Cigarette smoking might be a risk factor for dementia.

​The purpose of this meta-analysis was to review previously published studies that examined the relationship between cigarette smoking and the risk of dementia. A total of 37 studies were included in this meta-analysis. 

Researchers noted that the probability of experiencing dementia was higher in current smokers than in former and never smokers. Regular smoking of 20 sticks of cigarettes per day was found to increase the odds of dementia by 34% in this study. However, cessation of smoking significantly decreased the risk of dementia. This meta-analysis provides strong evidence of an excess risk of dementia among current smokers.