Adolescent Smokers Who Cut Back on Smoking Do Not Necessarily Reduce Exposure to Cancer-Causing Chemicals

MINNEAPOLIS / ST. PAUL (May 7, 2008) -- Adolescent smokers who reduce their cigarette smoking are still inhaling considerable amounts of cancer-causing chemicals, and their ultimate goal should be to quit completely, according to a tobacco research study conducted by the Masonic Cancer Center, University of Minnesota. The results are published in the May issue of Drug and Alcohol Dependence journal.

This study focused on finding out whether adolescents who are not interested in quitting could reduce their cigarette smoking, and whether that reduction corresponded to a decrease in exposure to chemicals found in cigarettes. Volunteer participants included 103 adolescents aged 13-19 years who were students at 14 Minneapolis/St. Paul area high schools between 2002-2004. 

“We found that even those adolescents who cut their daily cigarette smoking in half did not correspondingly decrease their exposure to carbon monoxide and cotinine, chemicals found in cigarettes,” said Karen Hanson, Ph.D., lead researcher on the study.  Hanson is with the Tobacco Use Research Center, a program of the Masonic Cancer Center, University of Minnesota.

“Furthermore, we found that after completion of the study, many of the participants resumed their former levels of smoking,” Hanson said. “This may be a reflection of peer pressure, and of the need for smoking cessation and support programs that address the specific issues faced by adolescent smokers so that they are able to quit.”

According to the last youth tobacco survey by the Minnesota Department of Health, the estimated number of students in grades 6 through 12 in Minnesota who are current tobacco users was about 96,600 in 2005.

Before entering this study, each participant on average smoked about 12 cigarettes per day. The participants had their first cigarette at about age 11.5 and became daily smokers at age 13.  Most of the participants preferred cigarette brands high in tar and nicotine.  Three of their closest friends also smoked, half of the participants used alcohol, most used caffeine, and many had previously undergone psychiatric or alcohol/drug treatment.

The study involved four treatment visits with cognitive-behavioral therapy over four weeks, and follow-up visits at three and six months. In addition, the participants, an almost equal ratio of mostly Caucasian males and females, were randomly assigned into three treatment groups to receive either a nicotine patch, nicotine gum, or a placebo.

The results: 94 adolescents (91.3 percent) completed the four-week treatment phase and 41 of them had reduced the number of cigarettes smoked each day by at least 50 percent. Cotinine levels did not decrease significantly at either the end of the treatment phase or at the follow-up visits. The researchers also noted that there were no important differences in outcomes between the three treatment groups.

“These results suggest that reduction of smoking may be a way to engage adolescents who are unable or unwilling to quit, but quitting, not reduction, should be the end goal,” Hanson said. “It further shows that smoking even a relatively few cigarettes a day is potentially harmful.”

Working with Hanson on this study were Emily Zylla, Sharon Allen, Zhongze Li, and senior author Dorothy Hatsukami, all with the Tobacco Use Research Center of the Masonic Cancer Center, University of Minnesota. The study was sponsored with a grant from the National Institute on Drug Abuse, part of the National Institutes of Health.

The Masonic Cancer Center, University of Minnesota, is part of the University’s Academic Health Center. It is a Comprehensive Cancer Center designated by the National Cancer Institute. The Tobacco Use Research Center is one of seven university-based programs in the United States funded by the National Institutes of Health. For more information, call the information line at 612-624-2620 or visit www.cancer.umn.edu.

Contact: Mary Lawson, Masonic Cancer Center, 612-624-6165
Sara Buss, Academic Health Center, 612-626-7037