According to an American study, smoking probably causes brain shrinkage. Quitting cigarettes could therefore limit your risk of Alzheimer’s. Yet another new benefit to smoking cessation!
“Until recently, scientists have neglected the effects of smoking on the brain, in part because we focused on all the terrible effects of smoking on the lungs and heart“, says Professor Laura J Bierut, professor of psychiatry. “But as we began to look more closely at the brain, it became clear that smoking is also very bad for the brain“.
The real effects of smoking on the brain
Scientists have long suspected that smoking could lead to a reduction in brain volume, but without really clarifying the phenomenon in question. The team of Professor Laura J Bierut from the University of Washington School of Medicine considered a third factor: genetics. Brain size and smoking behavior are hereditary. About half of a person’s risk of smoking can be attributed to their genes.
To unravel the relationship between genes, the brain and behavior, researchers analyzed data drawn from the UK Biobank, a biomedical database that contains genetic, health and behavioral information on half a million people. Among them, more than 40,000 benefited from brain imaging, capable of determining the volume of the brain. In total, the team analyzed anonymized data on brain volume, smoking history and genetic risk of smoking in 32,094 people.
A possible risk factor for dementia
The results show links between different factors: smoking history and brain volume; smoking-related genetic risk and smoking history; and genetic risk linked to smoking and brain volume. Additionally, the more packs per day a person smoked, the more their brain volume was reduced. When considering all three factors together, the researchers found that the association between smoking genetic risk and brain volume disappeared, while the link between each of them and smoking-related behaviors remained.
In summary : a genetic predisposition leads to smoking, which causes a decrease in brain volume.
And unfortunately, this decrease seems irreversible. “You can’t undo the damage you’ve already done, but you can avoid causing more“said co-author Yoonhoo Chang. The findings help explain how smoking is linked to Alzheimer’s disease and dementia.”Smoking is a modifiable risk factor. To limit the aging of your brain and an increased risk of dementia, you can act, you must stop smoking!” concludes Dr. Chang.