Even low-intensity smokers at increased risk of earlier death: study

People who consistently puff on 10 or less cigarettes per day over their lifetime still have higher risks of death than individuals who never smoke, a new U.S. study said Monday.

"The results of this study support health warnings that there is no safe level of exposure to tobacco smoke," lead author Maki Inoue-Choi of the U.S. National Cancer Institute said in a statement.

To better understand the effects of low-intensity smoking on death, the researchers analyzed data on over 290,000 adults who completed a questionnaire on their smoking behaviors in 2004-2005.

All participants were age 59 to age 82 at the start of the study. Of these people, over 22,000 are current smokers, over 156,000 are former smokers, and over 111,000 never smoked.

It found that people who consistently smoked an average of less than one cigarette per day over their lifetime had a 64 percent higher risk of earlier death than never smokers, and that those who smoked between one and 10 cigarettes a day had an 87 percent higher risk of earlier death than never smokers.

Risks were lower among former low-intensity smokers compared to those who were still smokers, and risk fell with earlier age at quitting.

"Together, these findings indicate that smoking even a small number of cigarettes per day has substantial negative health effects and provide further evidence that smoking cessation benefits all smokers, regardless of how few cigarettes they smoke," said Inoue-Choi.

The findings were published in the U.S. journal JAMA Internal Medicine. Enditem