Study finds smoking marijuana and cocaine
can cause cancer
WASHINGTON (CNN)-- In the first study of
its kind, researchers found that smokers
of marijuana and crack cocaine show the
same kinds of precancerous conditions
caused by smoking tobacco.
The findings were released Tuesday in the
Journal of the National Cancer Institute.
In the study, researchers examined samples
of respiratory tract tissue from
participants who ranged in age from 21 to
50. To be eligible, the participants had
to be in one or more of the following
categories: Marijuana smokers who smoked
an average of 10 or more marijuana
cigarettes a week for the last five years
or longer; crack cocaine smokers who
smoked one gram or more of crack cocaine a
week for nine months or longer within the
past year; or tobacco smokers who smoked
20 cigarettes or more a day for the last
five years.
The researchers looked at genetic markers
known to be associated with increased risk
of lung cancer. Changes or overproduction
of some markers were found in a majority
of the study participants.
The findings suggested that tobacco was
not the only smoked substance that set the
changes preceding lung cancer development
in motion.
The study also showed that habitual
smoking of tobacco, marijuana or crack
cocaine in combination could potentially
lead to more cancerous alterations in the
molecular makeup of cellular structure
than single-smoking alone.
Dr. Sanford Barsky, co-author of the study
and a member of the University of
California, Los Angeles' Jonnson
Comprehensive Cancer Center, said he was
not surprised by the findings. He said any
substance that is inhaled, regardless of
chemical makeup, releases carcinogens into
the lungs and throat.
In an editorial accompanying the study, Dr
Li Mao and Dr. Yun Oh at the University of
Texas's M.D. Anderson Cancer Center
conclude that the nationwide teen
anti-tobacco effort might have an
"unintended consequence" -- teens will
substitute tobacco with marijuana.
They write while these anti-tobacco
campaigns are expected to reduce the
numbers of teenagers and children who
smoke tobacco cigarettes, the rate of
marijuana use is increasing.
They note the percentage of students
smoking marijuana on a daily basis has
risen from 1.9 percent in 1992 to 4.6
percent in 1995.
http://www.c
nn.com/HEALTH/9808/18/marijuana.cancer/
