A Genome-wide study on the genetic and causal effects of smoking in neurodegeneration

Publication date: Jul 05, 2025

Some research even suggests a dose-dependent negative association between smoking and PD risk, meaning that smoking may reduce the risk of developing PD [47, 48]. Moreover, high levels of smoking exposure (measured by lifetime smoking years or pack-years) have been associated with more severe neurocognitive dysfunction, and smokers have poorer functional recovery . This result suggests that the protective effect of smoking diminishes with continued smoking, as sustained oxidative stress may lead to ongoing disease progression . Although current smokers are more likely than quitters or non-smokers to exhibit cognitive decline, neither study found a significant association between smoking status and the residual reserve index. Similarly, a Chinese study reported that former smokers had better cognitive performance than never-smokers, and that years of smoking were positively correlated with cognitive function across all participants . Our results, from a genetic perspective, indicate that smoking cessation is associated with a reduced risk of developing ALS. Notably, ALS mortality is higher among female smokers, whereas no such increase is observed in males , suggesting that sex differences may be a factor in ALS risk.

Semantics

Original Article