Survival effects of smoking. New research from the Pasteur Institute

In mid-February, the Pasteur Institute in Paris published the results of a study on how the immune system works in people who quit smoking even many years ago. The aim of the study was to see if there is and how the body's long-term memory of the consequences of smoking works. It turns out that certain defense mechanisms that were altered during addiction are not subject to regeneration and change for many years and the immune system against microorganisms works less effectively in former smokers. Although with different sensitivity in individuals.

The authors of the study, from the Department of Translational Immunology at the Pasteur Institute, sought to clarify which factors such as age, gender, genes, and BMI have the greatest impact on immune function and compare them with factors such as body mass index, current and past smoking, number of hours of sleep, physical activity, childhood diseases, vaccinations, and place of residence. The study was conducted with 1,000 volunteers, considered healthy, currently non-smokers for several to several years. The researchers took blood samples from the participants and exposed them to various microorganisms, viruses and bacteria. They then observed the immune system's response by measuring the levels of secreted cytokines. As for former smokers, analysis of the data showed that the inflammatory response - triggered spontaneously when infected with a pathogen - was increased, but the activity of certain cells involved in immune memory was also altered. The study found that smoking interferes with innate immunity mechanisms and may also alter certain mechanisms of acquired immunity.

Comparing the immune response, smokers and ex-smokers found that the inflammatory response quickly returns to normal after quitting smoking, but the effect on acquired immunity persists for 10-15 years. Thus, the long-term effect of smoking on immune responses has been demonstrated. The immune system seems to remember the effects of addiction for a long time. The study concluded that the long-term effect of smoking on the immune response is linked to differences in DNA methylation - possibly modifying the expression of genes involved in immune cell metabolism.

Methylation is responsible for many processes involved in the development of organisms - in particular, the production and maintenance of appropriate tissue specification. The final conclusion of the study therefore confirms that smoking has a long-term effect on the immune system, and therefore may affect health loss that will not be directly associated with a former addiction.