Alcohol, smoking, and brain structure: common or substance specific associations

Area of Science:

• Neuroimaging
• Substance Use Research
• Brain Health

Background:

• Alcohol use and smoking are prevalent behaviors linked to adverse health outcomes, including cognitive decline.
• Understanding the specific neurobiological impacts of these substances is crucial for public health.
• Previous research suggests negative effects, but a direct comparison of their brain associations is less explored.

Purpose of the Study:

• To investigate the shared and distinct associations of alcohol use and smoking with neuroimaging-derived brain measures.
• To determine if the combined effects of alcohol and smoking on the brain are additive or interactive.
• To assess the directionality of these associations concerning brain health.

Main Methods:

• Utilized UK Biobank data from 36,309 participants with extensive neuroimaging data.
• Employed linear regression to analyze associations between brain measures and alcohol consumption (drinks/week) and smoking (pack-years).
• Calculated correlations between association z-scores for alcohol and smoking to compare their brain effects and tested for interaction effects.

Main Results:

• Moderate positive correlations found between alcohol and smoking associations across brain structure, magnetic susceptibility, and white matter microstructure measures.
• The primary impact of combined alcohol and smoking was additive for most brain measures, with a notable interaction observed only in subcortical magnetic susceptibility.
• Over 97% of significant associations for both alcohol and smoking indicated detrimental effects on brain health.

Conclusions:

• Alcohol use and smoking exhibit largely similar adverse associations with neuroimaging-derived brain measures.
• The detrimental effects of these substances on the brain are predominantly additive.
• Findings highlight the shared neurobiological pathways through which alcohol and smoking negatively impact brain health.