Entertainment activities and the risk of multiple sclerosis: A Mendelian randomization analysis

Modifying environmental and lifestyle factors may have the potential to prevent and ameliorate multiple sclerosis. Further elucidating the etiology of multiple sclerosis and proposing actionable prevention measures are of significant importance, but establishing causality in epidemiological data can be challenging. This study employed a two-sample Mendelian randomization analysis to evaluate the causal effect of entertainment activity factors on the risk of multiple sclerosis. Publicly accessible summary statistics derived from genome-wide association studies were utilized to assess 14 modifiable forms of entertainment activities. The inverse variance weighted random effects method was used as the primary analytical approach to estimate causal effects. Additionally, MR-Egger, weighted median, and weighted mode methods were applied to assess robustness. Systematic sensitivity analyses and heterogeneity tests were conducted to verify the reliability of our findings. We found that spending time outdoors in the summer may prevent the development of multiple sclerosis (odds ratio = 0.995; 95% confidence interval 0.991-0.999; P = .010). In contrast, the other entertainment activities studied showed no significant causal relationship with multiple sclerosis. Our results suggest that spending time outdoors in the summer may protect against the development of multiple sclerosis, providing implications for preventive measures against the disease.