US researchers warned on Wednesday that tobacco companies manipulate the amount of menthol in cigarettes to lure adolescents into smoking and to make that first impression about cigarettes not that irritable.

A study by researchers at Harvard School of public Health in the US concluded that there is a deliberate strategy to “recruit and addict young smokers,” by adjusting menthol levels in cigarettes. Therefore, the first-time smoker is left with a milder experience, as menthol masks the harshness and irritation of cigarettes.

The fresh taste of menthol manages, to a certain degree, to cover up the original cigarette smell and also ease the smoke inhalation, leaving the false impression that it might not be as unhealthy as the rest.

However, the level of nicotine remains the same, creating addiction among those trying to smoke, according to the study published in the American Journal of Public Health.

A recent survey conducted by the American Legacy Foundation, found that 81 percent of teen African-American smokers use menthol cigarettes compared to the 32 percent of white teens and 45 percent of Hispanics.

Previous studies have shown that menthol smokers are less likely to quit than their non-menthol peers. A bill is currently pending in Congress seeking to ban menthol in cigarettes and other tobacco products. The bill would give the US Food and Drug Administration power to regulate menthol and other additives in cigarettes.

“The bill would end the marketing of tobacco products to children, force companies for the first time to disclose the ingredients in their products and allow the FDA to regulate all tobacco products, including menthol cigarettes, based on science,” John R. Seffrin, chief executive officer of the American Cancer Society, said in a news release.

The study was prompted by data revealing that menthol sales had not declined along with other segments of the tobacco industry. On contrary, sales of menthol cigarettes appear to have increased among certain parts of the population, Dr. Howard, Koh, , director of the division of public health practice at the Harvard School of Public Health and author of the study, said according to the New York Times. That’s why “we wanted to dig deeper and explore exactly the mechanism,” he added.

Menthol cigarettes currently make up about 28 percent of the $70 billion cigarette industry in America.

For the current study, Dr. Koh and colleagues studied internal company research on menthol use released as part of a large tobacco settlement. Also as part of the study, they reviewed population studied on smoking trends and conducted independent laboratory tests.

“Tobacco companies researched how controlling menthol levels could increase brand sales among specific groups. They discovered that products with higher menthol levels and stronger perceived menthol sensations suited long-term smokers of menthol cigarettes, and milder brands with lower menthol levels appealed to younger smokers,” the study said.

Overall, the study found that 44 percent of smokers age 12 to 17 prefer menthol cigarettes. Therefore, the authors urge regulation of the tobacco industry and menthol, in particular.

Representatives of tobacco companies R.J. Reynolds, Philip Morris, and Lorillard dispute the findings. Lorillard Inc representative Michael Robinson sees the study as “a politically motivated lobbying tool,” Reuters reports.

David Howard, a spokesman for R.J. Reynolds, a unit of Reynolds American Inc and maker of Camel and Kool cigarettes said the study is not a scientific review of menthol cigarettes but “an efforts to push support for federal regulation of the tobacco industry.

David Sylvia, a spokesman for Philip Morris said there is no evidence supporting the conclusion of the study.

Smoking appears to be the biggest cause of preventable deaths in the US, killing more than 400,000 people annually. About 90 percent of cigarette customers become addicted on nicotine before age 19, according to the Center for Disease Control and Prevention. Ironic is the fact that most smokers become addicted before they’re legally old enough to buy a pack.

The American Legacy Foundation and the National Cancer Institute funded the Harvard study.