An estimated 450,000 US deaths are expected this year from conditions attributed to cigarette smoking. Although the percentage of adults who smoke declined from 21% in 2005 to 11% in 2022, the annual death toll has been stable since 2005 and isn’t expected to decline until 2030, owing to an aging population of current and former smokers.
In 2022, based on a national survey, two thirds of the 28.8 million US adult smokers wanted to quit, and more than half tried quitting on their own or with the help of clinicians, but less than 9% succeeded in kicking the habit. The health benefits of quitting, summarized in a patient education handout from the American Cancer Society, include a lower risk for cancer, diabetes, and cardiovascular disease. Furthermore, the handout states, “quitting smoking can add as much as 10 years to your life, compared to if you continued to smoke.”
For my patients older than age 50 who are lifelong smokers, the qualifier “as much as” can be a sticking point. Although most recognize that continuing to smoke exposes them to greater health risks and are willing to undergo lung cancer screening and receive pneumococcal vaccines, a kind of fatalism frequently sets in. I’ve heard more times than I can recall some version of the declaration, “It’s too late for quitting to make much difference for me.” Many smokers think that once they reach middle age, gains in life expectancy will be too small to be worth the intense effort and multiple failed attempts that are typically required to quit permanently. Until recently, there were few data I could call on to persuade them they were wrong.
In February 2024, Dr. Eo Rin Cho and colleagues pooled data from four national cohort studies (United States, United Kingdom, Norway, and Canada) to calculate mortality differences among current, former, and never smokers aged 20-79 years. Compared with never smokers, lifelong smokers died an average of 12-13 years earlier. However, quitting before age 50 nearly eliminated the excess mortality associated with smoking, and in the 50- to 59-year-old age group, cessation eventually reduced excess mortality by 92%-95%. Better yet, more than half of the benefits occurred within the first 3 years after cessation.
At first glance, these estimates may seem too good to be true. A few months later, though, a different research group, using data from a large cancer prevention study and 2018 US population census and mortality rates, largely confirmed their findings. Dr. Thuy Le and colleagues found that quitting at age 35, 45, 55, 65, or 75 years resulted in average life gains of 8, 5.6, 3.5, 1.7, and 0.7 years, respectively, relative to continuing to smoke. Because no patient is average, the analysis also presented some helpful probabilities. For example, a smoker who quits at age 65 has about a 1 in 4 chance of gaining at least 1 full year of life and a 1 in 6 chance of gaining at least 4 years. In other words, from a life expectancy perspective alone, it’s almost never too late to quit smoking.
Dr. Lin is a family physician and Associate Director, Family Medicine Residency Program, Lancaster General Hospital, Lancaster, Pennsylvania. He blogs at Common Sense Family Doctor. He has disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.