Physical activity and risk of cancer in middle-aged men

A prospective study was carried out to examine the relationship between phy sical activity and incidence of cancers in 7588 men aged 40-59 years with f ull data on physical activity and without cancer at screening. Physical! ac tivity at screening was classified as none/occasional, light, moderate, mod erately-vigorous or vigorous. Cancer incidence data were obtained from deat h certificates, the national Cancer Registration Scheme and self-reporting on follow-up questionnaires of doctor-diagnosed cancer. Cancer (excluding s kin cancers) developed in 969 men during mean follow-up of 18.8 years. Afte r adjustment for age, smoking, body mass index, alcohol intake and social c lass, the risk of total cancers was significantly reduced only in men repor ting moderately-vigorous or vigorous activity; no benefit seen at lesser le vels. Sporting activity was essential to achieve significant benefit and wa s associated with a significant dose-response reduction in risk of prostate cancer and upper digestive and stomach cancer. Sporting (vigorous) activit y was associated with a significant increase in bladder cancer. No associat ion was seen with colo-rectal cancer. Non-sporting recreational activity sh owed no association with cancer. Physical activity in middle-aged men is as sociated with reduced risk of total cancers, prostate cancer, upper digesti ve and stomach cancer. Moderately-vigorous or vigorous levels involving spo rting activities are required to achieve such benefit. (C) 2001 Cancer Rese arch Campaign http://www.bjcancer.com.