In a study, published in Nature Genetics, scientists have found that tobacco and alcohol use influence risk for many complex diseases and disorders. They both are genetically inheritable behaviors and are leading causes of mortality.
Moreover, these substances often are used together. Studies have found that people who smoke are more likely to drink, and those who drink are more likely to smoke.
The University of Minnesota was part of a research collaboration which conducted the first study. In this study, scientists identified the hundreds of genomic locations which were associated with addictive behaviors.
They found more than 500 genetic variants which affect the use of an addiction to alcohol and tobacco. Up till now, only a few of such variants had been known.
Researchers studied around 1.2 million people. They looked five characteristics of the participants including the age when they began smoking; the number of cigarettes per day they smoked; whether the participant has ever been a regular smoker; whether the participant ever quit smoking; and the number of alcoholic drinks the participant had per week.
Findings of the study
Concerns about the use of alcohol and tobacco are mainly significant given the negative impact of this drug combination on society. Researchers of the study discovered that;
- 566 genetic variants in 406 genomic locations linked to multiple stages of tobacco use (initiation, cessation, and heaviness) and alcohol use.
- 150 loci, or positions in the genome, showing the sign for association with two or more of the characteristics described above.
- Genetic risk for alcohol use was associated with lower disease risk.
- Increased genetic risk for smoking was linked to increased risk for a wide variety of health conditions like obesity and coronary artery disease.
According to the researchers of the study, these outcomes provide a solid starting point to assess the effects of these loci in model organisms. But further research is needed to see how these genes affect addiction and, ultimately, inform treatment development.
Health risks associated with tobacco and alcohol use
When used alone or together, alcohol and tobacco use may lead to major health risks. As well as leading to traumatic death and injury e.g., through car crashes.
Moreover, a growing body of evidence proposes that these substances might be more dangerous when used together. When combined they both dramatically increase the risk of certain cancers.
Cancers of the Mouth and Throat
Individuals who drink and smoke are at greater risk for certain types of cancer, mainly those of the mouth and throat. They cause about 80% of cancer cases of the mouth and throat in men and about 65% in women.
For those who drink and smoke, the risk of mouth and throat cancer increases intensely. In fact, the combined risk is higher than or equal to the risk related to alcohol multiplied by the risk associated with tobacco. Alcohol and tobacco co-use seems to greatly increase the risk of cancer of the esophagus.
During the past decade, the rate of liver cancer has dramatically increased in the United States. Though some studies have described that alcohol and tobacco may work synergistically to increase the risk of liver cancers. But still, more research is needed to explore this issue.
Tobacco and alcohol use both are major risk factors for various forms of cardiovascular disease. However, there is little evidence to suggest that smoking and drinking together raise the risk more than the sum of their independent effects.