Association of Relative Brain Age with Tobacco Smoking, Alcohol Consumption, and Genetic Variants
Brain age is a metric that quantifies the degree of aging of a brain based on whole-brain anatomical characteristics. While associations between individual human brain regions and environmental or genetic factors have been investigated, how brain age is associated with those factors remains unclear. The study investigated these associations using UK Biobank data.
The researchers first trained a statistical model for obtaining relative brain age (RBA), a metric describing a subject’s brain age relative to peers, based on whole-brain anatomical measurements, from training set subjects (n = 5,193). The researchers then applied this model to evaluation set subjects (n = 12,115) and tested the association of RBA with tobacco smoking, alcohol consumption, and genetic variants.
The study found that daily or almost daily consumption of tobacco and alcohol were both significantly associated with increased RBA (P < 0.001). The study also found SNPs significantly associated with RBA (p-value < 5E-8). The SNP most significantly associated with RBA is located in MAPT gene.
The results suggest that both environmental and genetic factors are associated with structural brain aging.
According to the research Inverse reports,
- Every gram of alcohol consumed per day was linked to 0.02 years of brain aging — that’s about a week of additional aging in the brain.
- Cumulatively, people who reported alcohol use every day or on most days, had about 5 months (0.4 years) of additional aging in their brains compared to people who were the same chronological age as them, but reported less frequent alcohol use.
Even though plus 0.4 [due to alcohol consumption] and plus 0.6 [due to tobacco smoking] years of relative brain age may look small and not significant, these numbers are actually important, especially since they are associated with a corresponding and significant worse cognitive function,” said Giuseppe Barisano, a post-doctoral research fellow at USC, as per, inverse.