Smoking not only increases the predisposition to developing diseases. Tobacco alters the immune system even years after quitting. Following the path taken in the 90s by the researcher Polly Matzinger, who described the internal control and protective work of the human body by the immune system, this study was published this Wednesday in the journal “Nature‘tried to answer the question Which external environmental factors change our defenses?.
To get an answer, an international team of researchers affiliated with institutions in France, Sweden and the United States analyzed the effects of 136 environmental factors on the immune systems of 1,000 volunteers between the ages of 20 and 70 living in a born in five different decades are in good health. Blood samples from 200 people exposed to these 136 pathogens were analyzed per decade, half of whom were women and half of whom were men.
The scientists examined the quantity in particular Cytokines (a group of proteins crucial for controlling the activity of cells of the immune system) that the people studied secreted to defend themselves against these pathogens and coordinate the immune response to fight them. The conclusion was clear: Of all the environmental factors examined, smoking had the greatest impact on the immune response.
One of the authors, Violaine Saint-André, a researcher at the Pasteur Institute in Paris, explained this in a press conference organized by Nature Smoking alters the body’s defenses in two ways. Affects the “innate or natural” immunitythis is the body’s innate ability to destroy any type of potentially harmful microorganisms, and also modifies the so-called “adaptive immunity (mediated by lymphocytes), which produces specific antibodies against each threat.
The body has a “memory” of smoking
The scientists found that although the change in innate immunity is “transient” and is lost after quitting smoking, Damage to adaptive immunity persists and the amount of cytokines released during an infection or other health problem remains altered for up to 10 or 15 years after a person quits tobacco.
They observed that There is a relationship between the years a person has smoked and the number of cigarettes smoked with the duration of damage to adaptive immunity. After already known factors such as age, gender, genetics, body mass index or cytomegalovirus infection (a type of herpes), “we now show that smoking is another major modifier of the immune system,” Saint-André added.
“When a person quits smoking, they recover well some of the innate immunity, but not the adaptive immunity. This suggests.” The immune system has a memory of having smoked continuouslywhich has an important impact on smokers,” says África González-Fernández, professor of immunology at the Spanish University of Vigo, in a reaction collected by the Science Media Center (SMC) platform.
This study “helps to explain possible changes in immune response that we commonly observe in smokers reaching age 60 who are suspected of having a secondary immunodeficiency associated with chronic obstructive pulmonary disease (COPD) and who have low concentration of antibodies is observed,” said Marcos López Hoyos, president of the Spanish Society of Immunology (SEI), in another reaction from the SMC.
What are the long-term consequences?
The changes in the immune system caused by smoking can manifest themselves in the long term in a increased risk of developing autoimmune diseases, allergies or cancer, noted another of the authors, Darragh Duffy, also associated with Pasteur, at the same briefing. “Our conclusions point to this in the short term Any disease worsens in a person who smokes “Compared to someone who doesn’t smoke or has smoked and where there is inflammation, the symptoms will last longer and there is a greater chance of complications and chronicity of the disease,” he added.
The authors recognized that a limiting aspect of the work is the lack of genetic diversity of the individuals studied, and the fact is that all studies were carried out on peripheral blood cells and there are no data on how tobacco exposure affects them even at the respiratory level (e.g. mucous membrane and bronchoalveolar fluid).
In addition to the findings of the research itself, these results “will help to better understand the factors underlying the risk of contracting infections and other diseases related to the immune system, such as cancer,” the scientists noted. When asked what message they would send to citizens as a result of this research, the researchers were clear: “There is never a good time to start smoking and the right time to quit smoking is now“.