STUDIES SHOW BLACKS MAY ABSORB MORE NICOTINE

Blacks who smoke absorb more nicotine than white or Hispanic smokers, a
difference that explains why blacks tend to suffer more from
tobacco-related disease and have more trouble kicking the habit,
researchers reported yesterday.

The new data emerges from two studies in today's edition of the Journal of
the American Medical Association that constitute the broadest effort ever
to understand racial differences in smoking.

"It's really important research," said Jack Henningfield, an expert on
nicotine addiction at Johns Hopkins University. "It raises a whole bunch of
serious questions that need to be answered" about the biology of smoking
and proper cessation treatment. "The bad news is, it's 1998 and we're just
finding this out."

African American adults historically have smoked at higher rates than the
general population, but in recent years they have smoked at about the same
rates as other groups. More than 31 percent of black men smoke, compared to
nearly 28 percent of white men; 22.7 percent of black women smoke, compared
to 24.4 percent of white women. Since 1976, smoking rates among black
teenagers declined dramatically, but in recent years the rate has begun to
climb again.

The two new studies focus on bloodstream levels of cotinine, the most
common chemical produced by the body from nicotine.

In the first study, researchers at the federal Centers For Disease Control
and Prevention in Atlanta measured the amount of cotinine in the blood of
7,182 subjects, 2,136 of whom said they had smoked in the previous five
days.

"For each level of cigarette smoking, the levels for African Americans were
substantially higher," said lead author Ralph Caraballo of the CDC. Black
participants in the study had cotinine levels in their blood that were
between 12 percent and 50 percent higher than those of white subjects, and
32 percent to 56 percent higher than Mexican Americans.

The researchers called the results "intriguing" because, they wrote,
cessation experts say blacks "are more likely to try to quit but have a
lower success rate than white smokers." The higher levels of cotinine
suggest that blacks absorb more nicotine from cigarettes than whites.

The researchers compensated for the fact that blacks tend to smoke fewer
cigarettes than whites, though Caraballo said that they could not take into
account possible behavioral differences in the ways that people of
different races smoke. Previous studies have shown that black smokers tend
to take more smoke into their lungs or hold it in the lungs for a longer
time. Caraballo noted that such studies have tried to account for the
greater popularity of menthol cigarettes among blacks, and the possibility
that the anesthetizing effect of menthol "could allow you to smoke more
deeply." But he said the structure of his study made such inquiries
impossible.

The second study found that blacks also keep cotinine in their bodies
longer than whites. Keeping nicotine in the body longer could enhance
smoking's pleasurable effects. Researchers at the University of California
in San Francisco studied 79 smokers and found that an African American who
smoked 12 to 15 cigarettes a day gets as much nicotine as whites who smoke
a full pack of 20 cigarettes a day - a difference that Henningfield calls
"small but real," with important implications for those who would help
African Americans quit smoking. That study solved the issue of behavioral
differences by infusing cotinine directly into the bloodstreams of the test
subjects.

Checked-by: (Joel W. Johnson)