Smoking
Enhanced brain response to smoking cues found in African American
By University of Minnesota
Jun 3, 2006, 09:21

African American smokers show greater brain activations in response to smoking cues, such as images of individuals smoking, than Caucasian smokers, according to researchers at the University of Minnesota. The study, published in the June issue of the journal Addiction Biology, measured increased brain activity in regions associated with emotion and reward, which may explain why African American smokers are less successful than Caucasians at quitting.

Led by Kolawole Okuyemi, M.D., M.P.H., director of the Program on Health Disparities Research in the Medical School and associate professor in the Department of Family Medicine and Community Health, the study used functional magnetic resonance imaging (fMRI) to measure participants' brain activation while viewing images of African American and Caucasian models who were either smoking (smoking cues) or engaging in everyday activities (neutral cues). "We found that African American smokers showed greater brain activations in response to smoking cues, versus neutral cues, than Caucasian smokers in various parts of the brain," Okuyemi said. Most notably, Okuyemi added, there were significant differences in areas of the cortex, which have been correlated with emotion and reward.

These preliminary results may offer clues into why African Americans, although more likely to attempt to quit smoking than Caucasians, are less likely to succeed. "Cigarette craving is an important challenge that smokers face when trying to quit smoking, and those with more intense cravings are more likely to relapse back to smoking," Okuyemi said. Craving can be elicited through smoking-related cues, such as seeing others smoke, he added. "When presented with smoking cues, smokers demonstrate distinct evidence of physiological and behavior responses."

"This study further sheds light on possible reasons for lower success rates in smoking cessation in African Americans," said Jasjit S. Ahluwalia, M.D., M.P.H., co-author and executive director of Office of Clinical Research in the University's Academic Health Center. "These findings add to the body of knowledge about differences in African American smokers--notably that metabolism of nicotine tends to be slower in African American smokers than in other populations."

The study used fMRI to examine 17 smokers (8 African American, 9 Caucasian) after 12-hours of abstinence and 17 nonsmokers (8 African American, 9 Caucasian).

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