By Kristina Dougherty

PHILADELPHIA (CBS) – Smoking just one cigarette a day leads to a higher risk of earlier death, according to a study.

Researchers found 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 those who never smoke.

Smoke even more than one cigarette a day? The study found those who smoke between one and 10 cigarettes had an 87 percent risk of earlier death than nonsmokers.

The study was done by researchers at the National Cancer Institute.

They say the risks were lower among former low-intensity smokers compared to those who continued to smoke. The risk also fell if a person quit at an earlier age.

Researchers say, “Those who consistently averaged less than one cigarette per day over their lifetime had nine times the risk of dying from lung cancer than never smokers.”

The researchers found the risk of dying from lung cancer was 12 times higher for those who smoked between one and 10 cigarettes a day.

“People who smoked between one and 10 cigarettes a day had over six times the risk of dying from respiratory diseases than never smokers and about one and half times the risk of dying of cardiovascular disease than never smokers.”

For their study, scientists analyzed data on over 290,000 adults in the NIH-AARP Diet and Health Study.

Low-intensity smoking was defined as 10 or fewer cigarettes per day. All participants were 59 to 82 years old at the start of the study.

Researchers say the participants were asked about their smoking behaviors during nine periods across their lives, beginning with before their 15th birthday until after they reached the age of 70.

“The results of this study support health warnings that there is no safe level of exposure to tobacco smoke,” said Maki Inoue-Choi, Ph.D., NCI, Division of Cancer Epidemiology and Genetics, and lead author of the study.

“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.”

Kristina Dougherty