Archives of Internal Medicine.

However, among men 65 years of age and older, those engaging in at least 3 hours of vigorous physical activity per week were 67 percent less likely to be diagnosed with advanced disease than were inactive men.

For fatal cases of prostate cancer, the risk reduction was even more pronounced - 74 percent.

By contrast, no association between vigorous physical activity and slower disease progression was seen in younger men, the authors point out.

Among men with prostate cancer, the risk of advanced stage disease fell as physical activity rose, the findings show.

“Although the mechanisms still need to be understood, these findings suggest that vigorous activity could slow the progression of prostate cancer and might be recommended to reduce mortality from prostate cancer,” the team concludes, “particularly given the many other documented benefits of exercise.”

SOURCE: Archives of Internal Medicine, May 9, 2005.