A person who habitually smokes just one cigarette a day is nine times as likely to die from lung cancer as a non-smoker, and even if he or she quits at age 50, still has a 44 percent increased risk of premature death.
These findings, from a large study in JAMA Internal Medicine, provide further evidence that even the lowest levels of exposure to tobacco smoke are unsafe.
Researchers questioned more than 500,000 men and women about their lifetime smoking habits in 1995-96, and then questioned 290,215 of them again in 2004-5, when their average age was 71.
They gathered data about age of smoking initiation, number of cigarettes per day and age at cessation, plus information about race, education level, body mass index, alcohol intake and physical activity. They followed them through 2011.
After controlling for other health factors, the researchers found that compared with non-smokers, those who smoked one to 10 cigarettes a day throughout their lives had a 50 percent increased risk of cardiovascular disease and six times the risk of respiratory disease.
“There are a growing number of people only smoking a few cigarettes a day, and that’s the main reason for performing this study,” said the senior author, Neal D. Freedman, an epidemiologist with the National Cancer Institute. “Even these people benefit substantially from quitting smoking.”
Source: The New York Times
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