A number of previous studies report that physical activity exerts a protective role in a number of cancers. Mathieu Boniol, from the International Prevention Research Institute (France), and colleagues completed a meta-analysis of 37 studies, involving a total of over four million women subjects, that assessed the relationship between physical exercise and breast cancer risk. The researchers found that engaging in sports for more than an hour day reduces the risk of contracting breast cancer, and this applies to women of any age and any weight, and also unaffected by geographical location. Compared with the least active women, those with the highest level of physical activity reduced their risk of breast cancer by 12%. The lead author urges that: “Adding breast cancer, including its aggressive types, to the list of diseases that can be prevented by physical activity should encourage the development of cities that foster sport by becoming bike and walk-friendly, the creation of new sports facilities, and the promotion of exercise through education campaign. This is a low cost, simple strategy to reduce the risk of a disease that currently has a very high cost, both to healthcare systems and to patients and their families. It is good news both for individuals and for policy makers.”
