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How do genetics influence tobacco addiction?


It is estimated that 15 million Spanish adults smoke, 34.4% of the population over 16 years of age claims to smoke. Of these, between 60 and 70% are addicted to nicotine. The act of smoking involves a triple dependence: nicotine, psychological and social. Because of all the factors that accompany this phenomenon, it is so difficult to give up this unhealthy habit for the smoker and for those around him or her.

In addition, there is evidence about the role of some genes in nicotine addiction. If a person takes a genetic test and the results indicate that there is a greater genetic predisposition to be dependent on nicotine, he or she can influence environmental factors to avoid falling into the temptation to start smoking.

Tobacco is responsible for approximately 56,000 deaths per year in Spain, 30% from cancer, 20% from cardiovascular diseases and 80% from chronic obstructive pulmonary disease (COPD). Tobacco does not only affect the lungs, but has negative consequences for all the cells that make up our body.

genetica adiccion tabaco

When tobacco smoke is inhaled, the associated tar particles transport nicotine to the lungs, from where it passes into the bloodstream and then to the brain. In this process, dopamine is released. When neurons are overexcited by nicotine, dopamine secretion is limited. In the long term, the neurons adapt their metabolism, needing more nicotine to produce the same initial effect. Thus, nicotine addiction is created because the body needs more and more nicotine.

The addictive capacity of nicotine is five times greater than that of cocaine, but it has been shown that psychological dependence is stronger than physical dependence. Habits and associations made over time have to be changed and broken in order to establish new habits.

It should be remembered that smoking significantly increases the probability of developing lung cancer. Therefore, it is important to know the genetic influence of being more dependent on nicotine with a genetic analysis. Genetics plays an important role in tobacco consumption. However, it is difficult to identify the candidate genes, which shows that there are multiple genes and that smoking should therefore be considered a polygenic disease.

Genetic tests can be used to determine a person’s susceptibility to become a smoker, as well as his or her level of difficulty in giving up smoking once he or she has started. However, the most advisable thing to do is not to start smoking and, if a person is already a smoker and wants to quit, they can go to their doctor to get the help and information they need to quit a habit that harms everyone.


Carlos Manuel Cuesta

Graduate in Biology. PhD in Biotechnology

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