The dangers of smoking cigarettes are well-documented, but why some people can smoke and stay healthy has remained somewhat of a medical mystery.
Now, a study out of the U.K. involving 50,000 participants indicates that's all thanks to genetics.
The study, funded by the Medical Research Council, found that many people who were able to ward off chronic obstructive pulmonary disease, or COPD, had a genetic mutation that strengthens the lungs and lessens the effects of smoking.
Still, one of the researchers from the University of Leicester told the BBC, "There doesn't appear to be any kind of magic bullet that would give anyone guaranteed protection against tobacco smoke — they would still have lungs that were unhealthier than they would be had they been a non-smoker."
COPD is a deadly disease, with 3 million deaths reported worldwide in 2012, according to the World Health Organization. Symptoms include breathlessness, chronic bronchitis and severe coughing. There is no cure.
And while this new research could possibly be a steppingstone to finding a cure for COPD, the researchers said they hope it will also lead to understanding how to treat the disease and prevent people from smoking in the first place.