Smoking is associated with a significant loss of brain tissue and therefore causes the brain to shrink. This could explain why people who smoke generally have an increased risk of age-related decline in cognitive function and why they are at increased risk of Alzheimer’s disease.
In a new study involving experts from the Washington University School of Medicine, the connection between daily smoking and brain volume was examined. In addition, an analysis of the connection between the genetic risk score for daily smoking and brain volume was carried out. The results have been published in the English-language journal “Biological Psychiatry”.
Effects on brain volume examined
For the study, a data set from the UK Biobank was evaluated, which included a total of 32,094 participants of European descent. The brain volume was determined using imaging techniques.
It was shown that there is a connection between smoking in the past and brain volume. The general rule was that the more the participants smoked daily, the greater the reduction in brain volume, the team explains
It has long been known among experts that there is a connection between smoking and smaller brain volume. According to the researchers, it was previously unclear what the trigger was. Another factor could play an important role here: genetics.
The size of the brain and smoking behavior are hereditary, with around half of the risk of people smoking being due to their existing genes, the experts report. A so-called mediation analysis of the connections showed that the genetic predisposition leads to smoking, which in turn contributes to a smaller brain volume.
Premature aging of the brain
When people stop smoking, this prevents the loss of further brain mass, but the brain will not return to its original size, the researchers add. Smoking is linked to premature aging of the brain.
“You can’t undo the damage that’s already been done, but you can avoid doing more damage. Smoking is a modifiable risk factor,” adds study author Yoonhoo Chang in a press release.
“There is one thing you can change to prevent your brain from aging and putting yourself at increased risk of dementia, and that is to stop smoking,” emphasizes the doctor.
Smoking causes significant damage to the brain
Until now, the effects of smoking on the brain have received less attention because research has focused more on its effects on the lungs and heart, said study author Dr. Laura J. Bierut. However, the new study makes it clear that smoking also damages the brain. (as)