Recommended levels of physical activity reduce individuals' risks of seven different cancers
The results of a new pooled analysis, involving data on over 750,000 individuals, suggest that recommended amounts of physical activity are linked with lower risks of seven different types of cancers.
The association between physical activity and reduced cancer risk is well established, however, the nature, or ‘shape’, of the relationship between the recommended amounts of physical activity and individuals' risks of specific cancers have been less well investigated. In a new pooled analysis, researchers from the National Cancer Institute (MD, USA), American Cancer Society (GA, USA), and Harvard T.H. Chan School of Public Health (MA, USA) have reviewed data on more than 750,000 adults and determined that recommended amounts of physical activity are linked with lower risks of seven different types of cancers, often in a dose-dependent manner.
Updated physical activity guidelines recommend that adults should aim to perform 2.5–5 hours of moderate–intense activity – activity that gets one moving enough to burn off between three and six times the amount of energy that one would burn sitting quietly – each week; this is equivalent to 1.25–2.5 hours of vigorous physical activity per week.
In this study, researchers pooled data on 755,459 adults, who self-reported their levels of leisure-time physical activity, from nine prospective studies, each with recorded cancer incidence follow ups for 15 different cancer forms over 10.1 years.
Researchers observed a statistically significant association between engaging in recommended levels of activity each week and individuals’ lower risks of developing seven of the 15 different cancer types studied. This association was often dose dependent; cancer risk decreased more with each incremental increase in participants’ levels of weekly physical activity.
Key findings include physical activity being linked with at least an 8% lower risk of colon cancer in men and at least a 6% risk reduction of breast cancer for women.
The study authors concluded: “These findings provide direct quantitative support for the levels of activity recommended for cancer prevention and provide actionable evidence for ongoing and future cancer prevention efforts.”
Commenting on the research, Alpa Patel (American Cancer Society), stated: “Physical activity guidelines have largely been based on their impact on chronic diseases like cardiovascular disease and diabetes. These data provide strong support that these recommended levels are important to cancer prevention, as well.”
Matthews CE, Moore SC, Arem H et al. Amount and intensity of leisure-time physical activity and lower cancer risk. J. Clin. Oncol. doi:10.1200/JCO.19.02407 (2019) (Epub ahead of print);