0909 GMT August 21, 2019
The study, published on Thursday, suggests that so-called social smokers, who only light up on special occasions, may equally be at risk of heart disease compared with people on a daily cigarette habit.
The researchers involved in the study examined data on smoking habits, cholesterol levels and blood pressure for a nationally representative sample of 39,555 adults.
Most people said they did not smoke. About 17 percent were current smokers and about 10 percent were social smokers who did not have a daily habit but did regularly smoke in certain situations.
The study found that social smokers were more than twice as likely to have high blood pressure, also known as hypertension, compared with non-smokers. The social smokers, the study said, were 53 percent more likely to have elevated cholesterol.
Kate Gawlik, the lead study author and a researcher at the university, said, "These results provide strong evidence that smoking, regardless of amount, is an even stronger indicator of cardiovascular risk than previously thought."
"Social smoking is still a major cardiovascular health risk," Gawlik said. "No amount of smoking is safe."
According to a report in the American Journal of Health Promotion, social smoking is most common among adults 40 and under.
Michael Cummings, co-leader of the tobacco research program at the Medical University of South Carolina in Charleston, said, "Every cigarette you smoke does your body damage." Cummings, who was not involved in the study, made reference to social smoking, occasional smoking, light smoking, intermittent smoking, and nondaily smoking.
"For someone predisposed to cardiac disease for whatever reason, exposure to cigarette smoke stresses the heart and increases the risk of serious cardiac problems," Cummings said.
"Any smoking is bad," said Dr. Stanton Glantz, director of the Center for Tobacco Control Research and Education at the University of California, San Francisco, who was not involved in the study.
"The good news is that, unless the smoking has caused a heart attack, the effects go away when you stop," he said.