**:Technology**.
A recent study by scientists at the University of Washington School of Medicine in the United States has shown that smoking may cause brain atrophy. Quitting smoking prevents further atrophy of brain tissue, but it does not restore the brain to its original size. This study helps explain why smokers have cognitive decline and an increased risk of developing Alzheimer's disease. Related**Published in the latest issue of the journal Biological Psychiatry: Global Open Science.
Scientists have long known that there is an association between smoking and smaller brain volume, and that both brain volume and smoking behavior are hereditary, with about 50% of the risk of smoking attributable to their genes.
To clarify the relationship between genes, the brain and human behaviour, the research team analysed data from the UK Biobank. The database is a publicly available biomedical database containing genetic, health and behavioral information of 500,000 people. More than 40,000 of these participants underwent brain imaging, which can be used to determine brain volume. In total, the team analysed data on brain volume, smoking history, and genetic risk of smoking in 32,094 people.
The results showed that smoking history, brain volume, and genetic risk were both related. In addition, the relationship between smoking and brain volume depends on the dose, and the more a person smokes per day, the smaller their brain volume will be. The researchers determined the order between the three: genetic predisposition leads to smoking, which leads to a decrease in brain volume. Moreover, the atrophy of brain volume appears to be irreversible. By analyzing data from people who quit smoking a few years ago, researchers found that their brain volume was smaller than that of people who had never smoked.
Researchers say the decrease in brain volume coincides with an increase in aging, which is important because both aging and smoking are risk factors for dementia. Quitting smoking can stop the brain from aging further and reduce the risk of dementia.