So smokers with “good genes” had a lower risk of COPD than those with “bad genes”.

Prof Martin Tobin, one of the researchers at the University of Leicester, said the genes seemed to affect the way the lungs grow and respond to injury.

But he told the BBC News website: “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.

“The strongest thing that people can do to affect their future health in terms of COPD and also smoking-related disease like cancer and heart disease is to stop smoking.”