(NEW YORK) — Just 100 cigarettes over the course of someone’s life may be enough to raise their risk of heart disease and death, a new study suggests.
Researchers at Johns Hopkins University, who looked at the smoking habits of more than 300,000 adults for almost 20 years, found that men and women who smoked as few as two cigarettes daily had a 60% increased risk of death from any cause compared to those who never smoked.
Additionally, the smoking group had a 50% higher risk of heart disease, according to the study published Tuesday in the journal PLOS Medicine.
“Tobacco use is a very well-established risk factor for heart disease,” said Dr. Jennifer Miao, a cardiologist at Yale University and an ABC News Medical Unit fellow. “It really damages the blood vessel lining and it accelerates the development of plaques and coronary artery disease.”
Smoking is also linked to heart rhythm issues, such as atrial fibrillation and stroke, Maio added.
Cutting back on cigarette use may not be enough to reverse the harm, the study found. Although current smokers had a higher risk of death than former smokers, former smokers still had an elevated risk of heart disease more than 20 years after they had kicked the habit, according to the study.
Data from the American Lung Association shows that adult smoking in the U.S. has dropped from about 42% in 1965 to roughly 12% in 2022 — a decline of more than 70%.
However, the number of people smoking fewer than 15 cigarettes per day increased 85% during the same period.
Americans should be counseled to quit smoking altogether rather than just cutting back, Dr. Erfan Tasdighi, co-author of the study and internal medicine physician at Rutgers New Jersey Medical School, told ABC News.
“We actually have the evidenc. … to say that even less than one cigarette a day can increase different multiple cardiovascular outcomes, and it’s not something that’s clinically insignificant,” Tasdighi said.
Miao acknowledged how difficult it can be for patients to go completely smoke-free.
“It’s very, very important for us as clinicians to acknowledge that it’s a lot easier said than done,” she said.
Miao suggested that physicians identify who is having a difficult time stopping tobacco use and get them connected with the appropriate resources and medical therapies available for smoking cessation efforts.
The benefit of quitting smoking is most substantial in the first ten years after quitting, the study suggested. However, researchers say it takes time for the body to recover and reach the level of someone who never smoked.
Tasdighi emphasized that this doesn’t mean cessation doesn’t have immediate effects.
“It’s important that people know that when they stop smoking, their risk goes down immediately and significantly,” he said.
Miao agreed, adding that the study’s most important takeaway is that “it’s important to quit smoking early on, and no amount of smoking is without risk and health consequences.”
It’s not just patients who should heed the results of this study, the authors stressed. Physicians should also consider changing the way they inquire about smoking because the number of packs someone smokes per year is not necessarily predictive of long-term health risks, they said.
“Clinicians need a more nuanced approach that incorporates other ways to identify and quantify cigarette use, like smoking status and smoking intensity,” Miao said, noting that whether it’s smoking one cigarette a day or one a week, no amount of smoking is safe, and quitting remains the best thing someone can do for their health.
To learn more about quitting smoking, call 1-800-QUIT-NOW or make an appointment with your health care provider.
Radhika Malhotra, MD, is an internal medicine-preventive medicine resident at Rutgers New Jersey Medical School and a member of the ABC News Medical Unit.
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