Physical activity and cancer risk:a dose-response analysis for the Global Burden of Disease Study 2019

Objective Adopting a healthy lifestyle,including regular physical activity,is widely believed to decrease cancer risk.This study aimed to quantitatively establish the dose-response relationships between total physical activity and the risk of breast,colon,lung,gastric,and liver cancers.Methods A systematic review and dose-response analysis were conducted using PubMed and Embase from January 1,1980 to March 20,2023.Prospective cohort studies that examined the association between physical activity and the risks of any of the 5 outcomes were included.The search was confined to publications in the English language with a specific focus on human studies.Physical activity is standardized by using the data from US National Health and Nutrition Examination Surveys(NHANES)and the Global Burden of Disease 2019 database.Results A total of 98 studies,involving a combined population of 16,418,361 individuals,were included in the analysis.Among the included studies,57 focused on breast cancer,17 on lung cancer,23 on colon cancer,5 on gastric cancer,and 7 on liver cancer.Overall,elevated levels of physical activity exhibited an inverse correlation with the risk of cancer.The dose-response curve for lung cancer exhibited a non-linear pattern,with the greatest benefit risk reduction observed at 13,200 MET-minutes/week of physical activity,resulting in a 14.7%reduction in risk(relative risk 0.853,uncertainty interval 0.798 to 0.912)compared to the inactive population.In contrast,the dose-response curves for colon,gastric,breast,and liver cancers showed linear associations,indicating that heightened levels of total physical activity were consistently associated with reduced cancer risks.However,the increase in physical activity yielded a smaller risk reduction for colon and gastric cancers compared to breast and liver cancers.Compared to individuals with insufficient activity(total activity level<600 MET-minutes/week),individuals with high levels of activity(≥8,000 MET-minutes/week)experienced a 10.3%(0.897,0.860 to 0.934)risk reduction for breast cancer;5.9%(0.941,0.884 to 1.001)for lung cancer;7.1%(0.929,0.909 to 0.949)for colon cancer;5.1%(0.949,0.908 to 0.992)for gastric cancer;17.1%(0.829,0.760 to 0.903)for liver cancer.Conclusions This study demonstrated a significant inverse relationship between total physical activity and the risk of breast,gastric,liver,colon,and lung cancers.