Led by dozens of authors, new study assesses information gathered from nearly 3.4 million people, not all of European descent, and identifies thousands of genetic variants linked to tobacco and alcohol use .
An international group of researchers conducted a study and identified more than 3,500 genetic variations that may affect smoking and drinking habits.
The study involved nearly 3.4 million people of diverse backgrounds, including African, American, East Asian and European ancestry.
The results were published in Nature December 7. They point out that increasing sample size and ethnic diversity improves the power of genome-wide association studies (GWAs) such as these, showing that various traits are linked to genes, combinations of genes or mutations.
The scientific community already considers smoking and alcohol as risk factors for several physical and mental illnesses, including cardiovascular disease and psychiatric disorders.
Despite the fact that smoking and drinking are both affected by environmental and social factors, evidence points to genetics as another underlying influence of tobacco and alcohol use.
“We are at a stage where genetic discoveries are being translated into clinical [applications]says study co-author Dajiang Liu, a statistical geneticist at Penn State College of Medicine in Hershey, Pennsylvania.
“If we can predict a person’s risk of developing nicotine or alcohol addiction using this information, we can intervene early and potentially prevent many deaths.”
A diverse set of topics
Scientists compare the genetic sequences of large numbers of people using GWAs to find genetic links to diseases or behaviors. However, in the past, these studies have relied heavily on European individuals.
This time around, Liu and his colleagues used a model that used genomic data from 3,383,199 people (almost 3.4 million), and 21% of that population had non-European ancestry.
The researchers identified 3,823 genetic variants associated with smoking or alcohol consumption, of which 39 were linked to the age at which people started smoking, 243 to the number of cigarettes smoked per day and 849 to the number of alcoholic drinks. consumed. per week.
At least 721 related variants out of the total were detected by multi-ancestry GWAs alone, as opposed to a naïve ancestry model that the researchers used for comparison. This means that large and diverse population samples improve and increase the power of these studies.
According to the researchers, the majority of genetic associations for drinking and smoking have similar effects across different ancestors.
“We also find similar heritability estimates [for the traits] across ancestors…suggesting that generally, the genetic architecture of these behaviors is similar across ancestors,” says Gretchen Saunders, a psychologist at the University of Minnesota, Minneapolis, and co-author of the paper.
On the other hand, the researchers also demonstrated that polygenic risk scores specific to the European ancestry group did not correctly predict smoking and drinking behaviors in other ancestry groups.
“Even with these large sample sizes, they just don’t transfer from population to population,” Saunders says.
Environmental effects on smoking and alcohol consumption
One of the authors, Ananyo Choudhury, a geneticist at the University of the Witwatersrand in Johannesburg, South Africa, explains the similarity between the ancestors in part with the vast majority of non-European cohorts living in the United States and having environmental influences similar, such as public health policies and the availability of alcohol and nicotine products.
“Epigenetic and environmental factors are really important in turning genes on and off. So maybe it is because of this reason, there are not many [significant] differences,” adds Sehime Temel, who studies medical genetics at Bursa Uludag University in Turkey.
The analysis did not include people from the Middle Eastern and Indian populations, where smoking is often prevalent.
“Tobacco use is very common [in the Middle East]. There is a huge consumption of hookah,” says Mahmut Ergoren, a medical biologist at the Near East University in Lefkosa, Turkish Republic of Northern Cyprus.
Ergoren thinks adding these populations would increase the precision of the study and help identify more genetic associations.
The researchers admit that even larger than many, their sample still doesn’t yield the most diverse results possible in terms of genetic ancestry or geography.
“Although this is the largest and most diverse study of smoking and alcohol use phenotypes to date, it did not cover all populations,” Liu says. “In future phases of the study, we will welcome collaborations from other researchers who have access to additional data sets to further expand our studies.”
Source: TRTWorld and agencies