Cigarette smoke contains thousands of toxic chemicals that damage nearly all organs and are associated with various health issues, including cancers, stroke, heart disease, and lung disease.
Quantifying the impact of smoking on life expectancy and the benefits of cessation is essential for encouraging smokers to quit. Previous studies have estimated these effects, but many were conducted over a decade ago and often excluded a significant demographic: smokers aged 65 and older.
A new study- published by Elsevier- is the first to quantify the impact of quitting smoking for individuals older than 65. Scientists found that quitting smoking even as late as 75 years of age can meaningfully increase a person’s life expectancy.
The research evaluates the impact of smoking on life expectancy at 10-year intervals from ages 35 to 75, highlighting the potential benefits of quitting. The findings indicate that while the advantages of cessation decrease with age, significant health gains are still possible for older individuals.
Thuy T.T. Le, PhD, who conducted the study with co-investigators David Mendez, PhD, and Kenneth E. Warner, PhD, all affiliated with the Department of Health Management and Policy at the University of Michigan School of Public Health, explains, “We have seen a remarkable decline in young adult smoking over the past decade. However, rates among older adults who smoke have remained stagnant, and to our knowledge, no research has established the benefits of quitting. We wanted to show that stopping smoking is beneficial at any age and provide an incentive for older people who smoke to quit.”
Scientists used all-cause mortality relative risks from smoking to create life tables illustrating the benefits of quitting at various ages. They found that individuals who smoke and have done so throughout adulthood can expect to lose an average of 9.1 years at age 35, 8.3 years at age 45, 7.3 years at age 55, 5.9 years at age 65, and 4.4 years at age 75 compared to non-smokers.
However, if they quit smoking at these ages, they can avoid an average loss of 8.0, 5.6, 3.4, 1.7, and 0.7 years, respectively. The likelihood of gaining at least one additional year of life is 23.4% for those who quit at age 65 and 14.2% for those who quit at age 75.
This study reinforces the critical finding that quitting smoking is the most effective way to improve life expectancy. It revealed that nearly 10% of individuals who quit at age 65 can gain at least 8 additional years compared to those who continue smoking.
Similarly, 8% of those who quit by age 75 can gain at least 4 years. For a 75-year-old smoker, life expectancy is around 9 years; quitting can lead to an average gain of 0.7 years (7.8% of their life expectancy), with about 8% regaining at least 4 years (45% of their life expectancy).
Dr. Warner concludes, “The cessation benefit is not limited to young and middle-aged adults who smoke; this study demonstrates its applicability to seniors as well. While the gains from quitting at older ages may seem low in absolute values, they represent a large proportion of an individual’s remaining life expectancy.”
Journal Reference:
- Thuy T.T. Le, David Mendez, Kenneth E. Warner et al. The Benefits of Quitting Smoking at Different Ages. The American Journal of Preventive Medicine. DOI: 10.1016/j.amepre.2024.06.020