A team of researchers has said that smokers who give up cigarettes, even at 75, could be boosting their life expectancy, and that it’s never too late to make healthy lifestyle choices.
The estimates, led by a team from the University of Michigan School of Public Health, suggest that people aged between 35 and 75 who had previously smoked have added considerable time back to their life expectancy by giving up the habit.
Using publicly available, nationally representative health data, the researchers performed a series of calculations to estimate the average number of years lost due to smoking and the average years gained by quitting smoking at various ages, reports Science Alert.
The quitting ages considered were 35, 45, 55, 65 and 75.
The life expectancy of those who kicked the habit was compared with those who kept smoking at these specific ages and those who had never smoked at these ages, and these estimates were graphed based on probability.
Compared with those who never smoked, individuals who smoked at age 35 and continued smoking throughout the remainder of their lives were predicted to lose about nine years of life on average (23% of their total life expectancy).
By contrast, people who stopped smoking at 35 only had about a year difference between their life expectancy and that of those who never smoked. In other words, they had regained, on average, about eight years of expected life, according to the paper, published in the American Journal of Preventive Medicine.
The findings are supported by a previous study from researchers in Canada and Norway, which found that if a person can stop smoking for a decade, they can potentially avert a decade of life lost. But even at older ages there were benefits to life expectancy.
The current research agrees. Individuals who smoked at 75 and who continued for the rest of their lives were predicted to lose about 4.4 years of life on average (nearly 50% of their life expectancy at this age).
Based on probability curves, however, the chances of gaining at least one year of life among those who quit smoking at 65 and 75 are 23% and 14%, respectively.
“These findings may be valuable for clinicians seeking scientific evidence to motivate their patients who smoke to quit,” said the researchers.
Study details
The Benefits of Quitting Smoking at Different Ages
Thuy T.T. Le, David Mendez, Kenneth E. Warner.
Abstract
Introduction
Quantifying the impact of smoking on life expectancy and the potential benefits of smoking cessation is crucial for motivating people who smoke to quit. While previous studies have attempted to estimate these effects, they were conducted more than a decade ago and did not include a significant demographic, people over 65 years old who smoke.
Methods
Mortality rates by age and smoking status were calculated using mortality relative risks derived from Cancer Prevention Study II, 2018 National Health Interview Survey smoking prevalence data, 2018 U.S. population census data, and 2018 U.S. mortality rates. Subsequently, life tables by smoking status—never, current, and former—were constructed. Life expectancies for all three smoking statuses, including those of individuals who had quit smoking at various ages ranging from 35 to 75, were then compared. Additionally, probability distributions of years lost due to smoking and years gained by quitting smoking at different ages were generated. Analyses were conducted in 2023.
Results
Compared to people who never smoked, those who smoke currently, aged 35, 45, 55, 65, or 75 years, and who have smoked throughout adulthood until that age, will lose, on average, 9.1, 8.3, 7.3, 5.9, and 4.4 years of life, respectively, if they continue to smoke for the rest of their lives. However, if they quit smoking at each of these ages, they will avoid an average loss of 8.0, 5.6, 3.4, 1.7, and 0.7 years. The chances of gaining at least 1 year of life among those who quit at age 65 and 75 are 23.4% and 14.2%, respectively.
Conclusions
Quitting smoking early will avoid most years otherwise lost due to smoking. Even those who quit at ages 65 and above can still meaningfully increase their life expectancy.
Science Alert article – Quitting Smoking Even at 75 Can Increase Life Expectancy, Study Finds
See more from MedicalBrief archives:
Public Health England: Stopping smoking – What works?
Quitting smoking associated with lower risk of CVD
Smoking damage to immune system lasts for years – French study
Stopping smoking before 45 can wipe out 87% of lung cancer risk