Smoking is linked to accelerating age-related thinning of the the brain's outer layer, the cortex, but this damage may be reversible after quitting, according to a study published in Molecular Psychiatry.
However, the recovery may not be full and the process can take up to 25 years.
Previous studies have linked cigarette smoking with cognitive decline, dementia, and brain degeneration. However, no studies had explored whether this damage could be reversed.
This new study included 504 Scottish people aged 70 to 79 years who had been participants in the Scottish Mental Survey as school children in 1947, which tested their cognitive function. Each participant underwent MRI scans again in 2007. The study included 36 current smokers, 223 ex-smokers, and 245 people who had never smoked.
On average, the current smokers had thinner cortexes than those who had never smoked.
The ex-smokers had smoked an average of one pack a day over a span of 30 years. The researchers found that it took approximately 25 years after they quit smoking for their cortical thickness to be similar to that of non-smokers. However, among ex-smokers who smoked more heavily, thinner cortexes were still seen even 25 years after quitting.
While the researchers are unsure of exactly how or why the cortex rebuilds after quitting smoking, they hope that their research will provide encouragement for current smokers to quit.
Health Implications of Cigarette Smoking
More deaths are caused each year by tobacco use than by all deaths from HIV, illegal drug use, alcohol use, motor vehicle injuries, suicides and murders combined, according to the CDC.The good news: Nearly 70% of smokers want to quit,…
Damage to the brain’s outer layer caused by smoking may be reversible after quitting, but it could take years, a study said.
Brain scans of 500 Scottish septuagenarians confirmed a link between smoking and an acceleration of age-related thinning of the cortex—the outer layer of grey matter, researchers reported.
But they also pointed, for the first time, to potential for recovery after quitting.
The cortex of ex-smokers in the group “seems to have partially recovered for each year without smoking,” the multinational research team wrote in the journal Molecular Psychiatry.