Researchers find genetic vulnerability to menthol cigarette use

Friday, February 15, 2019

FDA- and NIH-funded study finds unexpected sensory variant exclusive to African-Americans

A genetic variant found only in people of African descent significantly increases a smoker’s preference for cigarettes containing menthol, a flavor additive. The variant of the MRGPRX4 gene is five to eight times more frequent among smokers who use menthol cigarettes than other smokers, according to an international group of researchers supported by the U.S. Food and Drug Administration and the National Institutes of Health. The multiethnic study is the first to look across all genes to identify genetic vulnerability to menthol cigarettes. The paper was published online in the journal PLOS Genetics on Feb. 15.

Menthol provides a minty taste and a cooling or soothing sensation, and plays a particularly troubling role in U.S. cigarette smoking patterns. According to the FDA, nearly 20 million people in the United States smoke menthol cigarettes, which are particularly popular among African-American smokers and teen smokers. In the U.S., 86 percent of African-American smokers use menthol cigarettes, compared to less than 30 percent of smokers of European descent. In addition, menthol cigarettes may be harder to quit than other cigarettes.

Although not originally the focus of the study, researchers also uncovered clues as to how menthol may reduce the irritation and harshness of smoking cigarettes.

“This study sheds light on the molecular mechanisms of how menthol interacts with the body,” said Andrew Griffith, M.D., Ph.D., scientific director and acting deputy director of NIH’s National Institute on Deafness and Other Communications Disorders (NIDCD). “These results can help inform public health strategies to lower the rates of harmful cigarette smoking among groups particularly vulnerable to using menthol cigarettes.”

The research team, led by Dennis Drayna, Ph.D., chief of the Section on Genetics of Communication Disorders at the NIDCD, conducted detailed genetic analyses on 1,300 adults. In the initial analyses, researchers at the University of Texas Southwestern Medical Center, Dallas (UT Southwestern), used data from a multiethnic, population-based group of smokers from the Dallas Heart Study and from an African-American group of smokers from the Dallas Biobank. In conjunction with researchers from the Schroeder Institute® for Tobacco Research, Washington, D.C., the scientists further confirmed their findings in a group of African-American smokers enrolled in the Washington, D.C., Tobacco Quitline^TM.