Quitting smoking increases life expectancy even for seniors

Quitting smoking is a popular New Year’s resolution for many people looking to improve their health, but for those who 65 or over, there may be an attitude of ‘the damage is already done’. Now, researchers from the University of Michigan School of Public Health have discovered that although the benefits of quitting smoking diminish with age, there are still substantial gains for older individuals.

Cigarette smoke contains thousands of toxic chemicals that harm almost all organs in the body and are linked to numerous cancers, stroke, heart disease and lung disease. Previous studies have consistently demonstrated that quitting smoking at any age yields health benefits, but this latest study, published in the American Journal of Preventive Medicine, is the first to quantify the impact of quitting smoking for individuals older than 65.

“We have seen a remarkable decline in young adult smoking over the past decade,” said Dr Thuy TT Le, who conducted the study with co-investigators Dr David Mendez and Dr Kenneth E Warner. “However, rates among older adults who smoke have remained stagnant and to our knowledge, no research had established the benefits for them 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.”

The investigators used all-cause mortality relative risks due to smoking to build life tables that show the benefits of quitting smoking at different ages, reporting the expected life years lost to individuals who smoke at various ages compared to those who never smoked. Compared to people who never smoked, those who smoke currently (aged 35, 45, 55, 65 or 75) and who have smoked throughout adulthood 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, respectively. The chances of gaining at least one year of life among those who quit at age 65 are 23.4% and 14.2%.at age 75.

The results showed that nearly 10% of smokers who quit at age 65 gain at least eight years of life compared to those who do not. Additionally, 8% of those who quit by age 75 gain at least four years of life compared to those who continue smoking. Life expectancy for a 75-year-old person who smokes is nine years. If that person quits, they will regain (on average) 0.7 years (7.8% of the life expectancy), and about 8% of those individuals who quit will regain at least four years of life (45% of the life expectancy). The study thus supports the idea that quitting smoking is the single best thing people can do to enhance their life expectancy.

“The cessation benefit is not limited to young and middle-aged adults who smoke; this study demonstrates its applicability to seniors as well,” Warner said. “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.”

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