Another speaker at the conference, Neal Benowitz, of the University of California, San Francisco, presented work that addressed why Chinese have a lower rate of lung cancer than whites. Chinese tend to smoke fewer cigarettes than whites, and Benowitz found that they also metabolize nicotine more slowly. He is currently investigating whether this is due to a mutant CYP2A6 gene. The CYP2A6 seems to be an evolutionary remnant that still survives in our genome today. People completely lacking the gene do not seem to experience side effects of any kind.
Sellers suggests that perhaps the gene helped get rid of plant toxins early in evolution.
Both Benowitz s group and the team at University of Toronto are now looking at CYP2A6 genes in different ethnic groups to determine if some are more at risk for nicotine addiction.