Regular alcohol and tobacco use makes the brain age a little faster. This is the conclusion reached by scientists who used artificial intelligence (AI) to link images of the brain with people’s smoking and drinking habits.
The team led by arthur toga of the university of southern california in los angeles (california, u.S.A.) presents its findings in the journal "scientific reports.
"It is known that certain lifestyle habits are associated with accelerated degradation in certain brain regions," the researchers write. However, how smoking and drinking, as well as genetic factors, affect the aging of structures throughout the brain is largely unclear, they said. That’s why toga and colleagues used data from the UK biobank, which links scans of the entire brain with the subjects’ lifestyles.
Of the 17.308 magnetic resonance imaging images, the scientists used 30 percent to train a statistical model using AI. They taught the model to determine the relative brain age of an individual subject based on MRI images. This is the brain age of a person compared to the average brain age of his or her peers. It therefore indicates whether the brain is older or younger than its actual age. They then used the trained model to determine the relative brain age of the remaining 70 percent of the subjects.
In brain performance tests, those with a lower brain age had performed better than those with a higher brain age.
Toga’s team found statistically significant, albeit small, influences of smoking and alcohol consumption on relative brain age. Every year that a person smokes a pack of cigarettes every day or almost every day ages the brain by an additional 0.03 years, or about 11 days. Every extra gram of alcohol a person consumes per day increases relative brain age by 0.02 years. This corresponds to about 7 days. Researchers found no evidence that the effects of alcohol consumption on the brain influence the effects of tobacco consumption or vice versa.
The scientists also studied the effects of more than 500.000 point mutations on brain age. These are changes in individual base pairs in the genetic material. Only one gene was found to have a statistically significant association. The gene – called MAPT – is responsible for the production of tau protein, which is also linked to the development of dementia and parkinson’s disease.
Toga and his colleagues admit that the connections are not particularly rough. However, all test persons are people with normal brain functions. When people with impaired brain functions were included in a study, the results could be more significant.