June 7, 2011 – Three hours of brisk walking a week could reduce the risk of prostate cancer progression by more than half, according to US researchers.
They conducted a study1 in 1,455 patients with early prostate cancer who were followed for 2 to 6 years after a diagnosis was made.
The protective effect of walking was only observed in those who walked at least 3 hours per week at a sustained pace. They would have reduced their risk of progression of prostate cancer (bone metastases, recurrence of tumors, need for new treatments or death attributable to this cancer) by 57% compared to those who walked at a peaceful pace or less than 3 hours .
According to the researchers, it is the intensity of the effort that counts. Vigorous exercise would reduce inflammation and counter insulin resistance, two phenomena that contribute to cancer progression.
Although considered to be relatively moderate-intensity physical activity, vigorous walking is thought to help lower blood levels of insulin-like growth factor type I (IGF-1), which causes insulin resistance. Brisk walking is also believed to increase levels of adiponectin, a protein that increases insulin sensitivity.
These results are considered preliminary since they come from an observational study carried out on a relatively small cohort. The magnitude of the protective effect of vigorous walking, however, prompts further research and suggests that physical exercise could significantly contribute to the clinical treatment of prostate cancer, the researchers believe.
Pierre Lefrançois – PasseportSanté.net
1. Richman EL, Kenfield SA, Stampfer MJ, et al. Physical activity after diagnosis and risk of prostate cancer progression: data from the cancer of the prostate strategic urologic research endeavor. Cancer Res. 2011 Jun 1; 71 (11): 3889-95.