Occasional smoking is still harmful, a new study says.  Even just one cigarette a day can increase risk for an early death.

A research published in JAMA Internal Medicine says that those who smoked an average of less than one cigarette per day still have a very high risk of dying early.

'No Safe Level Of Exposure To Tobacco Smoke'

The study tracked more than 290,000 Americans aged 59 to 82 to assess the risks of "light" smoking - meaning 10 cigarettes a day or less.  What they found was people who smoked an average of less than one stick a day had a 64 percent higher risk of suffering an early death of any cause, while those who smoke 1 to 10 cigarettes a day are 87 percent more likely to die from all causes compared to those who did not smoke at all.

Lead author, Maki Inoue-Choi, a staff scientist at the National Cancer Institute's Division of Cancer Epidemiology and Genetics, said: "There is no safe level of cigarette smoking.  Even smokers who consistently smoked less than one cigarette per day were more likely to die in our study than never smokers."

It's Never Too Late To Quit Smoking

Inoue-Choi's team noted that there is very little benefit from cutting back from two packs a day to half a pack.  The investigators also found that those who remained to be light smokers in their lifetime are more likely to die early compared to those who quit.  The study only shows that the younger a smoker quits, the lower the death risk. 

"Together, these findings indicate that smoking even a small number of cigarettes per day has substantial negative health effect, and provide further evidence that smoking cessation benefits all smokers, regardless of how few cigarettes they smoke," the lead author concluded.