Researchers with the University of Southern California looked at more than 17,000 brain scans and found that people who are daily drinkers and smokers had significantly higher relative brain age than people who aren't.
Every gram of alcohol consumed each day was associated with roughly seven-and-half days of brain aging, researchers found.
"Besides smoking and alcohol consumption, various environmental factors may be associated with brain age," researchers noted. "For example, physical exercise and meditation had been reported to be associated with lower brain aging level."
The study's authors said that their results suggest that structural brain aging is linked to both environmental and genetic factors.
The research appears in the journal Scientific Reports.