WEDNESDAY, Nov. 20, 2013 (HealthDay News) -- Seniors who quit smoking cut their risk of death by heart disease much more quickly than previously thought, particularly if they were light-to-moderate smokers, a new study says.
Past estimates held that it takes smokers about 15 years after they quit to lower their risk of heart attack, heart failure or stroke to that enjoyed by people who never smoked, said lead author Dr. Ali Ahmed, senior study researcher. Ahmed is a professor of cardiovascular disease at the University of Alabama at Birmingham's School of Medicine.
But a new examination of 853 former smokers aged 65 and older found that many with a light-to-moderate smoking history can cut their risk in eight years or less, Ahmed said.
"Even though they quit only eight years ago, because they smoked less they were able to become like never-smokers in half the time," Ahmed said, citing findings he is scheduled to present Wednesday at the American Heart Association's annual meeting in Dallas.
Ahmed and his colleagues analyzed 13 years of medical information compiled by the U.S. National Heart, Lung, and Blood Institute to compare 853 people who had quit smoking 15 or fewer years ago with about 2,500 people who had never smoked. Half the smokers surveyed quit eight or fewer years before.
The researchers defined light smokers as people who had smoked less than 32 "pack years." This adds up to 3.2 packs a day for 10 years, or less than one pack a day for 30 years. About 37 percent of the former smokers fell into this category.
American Heart Association past president Dr. Gordon Tomaselli said that's a pretty generous definition of light smoking. "A pack a day for 32 years, that's not light," he said.
Light-to-moderate smokers who more recently quit had just a 14 percent chance of dying from heart disease, heart attack or stroke, compared with a 22 percent chance for former heavy smokers. People who never smoked had a 17 percent chance of death due to heart health problems.
These were somewhat surprising results, given the age of the patients and their smoking history, Tomaselli said. "The benefit was in a group we weren't sure would benefit as much as people who had smoked less or were younger," he said.
However, both light and heavy smokers continued to have a higher risk of death from other causes, including cancer and emphysema, Ahmed said.
Light smokers had a 29 percent chance of dying from a cause not related to their heart health, while heavy smokers had a 33 percent chance. Nonsmokers had a 22 percent chance, the investigators found.
"Yes, you get cardiovascular benefit [from quitting], but another part of your overall risk remains high even if you smoke at so-called light levels," Ahmed said.
Overall risk of death was 39 percent for nonsmokers, 43 percent for former light smokers and 55 percent for former heavy smokers in the study.
Ahmed and Tomaselli said smokers should heavily weigh the heart benefits of quitting. Heart disease is the number-one cause of death in the United States, taking nearly 600,000 lives a year, according to the U.S. Centers for Disease Control and Prevention.
"Cardiovascular disease is the biggest killer, and you can reduce that risk by smoking less and quitting early," Ahmed said. "Smoking is the single most preventable risk for heart disease."
Tomaselli said this study gives doctors a leg up when seniors argue that they've been smoking for too long and it's too late for them to quit.
"You can say to them with confidence that if you quit now, you can realize some benefits for cardiovascular health," Tomaselli said. "It's a reason even in older patients for doctors to be aggressive in recommending smoking cessation."
Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.
To find out more about smoking cessation, visit the U.S. Centers for Disease Control and Prevention.