However, with formerly secret internal documents known as the "Tobacco Papers," dated between 1960 and 2010 from the seven major tobacco companies operating in the United States, researchers at the University of California, San Francisco, revealed that cigarette makers had started investing in alternative forms of nicotine delivery as early as the 1950s, but stopped short because people largely regarded nicotine as harmful, and such products might have attracted the attention of FDA regulators. Published this week in the American Journal of Public Health (AJPH), the study titled "Tobacco Industry Research on Nicotine Replacement Therapy: 'If Anyone Is Going to Take Away Our Business It Should Be Us'" found that in 1987, three years after FDA first approved nicotine gum as a quitting aid, the tide had turned on the public perception of nicotine; and that by 1992, the tobacco industry had determined that patches and gum by themselves do not help smokers quit. For more than a decade, the companies did not act on this knowledge out of fear of FDA regulation. But once the federal agency started regulating cigarettes in 2009, they went all out in their bid to develop and sell NRT. The Tobacco Papers reveal that companies conjectured that their new nicotine products could successfully compete with pharmaceutical NRT and they set the goal of gaining market control of all products containing nicotine. "It was surprising to discover the industry came to view NRT as just another product," Dorie Apollonio, associate professor in clinical pharmacy and lead author of the study, was quoted as saying in a UCSF news release. "The tobacco companies want people to get nicotine - and they're open-minded about how they get it." Smoking is responsible for more than 480,000 deaths every year in the United States, according to the U.S. Centers for Disease Control and Prevention (CDC), and another 16 million Americans live with a smoking-related disease. The costs of such illnesses total more than 300 billion U.S.