Nature. The researchers found more than 3,500 genetic variations that potentially affect smoking and drinking behaviors in a genome-wide association study. This study included almost 3.4 million people with African, American, East Asian, and European ancestry. Of the 3.4 million people, 21% had non-European ancestry.
The researchers identified 3,823 genetic variants that were associated with smoking or drinking behaviors in individuals. Of the more than 3,500 variants, thirty-nine were linked to the age at which individuals started smoking, 243 were linked to the number of cigarettes smoked per day, and 849 were linked to the number of alcoholic drinks consumed per week.
In my opinion, although these behaviors may be genetically linked, smoking and drinking are still environmentally influenced. The genetics part could be more so to do with how one reacts when they do smoke and drink. The genetic links could also affect how easily the risks of other health conditions arising from drinking and smoking, as smokers are more likely to develop heart disease, strokes, and lung cancer. Likewise, drinking can lead to the development of multiple chronic diseases, such as high blood pressure, heart disease, cancer, and multiple mental health issues and memory problems.