When it comes to smoking, a new study says even one cigarette a day can greatly increase your chances of an early death.
Researchers at the National Cancer Institute compared the life expectancy of those who consistently smoked an average of less than one cigarette per day to those who never smoked in their lives. Those who smoked even at that low rate had a 64% higher risk of early death than those who never smoked at all. Those who smoked between one and 10 cigarettes every day over the course of their lifetimes had a 87% higher risk of dying early.
The new study, which was published Monday in the journal JAMA Internal Medicine, also examined the risk of lung cancer among those who smoked at low rates, or no more than one cigarette per day. They were still nine times more likely to die of lung cancer than those who never smoked at all, and the risk for those who smoked between one and 10 cigarettes per day was 12 times greater.
Though the study's scope is limited—the majority of the subjects were older and white, and were asked to recall habits as far back as age 15—it is one of the few to examine the health impacts of "low intensity" smoking. In fact, many smokers believe that smoking at low rates has a less intense impact on their health and life expectancy.
"The results of this study support health warnings that there is no safe level of exposure to tobacco smoke," said the study's lead author, Maki Inoue-Choi, National Cancer Institute's Division of Cancer Epidemiology and Genetics, in a statement.