Experts say that nearly 4,000 genetic variations influence our smoking and drinking habits. 

With the end-of-year party season looming, many might be surprised to find out that smoking and drinking habits are heavily influenced by genes.

Australian scientists have helped identify nearly 4,000 genetic variants linked to a number of characteristics including the number of alcoholic drinks a person drinks each week and the age at which people start smoking. 

The genetic associations were identified in a multi-ancestry genome-wide association study (GWAS) involving almost 3.4 million individuals.

The GWAS data was from 60 cohorts containing almost millions of individuals representing 4 ancestry groups (African, American, East Asian and European ancestries). 

The researchers found that the majority of these variants showed consistent effects across different ancestries. 

The researchers say their findings improve the understanding of genetic factors associated with smoking and drinking behaviours.

The full report is accessible here.