People who quit smoking experience significant improvements in life expectancy in just a few years, as revealed by a recent study conducted by researchers from the University of Toronto affiliated with Unity Health Toronto.
Published in NEJM Evidence, the study demonstrates that individuals who quit smoking before the age of 40 can anticipate a lifespan nearly equivalent to those who never smoked. Moreover, those who cease smoking at any age approach the life expectancy of non-smokers within a decade of quitting, with approximately half of this benefit realized within three years.
“Quitting smoking yields remarkable and rapid reductions in the risk of mortality,” remarked Prabhat Jha, a professor at U of T’s Dalla Lana School of Public Health and Temerty Faculty of Medicine. Jha, who serves as the executive director of the Centre for Global Health Research at Unity Health Toronto, emphasized the effectiveness of smoking cessation.
The observational study encompassed 1.5 million adults across four countries: the U.S., UK, Canada, and Norway, over a span of 15 years. Smokers aged 40 to 79 exhibited nearly a threefold increased risk of mortality compared to non-smokers, resulting in an average life expectancy loss of 12 to 13 years.
Former smokers, however, reduced their risk of death to 1.3 times that of non-smokers, representing a 30% higher risk. Regardless of age, quitting smoking was associated with prolonged survival, with even those who quit for less than three years gaining up to six years in life expectancy.
“Many individuals believe it’s too late to quit smoking, especially in middle age,” noted Jha. “Yet, these findings challenge such assumptions. It’s never too late; the impact is swift, leading to risk reduction across major diseases and ultimately enhancing both longevity and quality of life.”
The research underscored that smoking cessation notably lowered the risk of mortality from vascular disease and cancer, with a somewhat lesser impact observed on mortality from respiratory disease, likely attributable to residual lung damage.
Despite a global decline in smoking rates by over 25% since 1990, tobacco remains a leading cause of preventable death, with approximately 60 million smokers in the four countries examined and over a billion worldwide.
Jha urged governments to intensify efforts to support smoking cessation, emphasizing that aiding smokers in quitting is among the most effective measures to enhance public health. Strategies such as increasing cigarette taxes and enhancing cessation support systems, including clinical guidelines and helplines, are crucial.
Canada, Jha noted, is overdue for a federal excise tax hike on cigarettes, while other nations could similarly decrease smoking prevalence through tax increases. Moreover, health care professionals should proactively encourage smokers to quit during interactions, emphasizing the efficacy of cessation while maintaining empathy and avoiding stigma, given the addictive nature of cigarettes.