How to live longer? quit smoking before 40

Good news for those trying to snuff out their smoking habit: in a new study, smokers who quit before turning 40 regained all of the years they would have presumably lost if they continued smoking.

Good news for those trying to snuff out their smoking habit: in a new study, smokers who quit before turning 40 regained all of the years they would have presumably lost if they continued smoking.

Smoking cuts at least 10 years off a person's lifespan, at least according to research. But a comprehensive analysis of health and death records in the US suggests that the damage isn't permanent, as long as you quit.

"Quitting smoking before age 40, and preferably well before 40, gives back almost all of the decades of lost life from continued smoking," says Dr. Prabhat Jha, head of the Centre for Global Health Research at St. Michael's Hospital and a professor in the Dalla Lana School of Public Health at the University of Toronto.

"That's not to say, however, that it is safe to smoke until you are 40 and then stop," Jha adds. "Former smokers still have a greater risk of dying sooner than people who never smoked. But the risk is small compared to the huge risk for those who continue to smoke."