Adaptive immunity, which is built over time with infections, remains damaged for years after quitting smoking, according to two studies.
:quality(50)/2023/07/06/64a68815cd1a7_placeholder-36b69ec8.png)
Published
Reading time: 1 min
:quality(50)/2024/02/14/080-hl-mcohen-2201175-65ccecc70ff86207075413.jpg)
When you stop smoking, the counters take a long time to return to zero. Two recent studies demonstrate the lasting effects of smoking on health. Our immunity, in particular, seems even more damaged than expected. “Smoking modifies adaptive immunity in a persistent manner”concludes a study published Wednesday February 24 in the journal Nature.
This work marks an important advance in understanding the deleterious health effects of smoking which, according to the World Health Organization (WHO), kills some eight million people per year worldwide. It highlights an element hitherto ignored: adaptive immunity, which is built over time with infections, remains damaged for years after stopping smoking.
People followed for ten years
These conclusions are based on a sample of one thousand people. These were selected more than ten years ago, as part of a project led by the Pasteur Institute in Paris, and their immunity was then regularly studied via various tests, particularly blood tests. This type of project, called a cohort project, is very robust for assessing how different factors influence health and metabolism over time.
And, in this case, it is smoking which stands out for its influence, more than other factors such as sleep time or the degree of physical activity, according to researchers led by biologist Violaine Saint-André. This is not entirely new. We knew that smoking affects “innate” immunity – that which is common to everyone – by aggravating inflammatory responses.
The study confirms this, finding that this effect disappears immediately after stopping smoking. But, and this is the great novelty, it is not the same thing for acquired immunity. This remains, for certain individuals, affected for years, even decades, after stopping smoking even if the sample is too small and the reactions too variable to put forward a precise average duration.