A U.S. advisory panel began weighing the effects of menthol flavoring in cigarettes on Tuesday as part of the government's new powers over the tobacco industry.

Smoked by about 19 million Americans, minty menthol cigarettes are under attack from health advocates who say the taste can be more enticing and possibly addicting than regular cigarettes.

At the start of a two-day public meeting, a committee of outside experts that advises the Food and Drug Administration began hearing evidence of menthol's impact on smokers' use and health. The panel is due to issue a report by March 2011.

The FDA could eventually ban or phase out menthol cigarettes, although some anti-smoking advocates and industry analysts are skeptical that will happen.

"Clearly the issues won't all be easy," FDA Commissioner Margaret Hamburg told the panel, which also will tackle the use of dissolvable tobacco products, among other issues, at future meetings.

Any government action against menthol could be a blow to Lorillard, the nation's third-largest cigarette company and maker of top-selling menthol brand Newport.

The 2009 law that gave the FDA oversight of tobacco products banned other cigarette flavors such as chocolate, clove and fruit that could entice children. But Congress exempted menthol, the most popular flavoring with about 27 percent of the cigarette market, and instead called for an FDA review.

The law was opposed by tobacco companies except the nation's largest cigarette maker, Altria Group Inc's Philip Morris unit. Philip Morris sells menthol versions of its Marlboro brand, while Reynolds American markets menthol-flavored Camels.

Officials from the manufacturers were expected to speak to the panel on Wednesday.

Lorillard, in a statement issued ahead of the meeting, said there was no evidence menthol cigarettes were more addictive or harmful than others.

"The science is clear and compelling that there is no differing health risk between menthol and non-menthol products," Lorillard Senior Vice President Bill True said.

Credit Suisse in January downgraded the U.S. tobacco sector to "market weight" from "overweight," citing concerns about the growing threat of regulations.

The FDA advisory committee is a 12-member panel that includes three nonvoting industry representatives. A second panel meeting is set for summer and will include an analysis of industry documents.