A recent study examining potential links between sustained cessation from cigarette smoking and risk for developing dementia, found compelling evidence that nonsmokers and long-time former smokers have a reduced risk for dementia compared to recent quitters or current smokers, relative to the length of time they have not smoked.
The current study included over 46,000 participants, who were all men over the age of 60 in a National Health Screening Cohort of the Korean Health Insurance System. After controlling for various factors including patient age, income, physical activity, BMI, and more, participants were broken down into the following groups: continuous smokers, short-term quitters (those who had quit smoking in the past four years or less), long-term quitters (those who had quit over four years ago), and lifetime non-smokers.
The findings showed a clear reduction in the risk of developing Alzheimer’s Disease (AD) or vascular dementia (VD) relative to cigarette smoking status: those who had never smoked had the greatest reduced risk for dementia compared to continuous smokers (18% reduced risk for AD and 29% for VD), long-term quitters had the next greatest reduction in risk for dementia (15% for AD and 32% for VD), and short-term quitters still had lower risk compared to continuous smokers (8% lower for AD and 19% lower for VD).
Although this study has some limitations and leaves plenty of room for future investigation, it provides strong evidence to bolster those in the healthcare field who are advocating for their patients to quit smoking as soon as possible, regardless of how long they have been smoking. The longer an individual has lived without the damaging effects of cigarette smoking, the better.
Choi, D., Choi, S., Min Park, S. (2018). Effects of smoking cessation on the risk of dementia: a longitudinal study. Annals of Clinical and Translational Neurology. DOI: 10.1002/acn3.633.