A study reveals genetic variants that predispose to the consumption of alcohol or tobacco

The number of smokers has dropped drastically in recent years;

information about the harmful effects of tobacco, the increase in prices and the prohibition of advertisements and smoking in public places have had an effect and continue to have an effect.

From 2014 to now, in Spain, for example, there are 11.7% fewer smokers.

Cultural factors make a difference in the number of people who have this habit, but to continue improving the prevention of health problems caused by smoking or alcoholism, it is also interesting to understand the biological factors that make some people more prone to these addictions.

This week, in a paper published in the journal

, an international group of scientists has found 4,000 genetic associations that have a certain influence on the consumption of alcohol or tobacco, taking into account factors such as the age at which these substances begin to be consumed or how much they are taken.

In this study, which includes more than three million people (80% of European descent and 20% of the rest of the world), it is observed that, despite living in a similar environment, people with a greater genetic predisposition smoke more .

"Individuals in the top 10% of genetic predisposition to tobacco use smoke on average twice as many cigarettes per day as those in the bottom 10% (14 cigarettes vs. 7)," says Javier Costas, lead researcher in the Psychiatric Genetics group. of the Santiago de Compostela Health Research Institute (IDIS), in statements to the Science Media Center.

This ability to predict smoking or alcohol use is much higher among people of European ancestry than with the rest, due to the smaller number of samples available.

However, the authors emphasize that although minor,

The analysis, which is a first step to begin to identify biological risk factors for smoking or alcoholism, understand them and use them in health policies, observes, for example, that some variants that help predict the number of cigarettes smoked per day by a person are related to those that increase the risk of relapse among cocaine users or aggressiveness.

In a similar 2019 study, teams of scientists, including some signatories to the one now being published, looked for a correlation between alcoholism, which is around 49% heritable, and other mental disorders.

In this genetic study, they observed correlations between alcoholism and attention deficit, schizophrenia or depression.

One of the data that caught the attention of the authors was that the overlap between the genes associated with alcohol addiction and those associated with moderate consumption was not great.

According to Costas, the main limitation of the work published by

this Wednesday and other similar ones "is the definition of the characters under study, generally declared by the participants themselves and very little specific."

For example, two very different patterns of alcohol consumption, such as regular drinking with meals or weekly bottled drinking, can result in the same number of alcoholic beverages consumed per week.

“It is also known that people with health problems tend to underreport alcohol and tobacco use,” she explains.

And it is clear that public policies also play a role.

In 2014, it was 50 years since the United States Surgeon General, the highest health authority in that country, published a report on the effects of tobacco on health.

The percentage of American smokers fell in that half century from 42% to 18%, a cultural change that helped prevent, according to an estimate published in

magazine , eight million premature deaths.

In another work that appeared in the same issue of the magazine, it was calculated that between 1980 and 2014, the percentage of smokers worldwide had fallen from 41.2% to 31.1% among men and from 10.6% to 6.2% among women

For the future, the authors state the importance of expanding the samples that are studied and increasing the number of people of non-European descent to better refine the weight of genes and the environment in the consumption of alcohol and tobacco.

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