Exercise may reduce the risk of prostate cancer in older, white men, a new study suggests.
In the study, moderately or highly active white men in their 60s were 53 percent less likely to have a prostate cancer biopsy test positive for cancer compared with those who were not very active or who were sedentary.
However, no link was found between exercise and prostate cancer risk for black men, a group at particularly high risk for prostate cancer. African-American men are more likely to be diagnosed with prostate cancer (and ultimately die from it) than men from other racial groups, according to the Centers for Disease Control and Prevention.
Future research should investigate why exercise does not lower the risk of prostate cancer in black men in the same way it does for white men, though differences in genetics or hormones may play a role, the researchers say.
However, some experts were critical of the study, which they say is too small to really draw any conclusions about the role exercise plays in prostate cancer.
"Maybe there is some effect of exercise," but the study is so small "that one really couldn’t establish any strong conclusions about race, or set recommendations based on this," said Dr. Steven Clinton, an oncologist at the Ohio State University James Cancer Hospital.
The study is published online today (Feb. 11) in the journal Cancer.
The study involved 307 men (164 were white and 143 were black) who had a biopsy to test for prostate cancer. All the men also answered questions designed to gauge their weekly level of physical activity. One hundred twenty-five men were diagnosed with prostate cancer based on the results of the biopsy. Of these, 45 percent were black.
The link between exercise and a reduced risk of prostate cancer in white men held even after the researchers took into account factors that could affect cancer risk, such as age, body mass index (BMI) and a family history of prostate cancer.
The findings agree with some previous research that found regular exercise lowered the risk of prostate cancer compared with no exercise.
However, the new study only found an association, not a cause-effect link. So it's possible other factors could explain the association, such as diet or how often the men visited the doctor.
While the role exercise may play in prostate cancer risk requires further investigation, an increase in healthy eating habits and exercise in the United States would likely reduce the overall cancer burden, Clinton said.