Smoking: more damage
STUDY: ADAPTIVE IMMUNITY COMPROMISED FOR YEARS – EVEN DECADES This could affect risk of infections, cancer, autoimmune diseases.
Researchers are still discovering how smoking continues to harm people’s health even years after they quit, with a new study this week revealing tobacco’s lasting effect on the immune system.
Despite the tobacco industry long fighting to conceal the dangers of smoking, tobacco is now known to kill more than eight million people globally a year, according to the World Health Organisation.
But the myriad of ways the habit damages bodies are still coming to light.
The new study, published in the journal Nature, found that smoking alters the immune system for far longer than previously thought.
It particularly highlighted changes to what is called adaptive immunity, which is built up over time as the body’s specialised cells remember how to fight back against foreign pathogens they have encountered before.
The findings were based on analysing blood and other samples taken from 1 000 healthy people in France, starting from more than a decade ago.
Smoking was found to have more influence on adaptive immunity than other factors, such as amount of sleep or physical activity, the researchers said.
The study also confirmed previous research which has shown smoking’s effect on “innate immunity,” which is the body’s first line of defence against invading pathogens.
While innate immunity rebounded immediately after people stopping smoking, adaptive immunity remained effected for years, even decades, the study said.
The sample size was too small to give a precise timeline for how long these changes last. The researchers emphasised that the effect does wear off.
Of course, it is still better “for long term immunity to never start smoking,” lead study author Violaine Saint-Andre of France’s Pasteur Institute said.
The researchers could not say for sure what consequences these changes may have on health. But they hypothesised that it could affect people’s risk of infections, cancer or autoimmune diseases.
Another study, published last week in the journal NEJM Evidence, found that when people quit smoking, it took 10 years for their average life expectancy to return to the same level as non-smokers. –