THE CASE AGAINST LEGALIZING MARIJUANA

This guest column was written by Susan Urbanek Linville, a science writer
for the Wonderpage.

Several letters have been published in the past few weeks touting the
safety and benefits of marijuana use. The authors' implied that definitive
scientific evidence exists to support their claims and no additional
research is needed to evaluate the impact and long-term effects of
marijuana use. Is this truly the case?

Since 1970, more than 10,000 marijuana studies have been conducted. Some
were mainly anecdotal, some fell short of the scientific rigor needed to
make conclusions, and others were performed under acceptable scientific
standards. It can be difficult for a layperson to evaluate this mass of
data, but two recent publications should prove helpful: "Marijuana: What
are the Risks? A Review of the Research Literature for Prevention
Practice," Prevention Research Institute, Lexington, Ky., and "Marijuana
and Medicine: Assessing the Science Base," Institute of Medicine, National
Academy Press. This second article has been mentioned as a source
establishing the safety of marijuana. All unattributed quotes below are
from that source.

Is marijuana safe? Some argue that marijuana is a natural herb with a
history of medicinal use, but historic use does not equate safety. Foxglove
is a natural herb with a 1,000 year history, once used to treat epilepsy,
water retention and cardiac symptoms. But foxglove contains digitoxin, a
glycoside that can cause death.

While doses of marijuana are not fatal, long-term use may trigger secondary
problems such as cancer, heart attack and accidental death. Marijuana is a
plant product that contains more than 400 chemical compounds. When exposed
to heat, these compounds react, subjecting the smoker to some 2,000
chemicals including hydrogen cyanide, ammonia, carbon monoxide,
acetaldehyde, acetone and phenol as well as carcinogens found in tobacco
smoke: benzopyrene, benzoanthracene, benzene and nitrosamine. Benzopyrene,
in particular, has been implicated in lung cancer and is known to suppress
a gene (P53) that governs cell growth.

It is true that no study has definitively linked marijuana smoking to lung
cancer, but this is because a high percentage of marijuana smokers are also
tobacco smokers and it is difficult to untangle the two effects. It is
interesting to note that MAPS (Multidisciplinary Association for
Psychedelic Studies) and NORML (National Organization for the Reform of
Marijuana Laws) are sponsoring research to develop vaporizers to reduce the
amount of tar reaching the marijuana smoker's lungs. Their own literature
(the MAPS Bulletin, Summer 1966) states: "marijuana tars are rich in
carcinogenic compounds."

While marijuana use may not lead to sudden death in healthy individuals, a
typical dose increases heart rate by 20-50 percent and leads to sodium and
fluid retention, increasing the risk of heart attack, arrhythmia, chest
pain or congestive heart failure for individuals in poor health.

Like alcohol, marijuana impairs the central nervous system. "Cognitive
impairment associated with acutely administered marijuana limits the
activities that people would be able to do safely and productively. For
example, no one under the influence of marijuana or THC should drive a
vehicle or operate potentially dangerous equipment." The typical THC dose
results in a level of impairment just slightly less than an alcohol blood
level of 0.08 percent. If current patterns of alcohol use and drunk driving
are indicators of human behavior, legalized marijuana will lead to hundreds
of secondary deaths each year.

Proponents of legalizing marijuana often claim medicinal use of
cannabinoids as a primary justification. Marijuana, they claim, has been
used to reduce nausea, glaucoma, convulsions, spasms, asthma, pain, and
promote appetite. However, a closer look at the literature reveals some
interesting conclusions. As an anti-nausea drug, "cannabinoids are mildly
effective in preventing emesis," though they decrease in effectiveness over
time and side effects (intoxication and impairment) are not well tolerated.
Marijuana does decrease inner eye pressure, the cause of glaucoma, in
normal individuals. "However, the effect is too short lived and requires
too high doses and there are too many side effects to recommend lifelong
use in the treatment of glaucoma." As an anti-convulsant, marijuana can
both reduce and cause convulsions. Clinical studies with Parkinson's, MS
and Huntington's patients, have shown little symptom abatement.

Prenatal marijuana use is associated with lower IQ, behavioral, attention
and memory problems in offspring. Fortunately, most children recover after
about age 6. Should they have to?

Marijuana use has been linked to low white blood cell counts. "A major
concern with marijuana smoking in HIV-infected patients is that they might
be more vulnerable than other marijuana users to immunosuppressive effects
of marijuana or to the exposure of infectious organisms associated with
marijuana plant material." Marijuana use has also been found to cause
psychotic events in prone individuals and precipitate schizophrenic episodes.

Marijuana is no wonder drug. Like other recreational drugs, it has a
variety of associated risks including increased risk of death due to
cancer, heart disease and accident. As a drug for the treatment of disease,
it is mediocre at best. It would be a refreshing change if proponents for
legalizing marijuana would quit hiding behind the "safe drug" and "great
medicine" rhetoric and admit the obvious. They want to get high without the
fear of being thrown into jail.