"LOTS! A new study (coordinated by the University of Manitoba and involving 10 sites in the United States and Canada) proves for the first time that smokers who quit wind up with healthier lungs, no matter how long they had smoked. The study involved more than 5,800 smokers who were victims of chronic obstructive lung disease: a combination of emphysema and bronchitis (the fourth leading cause of death in the U.S.A.).

"The study was the first proof that if you stop smoking at any age, you will have healthier lungs.

"It was the largest study ever conducted on the prevention of lung disease and showed without a doubt that quitting smoking is the most effective way of preventing lung function decline.

"So there you have it, conclusive proof the it worth quitting no matter how old you are or how long you have smoked for."