The association of a combined healthy lifestyle with the risk of cancer among older adults: a prospective large population-based cohort study

Maintaining healthy habits may curb cancer incidence among Western populations. However, evidence from Chinese seniors remains limited, despite the country facing a rapidly aging population and the well-established fact that older adults are at a disproportionately high risk for cancer. Leveraging a large-scale prospective cohort of Chinese seniors, we examined how a composite lifestyle score correlates with their cancer risk. A total of 109 018 seniors whose first cancer diagnosis was recorded in Kunshan constituted the prospective cohort under investigation. A healthy lifestyle score was constructed based on five factors assessed at baseline: smoking, alcohol consumption, dietary habits, body mass index (BMI), and physical activity. Cox proportional hazards regression was employed to compute hazard ratios (HR) and 95% confidence intervals (CI), thereby assessing how the combined lifestyle metric influenced the risk of developing cancer. Among 109,018 older adults enrolled between 2017 and 2025, throughout a mean follow-up period of 7.34 years, 2,115 incident cancers were documented. A significant inverse dose-response relationship was observed between the healthy lifestyle score and cancer risk ( p for trend < 0.001). With the four additional lifestyle factors controlled for, diet and exercise were among the lifestyle factors most strongly associated with cancer risk. Adjusted HR for cancer risk with lifestyle score of 5, versus 0–2, were 0.37 (95% CI: 0.29–0.46) in the overall population, 0.32 (95%CI, 0.22–0.46) in men,0.39 (95%CI 0.29–0.52) in women, 0.45 (95%CI, 0.31–0.65) in those aged 60–70 years, and 0.32 (95%CI, 0.24–0.42) in those aged > 70 years. Notably, this protective association was substantially stronger among adults aged over 70 years compared to those aged 60–70 years. Embracing favorable lifestyle habits was associated with lower cancer susceptibility. This study emphasizes that heightened awareness is required among elderly Chinese populations regarding the potential benefits of healthy habits in cancer prevention.