Sparked anew by Gov. Arnold Schwarzenegger's call for the state to study the legalization of marijuana, both sides in the smoldering pot debate point to research to bolster their positions.
Such recitation of conflicting marijuana studies can be manipulated and selected buffet-style to serve whatever political and health agenda is being touted.
Even governmental findings can be contradictory. In 1999, for instance, the Office of National Drug Control Policy asked the Institute of Medicine to review evidence. The institute found that, "except for the harms associated with smoking, the adverse effects of marijuana use are within the range of effects tolerated for other medications."
Yet in 2006, the Food and Drug Administration ruled that marijuana has no health benefits and has known and proven harms. It is classified a Schedule 1 drug — the highest risk of addiction — in the Controlled Substances Act.
Wading through the medical literature, though, makes those conclusions less cut and dried.
"When I was a resident in Kaiser in San Francisco in 1978, I gave a lecture to physicians on marijuana, and I remember my conclusion at that time was that you can find in the literature whatever you were looking for," says Dr. Donald Abrams, a University of California, San Francisco, oncologist and leading medical marijuana researcher. " 'Marijuana is good for asthma.' 'Marijuana's bad for asthma.' 'Marijuana causes schizophrenia.' 'Marijuana (decreases) schizophrenia.' And, you know, the evidence is still like that."
There are many factors, of course. As noted by UCLA pulmonologist Dr. Donald Tashkin, who has studied marijuana's effects on the lungs for three decades, "That's just the nature of medical science. You have to deal with variability. The population studied may be different or the methods used to study may differ."
Yet when the arguments for legalization of marijuana, both for medicinal and recreational use, are put forth, solid medical science often gets clouded in an ideological haze.
"Although we like to say we separate politics from science, with medical marijuana, that's really difficult," Abrams says. "It depends on who does the study, where it's published and what their agenda is."
Bearing in mind those caveats, here is a look at the research on marijuana's effect in areas critical to health.
Lungs
UCLA's Tashkin studied heavy marijuana smokers to determine whether the use led to increased risk of lung cancer and chronic obstructive pulmonary disease, or COPD. He had hypothesized that there would be a definitive link between cancer and marijuana smoking, yet the results proved otherwise.
"What we found instead was no association and even a suggestion of some protective effect," says Tashkin, whose research was the largest case-control study ever conducted. The study was funded by the National Institutes of Health.
Tobacco smokers in the study had as much as a 21-fold increase in lung cancer risk. Cigarette smokers, too, developed COPD more often in the study, and researchers found that marijuana did not impair lung function. Tashkin, supported by other research, concluded that the active ingredient tetrahydrocannabinol, or THC, has an "anti- tumoral effect" in which "cells die earlier before they age enough to develop mutations that might lead to lung cancer."
However, the smoke from marijuana did swell the airways and lead to a greater risk of chronic bronchitis.
"Early on, when our research appeared as if there would be a negative impact on lung health, I was opposed to legalization because I thought it would lead to increased use and that would lead to increased health effects," Tashkin says.
"But at this point, I'd be in favor of legalization. I wouldn't encourage anybody to smoke any substances, because of the potential for harm. But I don't think it should be stigmatized as an illegal substance.
"Tobacco smoking causes far more harm. And in terms of an intoxicant, alcohol causes far more harm."
News Hawk: MsRedEye: 420 MAGAZINE ® - Medical Marijuana Publication & Social Networking
Source: The Sacramento Bee
Author: Sam McManis
Copyright: 2009 The Sacramento Bee
Contact: Contact Us - sacbee.com
Website: Legalize it? Medical evidence on marijuana blows both ways - Sacramento Living - Sacramento Food and Wine, Home, Health | Sacramento Bee
Such recitation of conflicting marijuana studies can be manipulated and selected buffet-style to serve whatever political and health agenda is being touted.
Even governmental findings can be contradictory. In 1999, for instance, the Office of National Drug Control Policy asked the Institute of Medicine to review evidence. The institute found that, "except for the harms associated with smoking, the adverse effects of marijuana use are within the range of effects tolerated for other medications."
Yet in 2006, the Food and Drug Administration ruled that marijuana has no health benefits and has known and proven harms. It is classified a Schedule 1 drug — the highest risk of addiction — in the Controlled Substances Act.
Wading through the medical literature, though, makes those conclusions less cut and dried.
"When I was a resident in Kaiser in San Francisco in 1978, I gave a lecture to physicians on marijuana, and I remember my conclusion at that time was that you can find in the literature whatever you were looking for," says Dr. Donald Abrams, a University of California, San Francisco, oncologist and leading medical marijuana researcher. " 'Marijuana is good for asthma.' 'Marijuana's bad for asthma.' 'Marijuana causes schizophrenia.' 'Marijuana (decreases) schizophrenia.' And, you know, the evidence is still like that."
There are many factors, of course. As noted by UCLA pulmonologist Dr. Donald Tashkin, who has studied marijuana's effects on the lungs for three decades, "That's just the nature of medical science. You have to deal with variability. The population studied may be different or the methods used to study may differ."
Yet when the arguments for legalization of marijuana, both for medicinal and recreational use, are put forth, solid medical science often gets clouded in an ideological haze.
"Although we like to say we separate politics from science, with medical marijuana, that's really difficult," Abrams says. "It depends on who does the study, where it's published and what their agenda is."
Bearing in mind those caveats, here is a look at the research on marijuana's effect in areas critical to health.
Lungs
UCLA's Tashkin studied heavy marijuana smokers to determine whether the use led to increased risk of lung cancer and chronic obstructive pulmonary disease, or COPD. He had hypothesized that there would be a definitive link between cancer and marijuana smoking, yet the results proved otherwise.
"What we found instead was no association and even a suggestion of some protective effect," says Tashkin, whose research was the largest case-control study ever conducted. The study was funded by the National Institutes of Health.
Tobacco smokers in the study had as much as a 21-fold increase in lung cancer risk. Cigarette smokers, too, developed COPD more often in the study, and researchers found that marijuana did not impair lung function. Tashkin, supported by other research, concluded that the active ingredient tetrahydrocannabinol, or THC, has an "anti- tumoral effect" in which "cells die earlier before they age enough to develop mutations that might lead to lung cancer."
However, the smoke from marijuana did swell the airways and lead to a greater risk of chronic bronchitis.
"Early on, when our research appeared as if there would be a negative impact on lung health, I was opposed to legalization because I thought it would lead to increased use and that would lead to increased health effects," Tashkin says.
"But at this point, I'd be in favor of legalization. I wouldn't encourage anybody to smoke any substances, because of the potential for harm. But I don't think it should be stigmatized as an illegal substance.
"Tobacco smoking causes far more harm. And in terms of an intoxicant, alcohol causes far more harm."
News Hawk: MsRedEye: 420 MAGAZINE ® - Medical Marijuana Publication & Social Networking
Source: The Sacramento Bee
Author: Sam McManis
Copyright: 2009 The Sacramento Bee
Contact: Contact Us - sacbee.com
Website: Legalize it? Medical evidence on marijuana blows both ways - Sacramento Living - Sacramento Food and Wine, Home, Health | Sacramento Bee
