Tobacco and alcohol use are major risk factors for a variety of diseases and disorders.
There is strong evidence from existing studies that genetics plays a role in the use of tobacco and alcohol.
However, previous genome-wide association studies of large numbers of individuals have focused on individuals of European ancestry, and scientists know little about the genetic role of these behaviors in other populations.
Recently, a multi-descent genome-wide association study (GWAS) involving more than 3 million people identified nearly 4,000 genetic factors associated with smoking and drinking behaviors.
The results of the study have been published in the journal Nature.
The researchers analyzed GWAS data from 60 cohorts containing nearly 3.4 million people, representing four groups with different ancestors (African, American, East Asian, and European).
More than 20% of the cohorts were from populations with non-European ancestors.
From these, the researchers identified nearly 4,000 genetic variants associated with smoking or drinking behavior (such as the age at which individuals started smoking or the number of alcoholic beverages consumed per week).
The scientists found that most of these variants showed consistent effects across ancestry populations.
However, polygenic scores, a measure of genetic association based on the combined effects of multiple genetic variants, trained with data from individuals of European ancestry, showed reduced performance in predicting other populations.
This finding suggests that such prediction methods remain difficult to migrate across populations of different ancestry.
This study improves our understanding of the genetic factors associated with smoking and drinking behaviors and highlights the importance of increasing sample size and ancestral diversity.