Independent study at VCU finds lower levels of one carcinogen in new cigarette

By Lorraine Cichowski and Thomas Eissenberg

RICHMOND, Va. – A team of researchers at Virginia Commonwealth University has found sharply reduced levels of the cancer-causing chemicals, nitrosamines, during its independent testing of the Advance cigarette, suggesting some progress by the tobacco industry in its efforts to make less-harmful cigarettes.

Smokers who participated in a unique, three-week outpatient study at VCU's Clinical Behavioral Pharmacology Laboratory were found to have levels of nitrosamine metabolites in their urine that were 51 percent lower by their fifth day of smoking Advance cigarettes than levels registered when they smoked their own light or ultra-light brand of cigarette.  Not smoking at all resulted in 70 percent lower levels of nitrosamines, which are considered one of the most-potent, cancer-causing toxins in cigarette smoke, linked to lung cancer.

"Not smoking is the only proven method to decrease exposure to tobacco-related carcinogens and the likelihood of tobacco-related disease and death," says Thomas Eissenberg, Ph.D., VCU associate professor of psychology and head of the Clinical Behavioral Pharmacology Laboratory. "However, most smokers find it difficult to quit because they are dependent upon cigarette-delivered nicotine.

"If you continue to smoke, and you�re worried about nitrosamines, our data suggest that Advance reduces nitrosamine exposure significantly. We don�t know whether this reduced exposure to nitrosamines will actually decrease cancer risk from smoking. But, to the extent that nitrosamines are associated with tobacco-related mortality, incorporating low-nitrosamine tobacco in other products may be an important public health goal."

The study, which appears in the September issue of the journal Tobacco Control (www.tobaccocontrol.com), included 12 smokers between the ages of 18 and 50 who regularly smoke at least 15 king-sized, non-mentholated, light or ultra-light cigarettes daily. Smokers completed three, five-day sessions in which they smoked their own brand of cigarette, the Advance cigarette or no cigarettes at all, as assigned for the different periods by the researchers. As part of the research team's efforts to monitor compliance with the test conditions, urine samples were collected, breathe tests conducted and measurements taken on heart rate, carbon monoxide and nicotine inhalation, ability to control cigarette cravings and nitrosamine metabolite levels.

An important goal of the clinical study was to compare nitrosamine metabolite concentration in smokers' urine under the three conditions: smoking one's own brand, smoking Advance and not smoking at all.  The VCU study is the first by an independent team of researchers to measure the carcinogenic effects of so-called "potential reduced-exposure products" such as the Advance cigarette, which has been test marketed by Brown & Williamson Tobacco Corp. and Star Scientific, Inc., and is based on tobacco-curing technology developed by Star Scientific to reduce levels of nitrosamines.

In addition to measuring nitrosamine exposure, the study also sought to further previously published findings from Eissenberg's lab on levels of other chemicals produced by Advance smoke, particularly carbon monoxide and nicotine. A previous study found that, when compared with conventional cigarettes, Advance produced less carbon monoxide, which is linked to several smoking-related diseases, including heart disease. The earlier study also found, however, that Advance also delivered 25 percent more nicotine during a puff-for-puff comparison with conventional cigarettes.

Nicotine is the drug in tobacco that causes addiction, so higher levels of nicotine could lead to increased dependence on cigarettes.

The latest testing, which permitted smokers to take as many puffs as they wanted from Advance and their own cigarettes, revealed an interesting result.  Smokers took almost two fewer puffs, on average, from Advance than their own cigarette.  Urine tests taken from smokers in the current study revealed that Advance and conventional brands appeared to deliver similar amounts of nicotine.

"This difference in smoking behavior may explain the apparent discrepancy regarding nicotine intake in these two studies," Eissenberg said. "But this was only a five-day study.  Unfortunately, we don't know what will happen after a year. Will people start taking more puffs, increasing their nicotine exposure?"

Preliminary results were presented in February at the Ninth Annual Meeting of the Society for Research on Nicotine and Tobacco.

VCU is on the cutting edge of research into new smoking products being developed in an apparent attempt to help reduce the health hazards of smoking. Currently, little objective research beyond VCU's work exists to test claims by the tobacco industry that its new products may reduce smokers' exposure to certain elements of toxic smoke.  According to the Centers for Disease Control, more than 4,000 chemical compounds have been identified in tobacco smoke.  Of those, 43 are known to cause cancer.

The studies are supported by grants from the National Institute on Drug Abuse and VCU's Massey Cancer Center.