Critics say the medicinal marijuana movement has simply provided a cover for people who want to get high. Certainly, many of the people lining up at dispensaries with prescriptions for marijuana in Denver and San Francisco don't appear to be seriously ill. Opponents also worry that the presence of storefront dispensaries could make it easier for young people to get access to marijuana.
To date, 14 states and the District of Columbia have legalized medical marijuana. And it's no surprise that some of the most impassioned advocates for access are seniors. Many of the purported health benefits of marijuana target problems that typically plague older people, such as chronic shingles, arthritis pain, loss of appetite and symptoms of multiple sclerosis.
Pot for pain
Researchers acknowledge that they're only beginning to study medical applications of marijuana. "But what we already know suggests that the active compounds in marijuana have tremendous potential," says Mark Ware, M.D., a researcher at McGill University in Montreal and executive director of the Canadian Consortium for the Investigation of Cannabinoids.
Cells throughout the body, he explains, possess receptors for cannabinoids, the active ingredients in marijuana. Interestingly, our bodies produce natural cannabinoids, which are believed to play a role in controlling nerve impulses, immune function and even bone growth. The existence of this naturally occurring system explains why marijuana, by delivering a potent dose of cannabinoids, has far-ranging effects, Ware says.
"Marijuana appears to be particularly effective at easing pain related to nerve damage, or neuropathy."
Among the best-studied benefits are pain control and nausea relief. "Marijuana appears to be particularly effective at easing pain related to nerve damage, or neuropathy," says Stephen Yazulla, professor of neurobiology and behavior at Stony Brook University in New York. Neuropathy is a common complication of diabetes, cancer therapies and herpes zoster infections, or shingles. Marijuana has also been shown to help restore appetite, which can be zapped by cancer treatments. There's emerging evidence that cannabis helps control spastic muscle contractions associated with multiple sclerosis. It may also slow the course of the devastating degenerative nerve disease amyotrophic lateral sclerosis, or Lou Gehrig's disease.
Mainstream medical support
Mainstream medical organizations have acknowledged marijuana's promise. In 2008, the American College of Physicians released a position statement arguing that promising results from small studies should be an impetus to more research into the health effects of marijuana. A 2009 interim report issued by the American Medical Association also argued for more research, pointing to a variety of health benefits.
This isn't the first time the AMA has argued in favor of marijuana. Cannabis was commonly used for medicinal purposes in the United States until 1937, when the weed was declared an illegal substance by the federal government — despite the AMA's objections at the time.
Still illegal after all these years
One reason researchers don't know more about marijuana's potential benefits today is that the federal Controlled Substances Act still classifies marijuana as a Schedule I drug, a category reserved for dangerous drugs with a high potential for abuse and "no currently accepted medical use."
Many researchers dispute both parts of that description. There's growing evidence for medical uses of the weed, they insist. "And when people use it medicinally, there's very little reason to think it leads to abuse," says Yazulla. "No one has ever died from using marijuana, as far as we know."