Tobacco companies used American Indian imagery and stereotypes for decades to sell cigarettes to the nation’s white majority. Now Minnesota researchers hope that awareness of this insensitive marketing will motivate American Indians to quit smoking.

Ads featuring real or fictitious Indian icons, such as traditional headdresses and pipes, and offensive references such as “dumb injun,” were common in the first half of the 20th century, according to researchers with ClearWay Minnesota, a quit-smoking program funded by the state’s landmark 1998 legal settlement with tobacco companies. Later, the tone of the ads shifted, and some manufacturers used Indian imagery to suggest that their cigarettes were more natural and that smoking them was a spiritual experience.

“The tobacco industry … commodified a culture and people deeply connected to traditional tobacco, but also disproportionately impacted by the harms of commercial tobacco use,” the researchers wrote in a study published in the British journal Tobacco Control.

More than 38 percent of American Indian adults in Minnesota smoke cigarettes, according to 2015 survey data from the state Department of Health. That’s more than double the state’s overall rate, 16.2 percent. A higher share of Indians also smoke cigarettes containing menthol, which increases the difficulty of quitting, studies have suggested.

Tribal leaders in Minnesota are seeking to curb smoking of commercial nicotine-containing products by increasing awareness among their members about growing tobacco and using it for spiritual and ceremonial purposes only.

Research showing how companies misused native symbols and imagery is important to that effort, said Coco Villaluz, one of the study co-authors. If Indian smokers learn how companies “muddied the distinction” between traditional tobacco and commercial cigarettes, she said, that might give them extra incentive to quit recreational smoking.

The research was based on an analysis of 76 cigarette ads or internal marketing documents from the “Truth Tobacco” archive at the University of California, San Francisco.

One 1949 ad for Old Gold cigarettes included the phrase, “no heap big medicine talk.” In the 1980s, documents show, Sante Fe Natural Tobacco Company took the lead in using Indian symbols to suggest that its products were safer and more natural than other cigarettes.

Villaluz said ClearWay is creating a quit-smoking hotline that is specific to American Indians and is staffed by people who understand the differences between recreational smoking and cultural and religious use.