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Glenn D. Braunstein, M.D. Headshot

Weeding Through Marijuana Facts and Fiction

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In Colorado and Washington, adults now can legally unwind after a tough day at the office by lighting up a joint. Meanwhile, here in California, 17 other states and the District of Columbia, anyone complaining of nearly any ailment, from migraines to menstrual cramps, can seek a prescription for medical marijuana and fill it at a local dispensary, of which there are an estimated 1,000 in Los Angeles.

Voters’ push to loosen marijuana laws reflects widespread public opinion that pot is both beneficial in treating medical conditions and poses little, if any, risk. Is this an accurate perception or a pipe dream?

Marijuana — a.k.a weed, grass, pot, cannabis — is typically a product of the dried flowers, leaves, stems and seeds of the Cannabis sativa plant. It has been used medically, and recreationally, throughout the world for somewhere between 3,000 and 5,000 years. Many believe Chinese emperor Shen-Nung was the first to prescribe it, in 2700 B.C. By the 1800s, marijuana, along with other plant-based remedies, made its way west and into the black leather bags of American physicians, who prescribed the herb for various problems ranging from insomnia to sexual dysfunction.

Today pot is the most widely used illicit substance in the world. An estimated 119 million to 224 million people across the globe used cannabis in 2010. In the United States more than 18 million people older than 12 — roughly seven percent of the population — reported having used marijuana within the past month in 2011.

Despite this long history, we have far less clinical evidence about marijuana’s effects than many other, newer drugs. That’s largely because it’s illegal in most countries. In the United States, pot, like heroin and LSD, is classified as a Schedule I drug. This designation — which appellate courts as recently as Jan. 25 declined to alter — means that, despite state laws, according to the federal government, it has no approved medicinal use and possesses a high potential for abuse. The only authorized source of marijuana for research is grown at the University of Mississippi and is controlled by the National Institute on Drug Abuse, which favors studying potential risks rather than benefits of cannabis. Cannabis’ illegal status also makes it difficult to find funding for research.

Still, some medical benefits have credibly been demonstrated. Marijuana is effective in managing chronic pain, which afflicts about 100 million Americans. It can improve appetite in AIDS patients and can treat nausea and vomiting in cancer patients undergoing chemotherapy.

As for other conditions that marijuana has been touted to treat, like epilepsy and multiple sclerosis, clinical proof is still meager and inconclusive. Pot was once considered a boon for glaucoma patients, but the Glaucoma Foundation does not recommend its use because while it can reduce pressure in sufferers’ eyes, relief lasts only three to four hours. Meaningful help would require multiple doses a day, and since marijuana affects blood pressure, it is possible that it could make glaucoma worse.

Risks commonly associated — though not necessarily caused by marijuana — like its trigger effect for schizophrenia, cognitive decline, and a connection with testicular cancer, aren’t entirely understood either.

Among the most convincing findings for marijuana as medicine is a 2007 study at San Francisco General Hospital, in which marijuana helped relieve peripheral neuropathic pain in HIV patients. Neuropathy, which can be caused by a variety of disorders including cancer chemotherapy, is a debilitating, burning sensation of the hands and feet. This is the condition outspoken Los Angeles City Councilman Bill Rosendahl told the Los Angeles Times he uses marijuana for.

In the San Francisco General study, 25 patients smoked three marijuana joints a day over a five-day period and reported a 34 percent reduction in pain. By comparison, the 25 patients who received placebo cigarettes, which looked and smelled like marijuana but without the active ingredient, THC (short for delta-9 tetrahydrocannabinol), reported only a 17 percent reduction.

Another study at the same hospital, conducted in 2011, found that the addition of marijuana reduced pain for patients already being treated with opioid drugs. When 21 patients taking either long-acting morphine or Oxycontin twice a day added inhaled marijuana via a vaporizer to their regime, pain was decreased by an average of 27 percent. The marijuana did not significantly alter the blood levels of the prescription drugs. This finding might prove helpful in combating the current epidemic of opiate overdoses in our country.

Pot therapy has limitations, though. Marijuana contains more than 480 chemicals, 66 of which are cannabinoids. These interact with receptors in different parts of the brain that control just about everything, including: pleasure, memory, thinking, concentration, movement, coordination, and sensory and time perception. These receptors are abundant and complex. Activation for one purpose can spark other undesired effects. The properties that reduce pain, for example, are entwined with those that elicit mind-altering effects. That may not be a deterrent for someone terminally ill with cancer. But a construction worker with a pinched nerve isn’t going to want to operate a forklift while high.

In addition to relieving pain and eliciting the euphoric “high” feeling that attracts recreational users, marijuana can increase heart rate, appetite and sensory perception; diminish coordination and cause short-term memory loss, anxiety, paranoia and sometimes even psychotic episodes.

Most people smoke pot rather than ingest it in food like brownies or tea, because the effects are immediate. Marijuana contains many of the same toxins as tobacco, but does not appear to diminish lung function the way cigarette smoking does, possibly because marijuana smokers tend to smoke less. In a recent, long-term study of more than 5,000 participants, moderate users — those smoking up to a joint a day for seven years — showed no decline in lung function. There were too few heavy users (those smoking two or more joints a day) in study to evaluate effects among that group. The study did not investigate other lung issues, like cancer or chronic bronchitis.

Mental illness, especially schizophrenia, has long been linked with marijuana use. Many studies suggest that smoking pot, especially in adolescence when the brain is still developing, can trigger schizophrenia in people predisposed to the illness, as well as worsening symptoms in those already diagnosed . But this adds to a persistent conundrum: The prevalence of schizophrenia has remained at about one percent of the population, while marijuana use has increased exponentially over the past six decades.

More recently, researchers have suggested a link between chronic pot use and a decline in intelligence. Last year, a team of international researchers reported observing an eight-point IQ decline among chronic marijuana users who’d begun using in early adolescence. Researchers studied more than 1,000 New Zealanders, who were tested at ages 13 and again at 38. The drop was found among participants who said they had become dependent on the drug by age 18. Critics point out that the decline could be due to participants’ socioeconomic factors, such as income and education that contribute to their adolescent marijuana use.

Either way, teens in this country don’t appear too concerned. Marijuana use among high school students is at a 30-year high. Some 6.5 percent of high school seniors smoke marijuana daily, while 23 percent report having smoked it in the previous month, according to the most recent annual survey funded by the National Institute of Drug Abuse. The report also showed continued popularity for synthetic pot, which is made from herbs and chemicals and mimics pots intoxicating effects. Marketed under names like “spice” and “K2,” synthetic marijuana could be purchased legally until recently.

Experts debate whether marijuana is a “gateway” drug that leads to more serious substance use. However, there’s a general consensus that it is addictive for about 9 percent of users, versus 32 percent for nicotine, 17 percent for cocaine and 15 percent for alcohol.

More alarming: Some 19 percent of teens report having driven stoned, according to a recent survey by Liberty Mutual Insurance and SADD (Students Against Destructive Decisions). More than just teens drive while under pot’s influence: Almost one in five motor vehicle deaths, U.S. auto safety regulators report, involved either cocaine or marijuana use; in a 1994 study of 175 motorists stopped by police in Tennessee for reckless driving, mean age 27, 68 tested positive for marijuana. In California, 7.4 percent of drivers were found to have marijuana in their system, according to a November survey conducted by the California Office of Traffic Safety.

Driving within three hours of smoking marijuana puts you at nearly twice the risk of having an accident that leads to serious injury or death than being sober, according to a recent research review of newly 50,000 drivers in several countries.

One would assume that not getting behind the wheel shortly after toking is a no-brainer. Likewise, common sense suggests little good will come from excessive, chronic recreational marijuana use, or indulgence by adolescents and young adults, in the midst of sensitive brain development. However, occasional use by adults generally is unlikely to cause serious long-term health consequences. But users should be aware that, unregulated by an agency like the FDA, pot’s purity and potency vary greatly.

As for cannabis’ medicinal potential, I strongly urge the federal government to heed the American Medical Association recommendation and review the drug’s classification so more meaningful research can be undertaken. Classifying it as a Schedule II drug, similar to amphetamines and opiates, would go a long way toward moving the field along to better examine its benefits and risks, while still retaining control over its use as a medication. We need more science and less blather from blue-noses and stoners both about a substance as potent as pot. It’s neither a prudent nor productive analogy, at present, to compare marijuana to alcohol or tobacco and to conclude blithely that, as a matter of public policy, just because there are so many users, we should just turn an absolute blind eye; it also has not shifted the situation to call marijuana evil and advocate its elimination as part of a “war” with doubtful outcomes. We’ve grown wiser and more cautious in many ways about booze and cigarettes — for significant, scientific health reasons. We should see marijuana in enlightened fashion, too, neither demonizing nor glorifying it and discussing its role in our lives and our society with eyes wide open and common sense in gear.