A study shows that carriers of nicotine-related genetic variants smoked fewer cigarettes

This is a promising finding, as the study describes a rare variant that reduces the function of the CHRNB3 gene and is associated with health benefits—specifically, a reduction in the amount of tobacco smoked daily. In theory, pharmacological inactivation of the gene could therefore produce a similar benefit. However, the authors did not investigate whether this same variant might be linked to other adverse health effects, which would be comparable to potential side effects of a drug designed to inactivate the gene.

Another noteworthy aspect of the study is that it highlights the importance of investigating populations from diverse geographical backgrounds rather than focusing solely on those of European ancestry. The discovery was based on sequencing data from an Indigenous Mexican population. Although the vast majority of genetic variants are shared across human populations, rare variants are more likely to be population-specific, as is the case here. This particular variant is not found in populations of European origin.

The research also showed that the variant has a much greater impact on reducing tobacco consumption in men than in women, underscoring the relevance of social factors—in this instance, those linked to gender roles. As such, it remains unclear to what extent the findings can be generalised to other populations. Although the researchers identified another rare variant that inactivates the same gene and is associated with a similar reduction in tobacco use in a Japanese population, no sex-specific data were available in that case.

In summary, the findings are promising and point to a potential new pharmacological mechanism for tackling smoking. Nevertheless, further evidence is required, particularly given that the authors declare conflicts of interest, as many are shareholders or employees of a pharmaceutical company and hold a patent related to this gene.

The article appears highly interesting. Its publication in Nature Communications, a high-impact journal, clearly attests to the rigour of the research. As for whether a therapy for nicotine addiction based on blocking the β3 subunit of the CHRNB3 gene is viable, speaking personally, I believe it is always advisable in medicine to interpret results with caution and to avoid raising false therapeutic expectations—for instance, regarding the short-term feasibility of a treatment for nicotine addiction such as the one proposed.

Similar studies involving other genes that also play a role in nicotine addiction have not ultimately led to therapeutic applications. The range of brain receptors and neurotransmitters (and the genes encoding them) involved in nicotine addiction is broad and complex, and to a large extent still not fully understood.