Biomedical News

Light vs. Regular Cigarettes: All Equally Bad!

Posted on Wednesday, March 09, 2005

A University of Minnesota Cancer Center study reports that light and ultra-light cigarettes are just as harmful as regular cigarettes, and marketing messages that imply otherwise are just plain misleading.

Scheduled for publication in the March 8 issue of Cancer Epidemiology, Biomarkers and Prevention journal, the study finds no significant differences in the amounts of nicotine and cancer-causing substances taken in by smokers of regular, light, and ultra-light cigarettes. The results suggest that there is no decreased risk for lung cancer in smokers of ultra-light and light cigarettes compared with smokers of regular cigarettes.

This study is the first to compare the uptake of lung carcinogens in smokers of light, ultra-light, and regular cigarettes. Newer and more sophisticated laboratory tests were used to look for remains of NNK and PAH, two well-known carcinogens in tobacco, in urine samples provided by the 175 smokers in the study.  Stephen Hecht, Ph.D., tobacco researcher with the University of Minnesota Cancer Center and Transdisciplinary Tobacco Use Research Center, led the research team on this study.

“The large market share for light and ultra-light cigarettes in the United States has not translated into a decrease in lung cancer incidences or deaths,” Hecht says. “Our findings provide an explanation for this and also reinforce conclusions from other studies that labels such as ‘light’ and ‘ultra-light’ are misleading because consumers interpret them to mean reduced health risk.”

He notes that the current method used by the Federal Trade Commission (FTC) to classify cigarettes is useless in determining the levels of toxins taken in and may be inadvertently contributing to the public misconception that light and ultra-light cigarettes are less harmful.

About 20 percent of adults in the United States smoke cigarettes. Currently, the FTC classifies cigarettes with greater than 14.5 mg tar as regular; between 6.5 – 14.4 mg tar as light; and 6.5. mg tar or less as ultra-light.

This study involved 175 smokers who completed a tobacco use questionnaire that included identifying their current brand as regular, light, or ultra-light. Each participant also was required to give a urine sample which the researchers used to measure two metabolites of a tobacco-specific lung cancer-causing substance: 4-(methylnitrosamino)-1-(3-pyridy1) 1-butanol (NNAL) and its glucuromides (NNAL-glucs). Also measured was 1-hydroxypyrene, a marker of uptake of carcinogenic polycyclic aromatic hydrocarbons (PAH).

According to Hecht, the presence of NNAL and NNAL-glucs in the urine indicates a potent cancer-causing toxin called NNK has been absorbed in the body. (NNK or 4-(methylnitrosamino) - 1-(3-pyridyl)-1 butanone has been found to cause cancer in laboratory mice and rats). In addition to these toxins, the researchers also measured the total amount of cotinine, an indicator of how much nicotine is taken in.

“We found no statistically significant differences in levels of those substances in smokers of regular, light, and ultra-light cigarettes,” says Hecht. “If there is no difference in toxin levels, then there is no difference in the harmful effects of the cigarettes.”

“Additionally, since there is no decrease in the amounts of toxins NNK and PAH in smokers of light and ultra-light cigarettes, we can deduce no decreased risk from lung cancer in smokers of light and ultra-light cigarettes compared with smokers of regular cigarettes,” he says.

Hecht says this study shows the importance of measuring uptake of cancer-causing substances in people who smoke newer brands of cigarettes touted as less harmful, instead of just listing the tar and nicotine levels.

“Evaluating newer brands by the FTC’s machine smoking method is essentially useless in determining carcinogen uptake,” he says. “If the biomarkers we used in our study had been available when light and ultra-light cigarettes were introduced, smokers may not have been as misled by cigarette manufacturers’ advertising and by the FTC machine values for tar and nicotine into thinking these cigarettes were less harmful.”