Researchers scoured more than 7 million tobacco industry documents to see how additives known as pyrazines were being used and found these ingredients were introduced after consumers in the 1960s rejected the first “low-tar” cigarettes as being flavorless.
While nicotine, a stimulant in tobacco, has long been known to be addictive, the study offers fresh evidence that tobacco companies may have added pyrazines to cigarettes to support this addiction, said Dr. Maciej Goniewicz, a researcher at Roswell Park Cancer Institute in Buffalo, New York.
“They may facilitate delivery of nicotine to the brain, thus smokers may experience stronger effects of nicotine or these effects may happen faster,” Goniewicz, who wasn’t involved in the study, said by email.
Pyrazines may also stimulate pleasant senses of smell, taste or vision, he added. “Smokers associate these pleasant experiences with their cigarettes and this may lead to developing a stronger dependence on cigarettes.”
Smoking is the leading cause of avoidable deaths, according to the U.S. Centers for Disease Control and Prevention. Smoking dramatically increases the risk of coronary heart disease, stroke, and lung cancer. It can also contribute to cancers almost anywhere in the body, according to the CDC.
Cigarette manufacturers started heavily marketing “light” and “low tar” cigarettes after a landmark 1964 Surgeon General’s report warned of the health risks of smoking. Companies often described these options as safer than regular or “full-flavor” cigarettes, according to the CDC.
But there is no risk-free level of exposure to tobacco smoke, or any safe cigarette, the CDC says. In the U.S., terms like “light,” “low,” and “mild” can no longer be used to promote cigarettes.
For their study, published in Tobacco Control, Dr. Hillel Alpert and colleagues at the Harvard School of Public Health explored the history of additives like pyrazines and manufacturers’ knowledge of how these ingredients might act on the brain to make cigarettes more addictive.
They found documents showing cigarette manufacturers specifically added pyrazines to cigarettes to make them more appealing to consumers.
The industry documents also showed that companies had some evidence that pyrazines could trigger reactions in the brain that make people more likely to crave cigarettes and smoke more often.
Alpert didn’t respond to requests for comment on the study.
Irina Stepanov, a researcher in cancer and environmental health at the University of Minnesota in Minneapolis, told Reuters Health that smokers may not be able to avoid pyrazines because just about any commercially produced cigarette might contain them.
These additives can make cigarettes more flavorful and reduce the harshness of the smoke, causing people to inhale more deeply and receive more nicotine, Stepanov, who wasn’t involved in the study, said by email.
“That alone can contribute to the addictiveness of cigarettes,” she said.
Pyrazines may also help flood the brain with dopamine, a chemical involved in regulating sensations of pleasure, she added.
“The case of pyrazines adds support to previous findings that “low-tar” cigarettes are not safer than regular brands,” Stepanov said. “All cigarettes are addictive and harmful.”
In an unrelated study in the same journal, researchers found that raising the minimum age for buying cigarettes to 21 could discourage adolescents from smoking
The study compared smoking trends of more than 16,000 high school students in Needham, Massachusetts, the first town in the U.S. to raise the minimum tobacco sales age to 21 in 2005, and 16 surrounding communities. Between 2006 and 2010, smoking fell from 13 to 7 percent among the Needham students but only from 15 to 12 percent among kids in the surrounding communities.
“Most experts agree it’s a combination of strategies that will achieve the greatest impact . . . but our study shows increasing sales age to 21 can further decrease youth smoking,” lead author Shari Kessel Schneider of Education Development Center, Inc. in Waltham, Massachusetts told Reuters Health by phone.