Even someone who has smoked for 15 years can make up lost ground by quitting, new research shows. A smoker who quits can, over time, face no greater risk of death than a person who has never smoked.
A study of more than 100,000 women shows that it takes about 20 years to even the ledger with the grim reaper after kicking the habit. But some partial benefits show up sooner. Within five years of quitting, a woman lessens her risk of dying from heart disease by half and from stroke by a fourth, compared with women who continue to smoke, researchers report in the May 7 Journal of the American Medical Association.
“This shows the harms of smoking are actually reversible over time,” says study coauthor Stacey Kenfield, an epidemiologist at Harvard School of Public Health in Boston.
To make these calculations, Kenfield and her colleagues tapped a study that tracked female nurses from 1980 to 2004 and regularly updated a database of the participants’ lifestyles, habits, health records and deaths. At the outset, about one-fourth of the volunteers had been smoking for 27 years on average and continued to smoke. Another quarter had quit after about 15 years of smoking. Nearly half had never smoked. By the end of the study, only 8 percent were still smoking.
Most smokers in the study averaged 10 to 15 cigarettes a day, Kenfield says.
The data suggest that the first few cigarettes each day account for the increased risk of death from heart disease and stroke. For such vascular diseases, Kenfield says, “mortality doesn’t go up that much with increasing cigarettes per day.”
Lung disease is another story. People who smoked roughly two packs a day were 40 times as prone to dying of lung cancer and 115 times as likely to die of congestive lung disease, such as emphysema, as nonsmokers, Kenfield and her colleagues found. The deadly effects of lung damage from smoking linger longer than damage to other organs, Kenfield concludes.
What’s more, the report turned up harsh warnings for people who begin smoking before age 17. This group was more likely to die during the study as were people who started smoking after age 26, other factors being equal. “It’s important to prevent kids from starting,” Kenfield says.
Other findings from the analysis show that a woman who quits smoking:
-lowers her risk of dying by 13 percent within the first five years of kicking the habit
-eliminates any risk of death by stroke or heart disease attributable to smoking in 20 years
-eliminates any risk of death from lung cancer related to smoking in 30 years.
This study suggests that quitting smoking at practically any point is beneficial, says pulmonologist Byron Thomashow of ColumbiaUniversityCollege of Physicians & Surgeons. Unfortunately, preventive approaches such as medication for smoking cessation, hotlines for quitting and public service announcements — all of which show effectiveness — are underfinanced in the United States, he says. “There’s a lot of evidence that even brief counseling of two or three minutes with a healthcare provider increases the quit rate by one-third,” he says. “You can make a real impact.”