The catastrophic legacy of smoking on the immune system: its effects persist for years after quitting

Age or genetics are two particularly important factors to consider when it comes to the immune system. However, they are not the only ones. Research published in the journal Nature shows not only that tobacco will have a similar effect, but also that its effects are irreversible. Even years after quitting the habit, the patient’s immune system will remain altered.

The study was conducted on a thousand volunteers aged 20 to 69 years who had not previously suffered from pathologies. Various parameters such as age, gender, body mass index (BMI) and finally tobacco use habits and others were established. By taking blood samples, they examined the immune system’s response to various factors, allowing them to link smoking and defenses.

The authors of this study, researchers from the Pasteur Institute in Paris, tested how smoking affects different types of protection. On the one hand, there are nonspecific defenses – innate, with which a person is born – which return to their original state after stopping smoking; on the other hand, specific or adaptive, that is, those that a person develops throughout his life. It is these latter cells that worry experts, since they are the ones that cannot return to their original state after quitting smoking.

Almost irreparable damage

Here’s how Violaine Saint-André, an immunologist at the Pasteur Institute and one of the authors of this study, explained it: “Smoking has an impact on human immunity in both the short and long term. “The latter in adaptive immunity are observed in B cells and regulatory T cells, as well as epigenetic changes.” Additionally, it states that these effects are directly proportional to the amount of time the patient smoked as well as the amount of tobacco smoked during that time.

On the other hand, Darragh Duffy, another author of the study, notes that this would mean greater ease of contracting infections and autoimmune diseases, in addition to cancer. “However, it is well known from many other previous studies that smoking increases the risk of developing several types of cancer, but the longer it has been since you quit smoking, the lower the risk,” explains Duffy.