In fact, the World Health Organization now estimates that smoking may be responsible for up to 14 percent of all cases of Alzheimer's disease, the most common form of dementia. Fortunately, there's also evidence to suggest that kicking the habit can minimize that risk.
A 2015 analysis published in the online scientific journal PLOS ONE evaluated the results of 37 studies that compared current smokers with people who never smoked or who quit. The authors found that current smokers were 30 percent more likely to develop some form of dementia than people who never smoked.
https://www.healthandwellnessalerts.berkeley.edu/alerts/memory/smoking-and-dementia_7773-1.html?
