Very few smokers know there is sugar added to cigarettes, a new survey suggests. In addition, very few realize that added sugar increases toxins in cigarette smoke, the study authors wrote in the journal Nicotine and Tobacco Research. "Knowledge is power and there is a clear gap in awareness," said lead researcher Andrew Seidenberg, a public health doctoral student at the University of North Carolina at Chapel Hill. Cigarettes contain natural and added sugars to reduce the harshness of smoke, making it easier to inhale. This also increases the amount of harmful chemicals in smoke and the addictive potential of smoking, Seidenberg said.

Seidenberg and colleagues surveyed 4,350 adult cigarette smokers by recruiting them through Amazon Mechanical Turk to participate in an online experiment on e-cigarette advertising. At the end of the experiment, survey takers answered two questions about added sugars in cigarettes: "Is sugar added to cigarettes?" and "Adding sugar to cigarettes increases toxins in cigarette smoke. Before this survey, had you ever heard of this effect of added sugar?"

Participants also had the option of providing open-ended comments at the end of the study. The researchers found that 5.5 percent of survey takers knew sugar was added to cigarettes. The proportion who knew this was never higher than 10 percent when respondents were grouped by characteristics like gender, age, income, education level, race and ethnicity. And only 3.8 percent of survey respondents knew added sugar increases toxins in smoke.