Smokers, even if they averaged less than one cigarette a day over their entire lifetime, were 64 percent more likely to die early than those who never smoked, according to research from the National Cancer Institute.
The risk jumped to 87 percent for those who averaged one to 10 cigarettes a day, identified as “low-intensity” smokers.
Low-intensity smokers who quit had a lower risk of early death than current low-intensity smokers.
That risk fell further the younger smokers were when they quit.
Lung cancer was the leading cause of death for smokers in the study, with low-intensity smokers having a 12 times higher risk of dying from lung cancer than non-smokers. Even people who smoked less than a cigarette per day had nine times higher risk of early death from lung cancer.
The risk of early death from emphysema and other respiratory diseases was six times higher in low-intensity smokers. The risk from cardiovascular disease was one and a half times higher than in people who never smoked.
Researchers used data from more than 290,000 adults, ages 59 to 82 enrolled in the National Institutes of Health-AARP Diet and Health Study. Participants reported their smoking patters from before they were 15 until age 70. Over all the years they smoked, 159 said they smoked less than a cigarette a day. And nearly 1,500 said they smoked between one and 10 cigarettes a day.
Despite most participants being older whites, study authors wrote that they predict the results would be similar among other groups. “All smokers, no matter how few cigarettes they smoke per day, should be encouraged and assisted to quit,” wrote authors of the study, which appeared Monday in the Journal of the American Medical Association-Internal Medicine.
More study is needed about differences in the risk of death for people who smoked every few days, ever other day or once a week, authors wrote.
The results could have health implications for people who are low-intensity cigarette-smokers who also use e-cigarettes or other tobacco products, according to researchers.
Tobacco use is the No. 1 preventable cause of death in the United States, killing more than 480,000 Americans and costing about $170 billion in health-care expenses each year. According to the American Heart Association, it contributes to the buildup of plaque in the arteries, which can lead to heart attacks and strokes.