Smoking may increase the risk of developing dementia, according to Korean research published in the Annals of Clinical and Translational Neurology. Quitting reduces the risk.

Researchers followed 46,140 men aged 60 years and older for a mean of 7.11 years. Compared to people who continued to smoke, long-term quitters (at least four years) and those who had never smoked were 14 and 19 per cent respectively less likely to develop dementia. Never smokers were 18 per cent less likely to develop Alzheimer’s disease than people who continued to smoke. Longterm quitters and those who had never smoked were 32 and 29 per cent less likely to develop vascular dementia.

The authors point out that the study has certain limitations. For instance, the follow-up may have been too short to fully determine whether quitting smoking influenced the risk of developing Alzheimer’s disease, while the study did not include other neurodegenerative diseases, such as Parkinson’s disease and amyotrophic lateral sclerosis.

Nevertheless, the authors conclude that “smokers should be encouraged to quit in order to reduce the risk of developing dementia, especially in the elderly population who are already at risk”.