Menthol cigarettes pose a greater health risk to the public than unflavored… (Joe Raedle, Getty Images )
The Food and Drug Administration has set the stage to restrict — or possibly ban — mentholated cigarettes on the grounds that they are more appealing to new smokers, more addictive to longtime smokers and pose a greater threat to the public's health than does unflavored tobacco.
In releasing a comprehensive review of research on menthol's effects as a tobacco additive Tuesday, the agency conceded that adding peppermint oil extract to cigarettes probably doesn't make them more likely to cause diseases such as lung cancer and emphysema. But its 153-page report concluded that menthol in tobacco was linked to "altered physiological responses to tobacco smoke." Those, in turn, may contribute to tobacco's highly addictive qualities and drive up disease by sustaining smoking behavior.
Release of the report opens a 60-day public comment period that could set the groundwork for new tobacco restrictions.
"FDA's actions today on menthol reflect our commitment to explore all potential options, including the establishment of product standards," said Mitch Zeller, director of the FDA's Center for Tobacco Products.
The agency acknowledged that the weight of any changes it may order would disproportionately affect minority communities. Mentholated cigarettes are the choice of nearly 75% of African American smokers and roughly 30% of Latino smokers. By contrast, just over 20% of non-Latino whites smoke menthol cigarettes.
The FDA said it would sponsor three new studies of menthol as a tobacco additive, one of which would explore whether genetic differences in taste perception may explain the striking patterns of mentholated cigarette use.
Since it was given additional regulatory powers over tobacco in 2009, the FDA has banned a number of additives that make tobacco more appealing to young smokers, including cloves, chocolate and fruit flavors.
But it has shown more reluctance to ban menthol, in part because its deliberations have touched off a furor in the African American community. In 2010, three major African American interest groups, including the National Black Chamber of Commerce, urged the FDA not to ban menthol as a cigarette additive. They cited concerns that such a move could create an underground market for mentholated cigarettes and stress law enforcement agencies.
The new research agenda may help untangle the web of factors that has made menthol cigarettes a mainstay of African American smokers. The FDA's research review acknowledged that heavy marketing of menthol cigarettes aimed at this group had contributed to that pattern of preference. But scientists are turning more attention to the physiological differences that might make certain groups more vulnerable to the allure of menthol-laced tobacco.
Some research has suggested that a genetic variant more common in African Americans may set in motion a variety of metabolic responses to nicotine that could steer a smoker toward mentholated cigarettes. Other studies have shown that whatever their age, gender or ethnicity, those who smoke menthols light up their first cigarette sooner after waking in the morning, are more likely to awaken at night for a smoke, are less successful in quitting and are more likely to relapse after quitting than smokers of regular cigarettes.
Two studies published Tuesday added to the mounting suspicion that adding menthol to tobacco causes it to behave differently in the human body. In one, a multinational team of neuroscientists showed that menthol acts on the same receptors in the human brain as nicotine, the principal addictive substance in tobacco. As a result, menthol appears to dampen the brain's normal response to nicotine, perhaps prompting smokers to compensate by taking in more. The findings were published in the journal PLOS One.
"Today I cannot tell you that menthol cigarettes are more addictive," said Nadine I. Kabbani of George Mason University in Virginia, one of the paper's senior authors. "But I can tell you that they're increasingly found to have biological and biophysical properties that go beyond flavor."
There are many ways in which menthol might tighten tobacco's grip on a smoker. In a review article published in the journal Frontiers in Pharmacology, Kabbani focused on menthol's effects on the acetylcholine nicotinic receptors found throughout the body, including in the brain.
Those receptors also respond to nicotine itself: They dilate smokers' blood vessels and make their skin warmer, they multiply as a person takes up a smoking habit, they increase attention and improve memory. But researchers are finding that menthol upends many of those well-documented effects of nicotine — sometimes exaggerating them, sometimes blunting them.
As a result, scientists are growing more certain that menthol is a biological force to be reckoned with.
"It's almost like spiking your vodka with beer," with equally unpredictable results, she said.