Physical Activity Decreases Risk of Developing Cancer in Japanese Men and Women
Reported August 15, 2008Researchers from Japan have reported that increased daily physical activity decreases the risk of cancer development in a relatively lean population. The details of this study appeared in the August 15, 2008 issue of the American Journal of Epidemiology.1
Increased physical activity has been associated with a decreased risk of breast cancer. However, the impact of exercise on other cancers has not been well studied. Studies of exercise can also be confounded by dietary habits and obesity which may also have an impact on cancer risk. At least one study has shown that exercise does not compensate for the increased cancer risk in obese women. The current study is of major interest since it was carried out in a predominantly lean population in Japan.
Researchers affiliated with the Japan Public Health-Center-based Prospective Study evaluated cancer risks in almost 80,000 persons aged 45-74 years. They reported that the risk reduction for developing all types of cancer were reduced by 13% in men and 16% in women with the highest level of physical activity compared to the lowest level of activity. These authors also stated that the effect was greater in women than men especially in the elderly. The main sites affected in men were colon, liver and pancreas and the main site affected in women was the stomach.