A new study suggests quitting smoking before turning 35 may lower your mortality rate

Are you one of those who tried to quit smoking but then failed? Well, it still may not be too late for it.

According to a large-scale study, those who quit smoking before the age of 35 have similar mortality rates within a given time period to those who have never smoked. This can be a wake-up call for people younger than 35 to reconsider quitting.

If you've already turned 35, no worries. The research also demonstrated substantial benefits for those who quit smoking at later ages.

The thing is, the death rates of those who quit smoking after the age of 35 were relatively higher than the younger quitters. To exemplify, former smokers who quit between the ages of 35 and 44 had a 21% higher rate of mortality from any cause compared to "never smokers." Those who quit between the ages of 45 and 54, on the other hand, showed a 47% higher all-cause mortality rate.

"Among men and women from diverse racial and ethnic groups, current smoking was associated with at least twice the all-cause mortality rate of never smoking," wrote researchers in the study paper. "Quitting smoking, particularly at younger ages, was associated with substantial reductions in the relative excess mortality associated with continued smoking."

Employing data from more than 550,000 people

Researchers gathered data from the U.S. National Health Interview Survey and the National Death Index and analyzed survey data from more than 550,000 adults who completed questionnaires between January 1997 and December 2018. The subjects, who were aged between 25 and 84 at the time of recruitment, were comprised of current smokers, former smokers, and the so-called "never smokers," which refers to those who smoked less than 100 cigarettes in their whole lives.

By the end of 2019, approximately 75,000 of these study participants were dead, according to the National Death Index. Current smokers demonstrated a considerably higher all-cause mortality rate as well as increased rates of death from cancer, heart disease, and lung disease when compared to never smokers.

In a commentary on the study, John P. Pierce, a professor emeritus in the Department of Family Medicine and Public Health at the University of California, San Diego, stated that the age of 35 as a deadline could motivate young smokers to quit.

"Without a proximal goal, it is tempting for smokers to abandon a quit attempt with cognitions such as 'I don't really need to do it just now.' The study … provides needed data to set a motivating proximate goal of quitting smoking before age 35 years," he wrote.

The results of the large-scale study were published in the journal JAMA Network Open on October 24.

Abstract:

Importance: Patterns of cigarette smoking and smoking cessation vary considerably across demographic groups in the US, but there is limited evidence on whether the hazards of smoking and benefits of quitting vary across these groups. Population-specific evidence on the benefits of quitting smoking may motivate cessation among groups historically underrepresented in medical research.

Objective: To quantify the association between smoking, smoking cessation, and mortality by race, ethnicity, and sex.

Design, Setting, and Participants: This nationally representative, prospective cohort study used data from the US National Health Interview Survey collected via questionnaire between January 1997 and December 2018 among adults aged 25 to 84 years at recruitment. Participants were followed up for cause-specific mortality through December 31, 2019.

Exposures: Self-reported smoking status at recruitment, age at quitting smoking, and years since quitting smoking.

Main Outcomes and Measures: The main outcomes were all-cause mortality and mortality from cancer, cardiovascular disease, and lower respiratory disease. Adjusted mortality rate ratios comparing never, former, and current smokers were calculated using Cox proportional hazards regression. Weighted analyses were conducted by race, ethnicity, and sex as reported by participants.

Results: Among the 551 388 participants in the main analyses, the mean (SD) age at recruitment was 48.9 (15.3) years; 307 601 (55.8%) were women, 87 207 (15.8%) were Hispanic, 75 545 (13.7%) were non-Hispanic Black, 355 782 (64.5%) were non-Hispanic White, and 32 854 (6.0%) identified as other non-Hispanic race and ethnicity. There were 74 870 deaths among participants aged 25 to 89 years during follow-up (36 792 [49.1%] among men; 38 078 [50.9%] among women). The all-cause mortality rate ratio (RR) for current vs never smoking was 2.80 (95% CI, 2.73-2.88) overall. The RRs were similar by sex but varied by race and ethnicity: Hispanic, 2.01 (95% CI, 1.84-2.18); non-Hispanic Black, 2.19 (95% CI, 2.06-2.33); non-Hispanic White, 3.00 (95% CI, 2.91-3.10); and other non-Hispanic race and ethnicity, 2.16 (95% CI, 1.88-2.47). When comparing those who quit smoking before age 45 years with never smokers, all-cause mortality RRs were 1.15 (95% CI, 1.03-1.28) among Hispanic individuals, 1.16 (95% CI, 1.07-1.25) among non-Hispanic Black individuals, 1.11 (95% CI, 1.08-1.15) among non-Hispanic White individuals, and 1.17 (95% CI, 0.99-1.39) among other non-Hispanic individuals.

Conclusions and Relevance: In this prospective cohort study, among men and women from diverse racial and ethnic groups, current smoking was associated with at least twice the all-cause mortality rate of never smoking. Quitting smoking, particularly at younger ages, was associated with substantial reductions in the relative excess mortality associated with continued smoking.