When thinking about a smoking addiction, everyone focuses on nicotine, but what about additives in cigarettes — could they be contributing to habit-forming behavior? A new Harvard study takes a close look at pyrazines, a staple ingredient in both “light” cigarettes, such as Marlboro Lights (Gold), and e-cigarettes as well. Pyrazine additives may be reinforcing the addictive qualities of nicotine, say the researchers who further recommend strict regulation of this particular cigarette (and e-cig) ingredient.
Just under 600 additives are approved for use in cigarettes. In particular, pyrazines are said to characterize the flavor and aroma of tobacco smoke, contributing what industry execs refer to as the brown notes and in some cases, cocoa, nutty, and popcorn type flavors. While each manufacturer has its own (undisclosed) recipe, e-cigarettes are said to include some of the same additives approved for regular cigarettes (though less of them), with additional flavorings to jazz up the taste of the vapor.
A concern of many scientists is that, while a flavoring may be safe to eat, the effects on the body could be vastly different when burned and inhaled. For this and other reasons, the Food and Drug Administration has warned the public of the health risks posed by vaping, which is legal for adults, though banned for minors in most states.
Meanwhile, consumers continue to vape, believing their new e-cigarettes are less risky and less addictive than regular cigarettes.
The process of nicotine dependence is complex, and scientists say it mainly results from how nicotine prompts the release of dopamine — a neurochemical involved in pleasure, arousal, and mood change — in the brain. Yet, past research suggests nicotine is not solely responsible for the addictive quality of cigarettes. What is the truth?
For the current study, the researchers explored how the use of pyrazines might enhance abuse potential. So they began by reviewing scientific research on the composition and role of cigarette additives while also examining internal tobacco industry documents made available as a result of litigation.
The tobacco industry, the researchers discovered, wanted to address declining sales in the wake of many scientific reports saying smoking is bad for your health. Unfortunately, the original low tar versions they created lacked the taste, aroma, and flavor of regular cigarettes... until the day they stumbled upon a winning combination of aromatic chemicals and substances in the successful MERIT brand, one of the first light cigarettes.
The ingredients of MERIT included five key additives, three of which were pyrazines. Along with contributing to aroma and flavor, pyrazines act on sensory receptors. It was this quality the industry found to be most helpful in curbing the harshness and irritating effects of nicotine and other ingredients. What industry scientists also understood about pyrazines is they have sensory and pharmacological effects which act independently of, and in tandem with, nicotine.
Specifically, pyrazine stimulation of receptors in the lining of the nose may enhance learned behavior, when acting either alone or in combination with other sensory stimuli (nicotine).
“Taken together, pyrazines appear to increase product appeal and make it easier for non-smokers to initiate smoking, more difficult for current smokers to quit, much easier for former smokers to relapse into smoking, and may mask the risks of both active and passive smoking,” concluded the researchers.
As a result of this research, they call on government agencies to regulate pyrazines and similar ingredients in cigarettes and e-cigarettes. Vaping may appear to be less damaging to your health than smoking; still, the chemical involved suggests it is far from safe.
Source: Alpert HR, Agaku IT, Connolly GN. A study of pyrazines in cigarettes and how additives might be used to enhance tobacco addiction. Tobacco Control. 2015.