Scientists have found that smoking has harmful effects on the immune system even years after quitting.

According to a new study, smoke It has long-term effects on the immune system. Scientists from the French Pasteur Institute found that years after quitting tobacco, its effects on the body’s immune defense persist. The study was published Wednesday in the scientific journal Nature.

Researchers have begun studying what other factorsin addition to age, gender and genetics, influence how the body defends itself against external invaders.

They exposed blood samples from 1,000 healthy people to viruses and bacteria. they watched their immune responses, taking into account 136 variables such as body mass index (BMI), smoking, sleep and exerciseamong other things.

Three variables were identified: smoking, latent cytomegalovirus infection (an asymptomatic virus of the herpes family) and BMI.

The authors explained that current smokers have increased inflammatory response when they were stimulated with bacteria that disappeared when they quit smoking, but the effects of tobacco on the response of T cells, cells that help protect against disease, continued years after they quit smoking.

Long-term effects on immunity

“A comparison of immune responses in smokers and former smokers showed that the inflammatory response quickly returned to normal levels after smoking cessationwhile the effects on adaptive immunity persisted for 10 to 15 years,” Darragh Duffy, head of translational immunology at the Institut Pasteur and last author of the study, said in a statement.

“This is the first time that the long-term effects of smoking on immune responses have been demonstrated.” The researchers noted that smoking appears to cause persistent changes in the immune system influencing gene expression.

“This is an important discovery that clarifies the effect of smoking on the immunity of healthy people and also, by comparison, in the immunity of people suffering from various diseases,” said Violaine Saint-André, a computational biologist at the Pasteur Institute and lead author of the study.

Scientists note that more research needed in more diverse populations. Research may also help identify protein-gene interactions that are affected by smoking.

“These results provide new knowledge the impact of tobacco on human health and the role of modifiable environmental exposures on the variability of the immune response,” the authors conclude.