Smoking Thins the Brain, and That’s Not a Good Thing

By Reid Schram, Epoch Times
February 11, 2015 7:27 pm Last Updated: February 24, 2015 2:46 pm

Smoking tobacco is the leading cause of preventable death, according to the U.S. Centers for Disease Control. Now there’s evidence of another negative side affect: thinning of the very important cortex regions of the brain.

This thinning was recently identified by an international team of researchers from the Montreal Neurological Institute at McGill University and the University of Edinburgh.

Cortex thinning is a part of aging, and smoking appears to accelerate that process. This thinning is believed to contribute to elderly cognitive decline.

“We found that current and ex-smokers had, at age 73, many areas of thinner brain cortex than those that never smoked. Subjects who stopped smoking seem to partially recover their cortical thickness for each year without smoking,” said Dr. Sherif Karama, assistant professor of psychiatry at McGill University, in a press release.

What’s surprising is the slow recovery process for former heavy smokers. Even after 25 years of not smoking, their brains were still thinner than non-smokers.

Figure 2 lower res
Cortical thickness contrasts between three smoking categories: A: Never smoked versus current smokers – regions in yellow/orange are where those that never smoked have a thicker cortex than current smokers B: Ex-smokers versus current smokers – regions in yellow/orange are where ex-smokers have a thicker cortex than current smokers C: Never smoked versus ex-smokers – regions in orange are where those that never smoked have a thicker cortex than current smokers D: Mean cortical thickness across the whole brain for those that never smoked, ex-smokers, and current smokers (McGill University)

The study looked at 244 male and 260 female subjects who had been examined as children in 1947 as part of the Scottish Mental Survey. The average age of the subjects was 73 and included smokers, non-smokers, and ex-smokers. Their brains were analyzed with a Magnetic Imaging Resonance (MRI) scan.

“Smokers should be informed that cigarettes could hasten the thinning of the brain’s cortex, which could lead to cognitive deterioration. Cortical thinning seems to persist for many years after someone stops smoking,” says Dr. Karama.