Smoking is more dangerous for black AmericansBMJ 1998; 317 doi: https://doi.org/10.1136/bmj.317.7151.98b (Published 11 July 1998) Cite this as: BMJ 1998;317:98
Black Americans who smoke are more likely to develop lung cancer and die from it than whites, even though they smoke fewer cigarettes a day.
Although black Americans are more likely to try to stop smoking than white Americans, they are less successful. The reasons are suggested by two articles and an editorial in JAMA--the journal of the American Medical Association (1998;280:135-9, 152-6, 179-80).
In a large epidemiological study of over 2000 smokers drawn from the third national health and nutrition examination survey, Dr Ralph Caraballo and colleagues from the Centers for Disease Control and Prevention in Atlanta found differences in serum cotinine concentrations among black, white, and Mexican American smokers. About 70-80% of the nicotine in the blood is converted to cotinine, which remains in the blood longer than nicotine.
Black smokers had higher serum concentrations of cotinine than white or Mexican Americans, even after adjustment for the number of cigarettes smoked, age, sex, weight, number of smokers at home, and hours exposed to smoke at work. Why?
“Blacks smoke more intensively than whites. They get about 30% more nicotine from a cigarette than whites do. That may account for their higher rate of lung cancer,” said Dr Neal Benowitz, professor of medicine at the University of California in San Francisco, and one of the authors of the second of the studies. This study showed that total and non-renal clearance rates for cotinine were 25-30% slower in black smokers than white.
“The conversion of nicotine to cotinine is the same in blacks and whites, but the clearance is slower in African Americans. That will be important if there is a connection between high cotinine levels and addiction. High cotinine levels might also be a marker of exposure to carcinogens in tobacco smoke,” said Dr Caraballo.