It's never too late to quit smoking. Researchers have found in a study that quitting smoking before the age of 40 could bring a smoker's life expectancy comparable to that of non-smokers.

The study further unveils that individuals who quit smoking, regardless of age, can achieve a life expectancy similar to non-smokers within approximately 10 years after quitting, and nearly half of this benefit can be noticed within just three years.

These findings published in the journal NEJM Evidence were based on a large-scale study conducted by researchers from the University of Toronto. The study involved around 1.5 million adults from the U.S., UK, Canada, and Norway who were followed for 15 years.

"Smokers between the ages of 40 and 79 had an almost three-fold risk of dying compared to those who never smoked, meaning on average they lost 12 to 13 years of life. Former smokers lowered their risk of death to 1.3-fold (or 30 percent higher) compared to non-smokers. Stopping smoking at any age was associated with longer survival, and even those who quit for less than three years gained up to six years in life expectancy," the news release stated.

The researchers noted that quitting smoking at any age, particularly at a younger age, reduces the excess risk of overall mortality and risk of death from vascular, respiratory, and neoplastic diseases (conditions that cause tumor growth).

"Quitting smoking is ridiculously effective in reducing the risk of death, and people can reap those rewards remarkably quickly," said a study author Prabhat Jha. "Many people think it's too late to quit smoking, especially in middle age. But these results counter that line of thought. It's never too late, the impact is fast and you can reduce risk across major diseases, meaning a longer and better quality of life," he added.

Estimates show that there are about 60 million smokers in the four countries involved in the study, and more than a billion smokers worldwide. Although the global rate of smoking has reduced by more than 25 percent since 1990, tobacco remains a leading cause of preventable death.

The researchers hope their findings will prompt governments to intensify their efforts to support people who want to stop smoking.

"Helping smokers quit is one of the most effective ways to substantially improve health. And we know how to do that, by raising taxes on cigarettes and improving cessation supports," Jha added.

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