The study gathered health data and analysed MRI scans of 244 males and 260 females with an average age of 73.
Scientists found that smoking appeared to accelerate the thinning of the outer layer of the brain (cortex), seen in normal brain ageing. This can affect important thinking skills such as planning, decision-making and problem-solving. Participants in the study who had given up smoking appeared to have a thicker cortex than more recent quitters. The study suggests that avoiding smoking helps maintain the normal thickness of the cortex, protecting against age-related cognitive decline.
Dr Doug Brown, Director of Research at Alzheimer’s Society said: “It’s common knowledge that smoking damages our heart and lung health, but many people are still unaware that smoking can also increase their risk of dementia.
“This study builds on earlier research that suggests smoking can reduce the volume of some brain regions and, therefore, age the brain faster. There is significant evidence to show smoking puts people at a greater risk of developing dementia than those who have never smoked, but this risk can be meaningfully reduced by quitting the habit. Importantly, this study backs this up, providing some evidence that brain volume can recover after smoking cessation.”