The Conversation:

RESEARCH OFFERS CONTRASTING VIEWS OF MARIJUANA

Rickey Yuhre didn't need an $8.7 million California medical marijuana
study to tell him that pot eased his suffering.

The 53-year-old former diesel truck mechanic and welder has pulmonary
fibrosis, a chronic and debilitating disease of the lungs. He has
fused vertebrae in his neck due to severe nerve damage.

Pain meds and relaxants - Oxycontin, Vicodin, Neurontin, Valium -
only turned his insides out with nausea. And so he started using a
special "vapor box" to medicate with marijuana without smoking.

"It brought things to a tolerable state," said Yuhre, of Sacramento.

His experiences seem to support findings of state-funded research
that asserts that marijuana provides relief for a range of ailments,
including neuropathic pain caused by injuries, infections, diabetes,
strokes and other conditions affecting the nervous system.

Funded by the California Legislature, the Center for Medical Cannabis
Research at the University of California, San Diego, since 2000 has
been conducting America's first major clinical research on marijuana
in two decades.

"As a result of this program of systematic research," concluded the
study team, led by medical researcher Dr. Igor Grant, "we now have
reasonable evidence that cannabis is a promising treatment."

But marijuana as medicine may be less than promising when it comes to
gaining widespread political, social and even medical acceptance.

It seems removed from the clinical mainstream when Dr. Nora D.
Volkow, director of the National Institute on Drug Abuse, writes,
"The use of marijuana can produce adverse physical, mental, emotional
and behavioral changes and - contrary to popular belief - it can be addictive."

Volkow's conclusions highlight the U.S. Department of Health and
Human Services "Marijuana Abuse" report. The document, published in
2002 and reprinted in 2003 and 2005, suggests that research indicates
that "marijuana can impair short-term memory, verbal skills and
judgment . and also may weaken the immune system."

Contradictory medical literature may well reflect different emphases
of different researchers. The findings may depend on whether they're
studying cannabis as a cure or a lure, as a potential treatment or a
possible addiction.

"I consider it to be like the 'Blind Man and the Elephant,' " said
Dr. Donald Abrams, chief of oncology at San Francisco General
Hospital and a researcher who has studied the effects of cannabis
since 1997. "Everybody brings their perspective."

Indeed, literature on the effects of marijuana is as varied as the
perceptions of the blind men in poet John Godfrey Saxe's 19th century
fable who reached conflicting conclusions about an elephant based on
whether they touched its trunk, ears or tusk.

Abrams found marijuana beneficial in treating cancer and HIV patients
for nausea, loss of appetite, pain, depression and inability to sleep.

He also wrote in the medical journal Integrative Oncology that "a
growing body of pre-clinical evidence suggests that cannabis may not
only be effective for symptom management, but may have a direct
anti-tumor effect as well."

But Abrams said in an interview: "If I were an addiction researcher,
I might see it from a different perspective - because I would only
see people with problems with this drug."

Last year, the Journal of Psychiatric Research published a study
suggesting that cannabis may adversely affect brain development in
late adolescence.

In that study, led by Manzar Ashtari of the Children's Hospital of
Philadelphia, Ashtari and other researchers performed brain imaging
studies on 14 young men at a drug treatment center in New York.

Ashtari told the LiveScience health website that the study
"reinforces the idea that the adolescent brain may be especially
vulnerable to risky behaviors such as substance abuse." He suggested
more research.

Other studies offer interesting contrasts. They suggest that
marijuana may impair formation of memories in young people. However,
it may reduce mental deterioration in older people.

The National Institute on Drug Addiction report says "heavy marijuana
use impairs a person's ability to form memories."

And yet investigators at California's Scripps Research Institute
reported in 2006 that tetrahydrocannabinol (THC), the psychoactive
ingredient in marijuana, may inhibit an enzyme responsible for
Alzheimer's disease.

Reports also conflict on whether marijuana presents a greater or
lesser risk of lung cancer than tobacco.

In 2006, a UCLA study, funded by the National Institute on Drug
Abuse, found that even heavy marijuana smokers didn't have an
increased risk of cancer. The findings seemed to contradict the
National Institute on Drug Addiction's previous studies suggesting
that marijuana smoke contains 50 to 70 percent more carcinogenic
hydrocarbons than tobacco smoke.

A 2009 report by the American Cancer Society says research on pot's
link to lung cancer is difficult because "it's not easy to gather
information about the use of illegal drugs, and many marijuana
smokers also smoke cigarettes."

Last June, the Office of Environmental Health Hazard Assessment added
marijuana smoke to California's list of carcinogens under Proposition
65, the 1986 law requiring warnings on hazardous chemicals that may
threaten the public's health and well-being.

A research summary published by a pot-legalization group hedges its
bets while touting marijuana's benefits.

The National Organization for Reform of Marijuana Laws' 2009 review
of a decade of scientific literature proclaims pot's effectiveness in
providing relief for amyotrophic lateral sclerosis (Lou Gehrig's
disease), diabetes, hepatitis C, multiple sclerosis, arthritis and
Tourette syndrome.

But the report says some groups, including adolescents, pregnant or
nursing mothers, or people with a history of mental illness, may be
susceptible "to increased risks from the use of cannabis."

"Cannabis is neither a miracle compound nor the answer to everyone's
ills," Dr. Gregory T. Carter, a University of Washington professor of
rehabilitation medicine, wrote in the NORML report. "However, it does
appear to have therapeutic benefits that are there for the asking if
government barriers for more intensive study are removed."

Abrams said his experience in research and recommending marijuana to
patients suggests "the benefits of this drug far outweigh the risks."

And Rahsaan Smith, 36, of Oakland said marijuana is the best remedy
he found for pain from a back injury. He also uses it as an appetite
booster for an intestinal disorder.

"One (marijuana) blunt will last me a day or so. I can hit it a
couple of times and put it out and go back to it when I need it," he
said. "Basically what it does is relax me to where pain isn't my
primary concern. I use the distraction to take care of my bills and
my errands. I actually get more things done after I smoke."

Dr. Barth Wilsey, a University of California, Davis, physician who
studied pot's effectiveness in reducing neuropathic pain, said pain
diminished among subjects who smoked marijuana with both high and low
doses of tetrahydrocannabinol, the psychoactive substance in cannabis.

While the pain relief was the same, those who used the more potent
pot had more problems with memory and diminished motor skills, Wilsey said.

For the others, he said, "there was a feeling of good effect, maybe
feeling stoned or feeling high. But the cognitive impairment wasn't there."

Wilsey is continuing the study with a lower dose to see if subjects
can still find relief, perhaps with little or no psychoactive effect.

But Wilsey laments his initial research involved only 38 people.
"Ideally," he said, "it would be 300 to 400 patients."

At a time of heightened interest in the beneficial or harmful effects
of cannabis, researchers say more extensive studies are essential.

Yet they are stymied by a lack of funding, and political and
bureaucratic hurdles.

Approval of federal drug enforcement and research agencies is
required for supervised clinical trials. Researchers complain that
access to government-grown marijuana, cultivated at the University of
Mississippi, is rigidly controlled and a hurdle to further medical or
scientific studies.

"There is a lot of work that needs to be done, a lot more work," Wilsey said.

And more knowledge to be gleaned.

[sidebar]

MEDICAL MARIJUANA: PANACEA OR PROBLEM?

A community health forum, presented by Capital Public Radio and The
Bee, will feature a panel of experts to discuss the medical, legal
and community impact of medical marijuana. Insight host Jeffrey
Callison will moderate the forum and Bee reporter Peter Hecht will
join the panel of experts. A one-hour live broadcast will begin at 6
p.m. Wednesday on 90.9 FM in Sacramento, 90.5 FM in Tahoe/Reno, and
88.1 FM in Quincy and 91.3 FM in Stockton/Modesto. A Web chat will
begin at 6 p.m. at www.secondopinions.org. For more details, see graphic above.