A recent study suggests that smoking and drinking habits may also be influenced by our genes, even though these behaviors are primarily controlled by many environmental and social factors. More than 3,500 genetic variants have been linked in studies to potential effects on this behavior.

Given that these behaviours can put health at danger from psychiatric and cardiovascular problems and that hereditary factors might affect these behaviours, there is now much that can be done to try to change these behaviours.

The study has concentrated chiefly on people in Europe. The scientists created a model for the study using the genetic information of 3,383,199 individuals, 21% of whom were of non-European origin.

There are currently 3,823 genetic variations known to affect drinking or smoking habits. A total of 243 genes are associated to how many cigarettes a person will smoke in a day, and 849 genetic variants are linked to how many alcoholic beverages a person will consume each week. 39 genes are linked to the age at which someone will start smoking.

Researchers found that most genetic correlations between smoking and drinking had similar consequences. They further stated that the environmental and epigenetic variables play critical role in turning the genes on and off, hence differences are less.

(Source: https://www.livemint.com/science/health/gene-determines-our-smoking-and-drinking-habits-here-s-what-study-shows-11670601360514.html)