The findings of a new study from investigators at the National Cancer Institute, the American Cancer Society and the Harvard T.H. Chan School of Public Health suggest that physical activity reduces the risk of seven cancers in what is largely a dose-response manner — the more exercise you do, the more your cancer risk is reduced.
It’s not news that physical activity can reduce the risk of certain cancers. However, the exact nature of this relationship, and the association between recommended levels of physical activity and cancer risk has been uncertain. “These findings provide direct support for levels of activity recommended for cancer prevention and provide actionable evidence for ongoing and future cancer prevention efforts,” the authors write, urging healthcare providers and fitness professionals to encourage people to meet physical activity goals to lower their cancer risk.
Physical activity guidelines have for the most part been based on their effect on chronic illnesses such as cardiovascular disease and diabetes, explained Alpa Patel, a co-author on the study and senior scientific director of epidemiology research at the American Cancer Society. “These data proved strong support that these recommended levels are important for cancer prevention as well.”
The more exercise you do, the more your cancer risk is reduced.
What they found was that recommended physical activity levels significantly reduced the risk of developing seven different cancers, including: colon (8 to 14 percent lower risk in men), breast (6 to 10 percent lower risk), endometrial (10 to 18 percent lower risk), kidney (11 to 17 percent lower risk), myeloma (14 to 19 percent lower risk), liver (18 to 27 percent lower risk) and non-Hodgkin’s lymphoma (11 to 18 percent lower risk in women).
The relationship between physical activity and the risk of developing cancer was linear for breast, colon and endometrial cancer: physical activity beyond the recommended levels further reduced the risk of developing these cancers. The dose-response relationship between physical activity and the risk of developing the other cancers was non-linear: exceeding the recommended levels of physical activity did not further reduce cancer risk.
More research is needed to better understand differences in the dose-response relationship between physical activity levels and the risk of certain cancers and the underlying biologic mechanisms.
The study was published in the Journal of Clinical Oncology.