March 05, 2012
Marc Gordon, MD
Everyone knows smoking is dumb. Now it looks like it makes you dumb, too: A recent study in the Archives of General Psychiatry suggests that male smokers of a certain age experience faster loss of brain power.
Researchers found that, compared to men who never smoked, middle-aged men smokers are likely to experience more rapid decline in certain mental abilities over a period of 10 years. Recent ex-smokers also showed greater cognitive loss, although researchers observed no lasting effect in men who had quit more than 10 years earlier. The study also suggests that the negative association between smoking and cognition, especially at advanced ages, may actually be underestimated because of smokers' higher risk of death and drop-out.
Yet how smoking results in decreased mental abilities remains unclear. In this trial, cardiovascular disease, hypertension, elevated cholesterol or impaired lung function did not account for the effect. While the study didn't show an association between smoking and cognitive decline in women, there was a smaller proportion of women (about 30 percent) in the trial group and a higher percentage of women had never smoked. The average pack-years of smoking and number of cigarettes smoked were higher in men than in women and heavy alcohol consumption was considerably higher in men (38.7 percent) as compared to women (23.3 percent) smokers.
This study presents not only more evidence that smoking is bad for you, but it also shows that mid-life smoking is a modifiable risk factor which, left unchecked, will rob your brain of about 10 years.