Newsgroups: alt.hemp
From: Christopher Clay <cclay@icis.on.ca>
Subject: Marijuana Safer than Tobacco - Medical Post, Sept./94
Message-ID: <DAqnxA.Awz@icis.on.ca>
Date: Sun, 25 Jun 1995 17:15:10 GMT
Marijuana Less Harmful to Lungs than Cigarettes
L'ESTEREL, Quebec -- Heavy marijuana smokers show less evidence
That's according to the principal investigator of a study done at
Speaking at the third annual meeting of the International
"My own feeling is that marijuana smokers probably will not
"It may be that the THC (delta-9-tetrahydrocannabinol) in
His study, which aimed to measure the pulmonary effects of
Marijuana users in the study smoked three or four joints daily
"There is a seven-fold difference in the amount of smoke to which
"It's the quantitative difference in smoke exposure that might
Moreover, the phagocytes gathered from the lungs of marijuana
"We have previously shown that the macrophages that are harvested
Dr. Tashkin measured the clearance of the molecule diethylene
If DTPA clearance is accelerated, then it implies an increase in
Dr. Tashkin noted DTPA clearance is accelerated in tobacco smoke-
Initially, the chronic effects of marijuana smoke were measured
To determine the acute effects of marijuana and tobacco smoking,
"What we found was the clearance of DTPA was abnormally rapid
As with the lungs to tobacco smokers, when the lungs of marijuana
But whereas tobacco smoke has a concomitant effect of activating
"It may be that the macrophages from marijuana smokers release
Medical Post, Sept. 6 1994
of lung injury than heavy tobacco smokers, and it may be
cannabinoids that are protecting them from developing a condition
like emphysema.
the University of California at Los Angeles (UCLA).
Cannabis Research Society here, Dr. Donald Tashkin, a
pulmonologist and UCLA professor of medicine, concluded heavy
marijuana use did not cause the same degree of lung injury as
tobacco smoke.
develop emphysema as a consequence of smoking marijuana," he
said, but cautioned that does not rule out the development of
other conditions like respiratory carcinoma.
marijuana could have different effects on inflammatory cells,
which may mediate injury in the lung."
habitual marijuana use, followed nine tobacco smokers, 10
marijuana smokers, 10 nonsmokers and four smokers of both
marijuana and tobacco. He gave both quantitative and qualitative
explanations for his finding.
for 15 years on average, while tobacco smokers in the study
smoked 25 cigarettes daily over a period of 20 years, indicating
a marked difference in exposure to smoke.
marijuana and tobacco smokers are exposed," he said.
explain the difference in the degree of lung injury as assessed
by these physiologic indices."
smokers do not have the same properties as those gathered from
the lungs of tobacco smokers.
from the rinse-out of the lungs of marijuana smokers seem not to
be activated," he said. "They do not release toxic oxygen
species, either under basal conditions or under stimulated
conditions nearly to the extent that tobacco macrophages do. If
anything, basal secretion of superoxide seems to be reduced in
the marijuana smokers."
triamine penta-acetate (DTPA) from the lung, believed to be a
more sensitive indicator of lung injury than measuring the lung's
diffusing capacity.
the leakiness of the alveolar epithelial membrane, which implies
injury to the membrane, he said.
related lung injury.
in comparison to those of tobacco smoke: DTPA clearance was
measured at about 12 hours after the last marijuana or tobacco
cigarette smoked.
Dr. Tashkin restudied these smokers a week or two later, giving
them a single joint of marijuana or a single tobacco cigarette or
both, and then measuring DTPA clearance 15 minutes subsequently.
from the lung in the tobacco smokers," he said. "It was about
twice the rate of non-smokers. In the marijuana smokers, there
was a tendency toward a much less rapid rate of clearance. There
was no acute effect in either tobacco or marijuana, and there was
no added effect of marijuana or tobacco."
smokers are "washed out", a marked increase in the number of
alveolar macrophages is witnessed.
the macrophages, leading to the subsequent release of certain
toxic substances, marijuana smoke fails to activate the
macrophages, Dr. Tashkin said. He noted this difference could be
attributed to differential regulation of cytokins.
certain suppressive cytokins, like transforming growth factor-
beta, which is known to suppress the inflammatory activity of
nearly all of the site populations," he said. "That's our
hypothesis, which we are currently exploring."