Yet another reason to stop smoking: It may reduce your risk for dementia.

Korean researchers studied 46,140 men, 60 and older, following them for an average of eight years with periodic health examinations. Over the course of the study, 1,644 people were given a diagnosis of Alzheimer’s disease or another form of dementia.

After controlling for age, body mass index, blood pressure, physical activity and other health and behavioral characteristics, they found that the less time men smoked, the less likely they were to have dementia. Compared with continual smokers, men who had quit for up to four years had a 13 percent lower risk, those who had quit for four years or more a 14 percent lower risk, and never-smokers a 19 percent lower risk.

The study is in the Annals of Clinical and Translational Neurology.

The authors acknowledge that they had no data on education level, which is a risk factor for dementia, and that the eight-year follow-up may not have been long enough to pick up all cases of dementia, a disease that develops slowly.

“Smoking has not been well known as a risk factor for dementia,” said the lead author, Dr. Daein Choi, a researcher at the Seoul University College of Medicine. “Our findings suggest that smoking cessation, or reduced smoking, might be helpful in reducing the risk.”