The first U.S. clinical trials in more than 20 years on the medical efficacy of marijuana found that pot helps relieve pain and muscle spasms associated with multiple sclerosis and certain neurological conditions, according to a report released Wednesday by a UC research center.

The results of five state-funded scientific clinical trials came 14 years after California voters passed a law approving marijuana for medical use and more than 10 years after the state Legislature passed a law that created the Center for Medicinal Cannabis Research at UC San Diego, which conducted the studies.

Dr. Igor Grant, a UC San Diego psychiatrist who directs the center, called the report "good evidence" that marijuana would be an effective front-line treatment for neuropathy, a condition that can cause tingling, numbness and pain.

"We focused on illnesses where current medical treatment does not provide adequate relief or coverage of symptoms," Grant said. "These findings provide a strong science-based context in which policymakers and the public can begin discussing the place of cannabis in medical care."

Despite California's passage in 1996 of Proposition 215, which allows patients with a valid doctor's recommendation to grow and possess marijuana for personal medical use, the federal government classifies marijuana as an illicit drug with no medical use and has closed pot clubs and prosecuted suppliers. Thirteen other states have passed similar measures legalizing medical marijuana.

Proponents of medical marijuana see Wednesday's news as the turning of the tide for what they hope would become federal acceptance of pot's therapeutic benefits.

A first step

"This is the first step in approaching the (U.S. Food and Drug Administration), which has invested absolutely nothing in providing scientific data to resolve the debate," said state Sen. Mark Leno, D-San Francisco, who noted that marijuana showed benefits throughout the AIDS epidemic in helping people afflicted with neuropathy and other ailments.

Dale Gieringer, a Berkeley resident who is executive director of the California branch of the National Organization for the Reform of Marijuana Laws, agreed.

"This is finally the evidence that shows that the (U.S. Drug Enforcement Administration) stance that marijuana does not have medical use is just wrong," he said. "It's time for the Obama administration to act."

During the study, volunteers were randomly given marijuana or placebos.

The marijuana was obtained through the University of Mississippi, which has a contract with the federal government to provide the only pot that can be used for scientific research. Grant said the research required heavy federal oversight.

Long-term issues

He noted volunteers had the same amount of pain reduction with low doses of THC, the psychoactive ingredient in marijuana, compared with high doses of THC. He also said evidence casts doubt on long-term negative impacts of marijuana use, while acknowledging there have not been formal studies on the question.

"There is not very strong evidence that marijuana, for example, produces emphysema or lung cancer or permanent brain damage," Grant said.

That doesn't mean marijuana is harmless, he said. "Anything you smoke in a combustible form has potential risks, but the safety profile seems to be better for it than some other drugs like tobacco," he said.

The Center for Medicinal Cannabis Research has approved 15 clinical studies, five of which were completed and reported Wednesday, and two are in progress. While researchers said more studies are needed, the future of the center is in doubt.

The center has spent all but $400,000 of the $8.9 million in research funding it started with in 1999. Leno said the state doesn't have the money to continue funding it.

"It may be close to the end of its life unless there's foundation money to continue the work," Leno said.