medical marijuana

Medical Marijuana benefits are largely unproven and poorly documented, study finds

An extensive meta-analysis of 79 trials that studied the medical benefits of marijuana found that the various cannabinoid compounds did not improve nausea, vomiting, or appetite, but slightly improved chronic pain and plasticity. Moreover, most of the studies were poorly made, lacking control or placebo groups and also showing increased risk of bias. In short, this rigorous analysis found no conclusive evidence that supports the much heralded added benefits of medical marijuana. Side effects were common and included dizziness, dry mouth and sleepiness. The authors note that this doesn’t mean that marijuana compounds aren’t working as advertised, it’s just that the science so far is inconclusive – mainly because of bad reporting and investigative techniques. They suggest more research is necessary, along with more support from the authorities and other able bodies given that we’re talking about an extremely widespread drug ingested by millions of Americans each day, legally or not.

medical marijuana

Photo: AP/Damian Dovarganes

“It’s not a wonder drug but it certainly has some potential,” said Dr. Robert Wolff, a co-author and researcher with Kleijnen Systematic Reviews Ltd., a research company in York, England.

Wolff, Penny Whiting, of University Hospitals Bristol NHS in England and their colleagues looked for randomized, controlled trials testing cannabis, or cannabinoid-based medications and eventually settled with 79 trials with 6,462 participants. Patients included those suffering from chemotherapy-related nausea and vomiting, HIV/AIDS-stunted appetite, chronic pain, or paraplegia, or spasms related to multiple sclerosis (MS). The researchers concluded that of these studies only 5% had a low risk of bias, and 70% were considered high risk mostly due to lack of double-blinding and placebo controls.

Poor cannabis science

Concerning nausea and vomiting in chemotherapy patients, 28 of the trails discussed treating these conditions with marijuana compounds like nabilone, dronabinol, nabiximols, levonantradol, and THC. The effects were compared with other drugs like prochlorperazine, chlorpromazine, domperidone, alizapride, hydroxyzine, metoclopramide, and ondansetron. Again, the researchers note the unreliability of the reported studies: 23 of these trials have a high risk of bias, while the other five are unclear. As for results, compared with placebo in three of the trials, chemotherapy patients who were on dronabinol or nabiximols were more likely to have nausea or vomiting.

In the case of HIV/AIDS patients, those studies that assessed improved appetite following cannabis consumption had “limited findings” and high risk of bias. Most research was done on treating chronic pain (28 of the trials)  with smoked, vaporized or other forms of cannabis compound consumption. With one exception, all of these studies were placebo controlled. Whiting’s team reported that only two of the studies had a low risk for bias, and 17 had a high risk. Nevertheless, most studies reported a slight improvement in pain when ingesting cannabinoids, but the results bore little statistical relevance. Patients who smoked THC reported the greatest reduction in pain, especially when dealing with neuropathic pain.

On a federal level, cannabis is illegal but twenty-three states and Washington, D.C. have laws permitting medical marijuana use. In the published paper in the Journal of the American Medical Association, the authors warn that medical marijuana approval was based on poorly conducted studies, patient testimonials and other evidence borderline-scientific at best. For instance, marijuana is approved as a medical drug for treating Alzheimer’s disease, epilepsy, glaucoma, kidney disease, lupus and Parkinson’s disease despite there’s little evidence to support such a measure.

Marijuana “is a complex of more than 400 compounds including flavonoids and terpenoids and approximately 70 cannabinoids other than delta-9-tetrahydrocannabinol (THC),” they wrote, (most FDA approved drugs contain one to several compounds, not hundreds). “These cannabinoids have individual, interactive, and even entourage effects (effects of a compound that are only appreciable in the presence of other compounds) that are not fully understood and that contribute to the net effect of marijuana.”

“If the states’ initiative to legalize medical marijuana is merely a veiled step toward allowing access to recreational marijuana, then the medical community should be left out of the process, and instead marijuana should be decriminalized,” they wrote. “Evidence justifying marijuana use for various medical conditions will require the conduct of adequately powered, double-blind, randomized, placebo/active controlled clinical trials to test its short- and long-term efficacy and safety.”

It’s not just the benefits that are inconclusive. The same applies to the adverse events as well. In 62 of the studies, adverse events were reported, and Whiting’s team stated that they did not see much difference in adverse events based on the type of cannabinoid used or study design. These include dizziness, dry mouth, nausea, fatigue, somnolence, euphoria, vomiting, disorientation, drowsiness, confusion, loss of balance, and hallucination.

So, what’s going on? Why is a drug so widely used in the US and abroad so poorly studied? Well, even now when there’s medical marijuana freely available in most states, getting approval from the FDA and DEA to perform studies with cannabis is extremely difficult and involves a cumbersome process, which sounds stupid. Well, it is. Things might improve soon as the Department of Health and Human Services made it a little easier for privately funded medical marijuana research to get approved. Whatever the future will hold, I can only hope we’ll see rigorous research and more support.

“Perhaps it is time to place the horse back in front of the cart,” Drs. Deepak Cyril D’Souza and Mohini Ranganathan wrote in the editorial.

In other marijuana related news, another paper published in the same journal found that the medical marijuana to eat and drink doesn’t contain advertised THC levels. After analyzing the contents of 47 brands, including candy, baked goods and drinks, sold in dispensaries in Los Angeles, San Francisco and Seattle, the researchers found 1 in 4 had higher amounts than labeled. Oppositely, 60% of the products contained less THC than advertised. Some barely contained any cannabis, which sounds like a rip-off.


9 thoughts on “Medical Marijuana benefits are largely unproven and poorly documented, study finds

  1. Eric

    When you read the study, you realize that it has almost nothing to do with marijuana. Most of the studies used synthetic THC which we know is not as effective and comes with substantial side-effects. This is not a study about medical marijuana and should not be billed as such. Even the author admits there are many, dozens, of other compounds in marijuana that are not found in synthetic THC medications.

  2. Peter

    When I read the description of the study on
    I read it has 25% more effective on pain and >100% efficative index nausea. I could be wrong read for yourself here’s the quote
    “associated with a greater average number of patients showing a complete nausea and vomiting response (47% vs 20%; odds ratio [OR], 3.82 [95% CI, 1.55-9.42]; 3 trials), reduction in pain (37% vs 31%; OR, 1.41 [95% CI, 0.99-2.00]; 8 trials), a greater average reduction in numerical rating scale pain assessment (on a 0-10-point scale; weighted mean difference [WMD], −0.46 [95% CI, −0.80 to −0.11]; 6 trials), and average reduction in the Ashworth spasticity scale (WMD, −0.36 [95% CI, −0.69 to −0.05]; 7 trials).”

  3. Brian Kelly

    Politicians who continue to demonize Medical Marijuana, Corrupt Law Enforcement Officials who prefer to ruin peoples lives over Marijuana possession rather than solve real crimes who fund their departments toys and salaries with monies acquired through Marijuana home raids, seizures and forfeitures, and so-called “Addiction Specialists” who make their income off of the judicial misfortunes of our citizens who choose marijuana, – Your actions go against The Will of The People and Your Days Are Numbered! Find new careers before you don’t have one.

    The People have spoken! Get on-board with Medical Marijuana Legalization Nationwide, or be left behind and find new careers. Your choice.

    There is absolutely no doubt now that the majority of Americans want our politicians to provide us safe, legal access to Medical Marijuana Nationwide. Our numbers grow on a daily basis.

    The prohibitionist view on medical marijuana is the viewpoint of a minority of Americans.. It is based upon decades of lies and propaganda.

    Each and every tired old lie they have propagated has been thoroughly proven false by both science and society.

    Their tired old rhetoric no longer holds any validity. The majority of Americans have seen through the sham of medical marijuana prohibition in this day and age. The number of prohibitionists left shrinks on a daily basis.

    With their credibility shattered, and their not so hidden agendas visible to a much wiser public, what’s left for a medical marijuana prohibitionist to do?

    Maybe, just come to terms with the fact that Medical Marijuana Legalization Nationwide is an inevitable reality that’s approaching much sooner than prohibitionists think, and there is nothing they can do to stop it!

    Legalize Nationwide!…and Support All Medical Marijuana Legalization Efforts!

  4. Brian Kelly

    While U.S. officials defend their monopoly, critics say the government is hogging all the pot and giving it mainly to researchers who want to find harms linked to the drug.

    U.S. officials say the federal government must be the sole supplier of legal marijuana in order to comply with a 1961 international drug-control treaty. But they admit they’ve done relatively little to fund pot research projects looking for marijuana’s benefits, following their mandate to focus on abuse and addiction.

    “We’ve been studying marijuana since our inception. Of course, the large majority of that research has been on the deleterious effects, the harmful effects, on cognition, behavior and so forth,” said Steven Gust, special assistant to the director at the National Institute on Drug Abuse, which was created in 1974.

  5. Brian Kelly

    When a loved one is in pain, wasting away unable to eat, and needs this marvelous herb in order to increase their appetite, reduce the overwhelming pain, and live as as healthy and happily as they can with the time they have left, let’s have the compassion to allow them to have it.

    Stop treating Medical Marijuana Patients like second rate citizens and common criminals by forcing them to the dangerous black market for their medicine.

    Risking incarceration to obtain the medicine you need is no way to be forced to live.

    Support Medical Marijuana Now!

    “[A] federal policy that prohibits physicians from alleviating suffering by prescribing marijuana for seriously ill patients is misguided, heavy-handed, and inhumane.” — Dr. Jerome Kassirer, “Federal Foolishness and Marijuana,” editorial, New England Journal of Medicine, January 30, 1997

    “[The AAFP accepts the use of medical marijuana] under medical supervision and control for specific medical indications.” — American Academy of Family Physicians, 1989, reaffirmed in 2001

    “[We] recommend … allow[ing] [marijuana] prescription where medically appropriate.” — National Association for Public Health Policy, November 15, 1998

    “Therefore be it resolved that the American Nurses Association will: — Support the right of patients to have safe access to therapeutic marijuana/cannabis under appropriate prescriber supervision.” — American Nurses Association, resolution, 2003

    “The National Nurses Society on Addictions urges the federal government to remove marijuana from the Schedule I category immediately, and make it available for physicians to prescribe. NNSA urges the American Nurses’ Association and other health care professional organizations to support patient access to this medicine.” — National Nurses Society on Addictions, May 1, 1995

    “[M]arijuana has an extremely wide acute margin of safety for use under medical supervision and cannot cause lethal reactions … [G]reater harm is caused by the legal consequences of its prohibition than possible risks of medicinal use.” — American Public Health Association, Resolution #9513, “Access to Therapeutic Marijuana/Cannabis,” 1995

    “When appropriately prescribed and monitored, marijuana/cannabis can provide immeasurable benefits for the health and well-being of our patients … We support state and federal legislation not only to remove criminal penalties associated with medical marijuana, but further to exclude marijuana/cannabis from classification as a Schedule I drug.” — American Academy of HIV Medicine, letter to New York Assemblyman Richard Gottfried, November 11, 2003

  6. Brian Kelly

    International and National Organizations

    AIDS Action Council
    AIDS Treatment News
    American Academy of Family Physicians
    American Medical Student Association
    American Nurses Association
    American Preventive Medical Association
    American Public Health Association
    American Society of Addiction Medicine
    Arthritis Research Campaign (United Kingdom)
    Australian Medical Association (New South Wales) Limited
    Australian National Task Force on Cannabis
    Belgian Ministry of Health
    British House of Lords Select Committee on Science and Technology
    British House of Lords Select Committee On Science and Technology (Second Report)
    British Medical Association
    Canadian AIDS Society
    Canadian Special Senate Committee on Illegal Drugs
    Dr. Dean Edell (surgeon and nationally syndicated radio host)
    French Ministry of Health
    Health Canada
    Kaiser Permanente
    Lymphoma Foundation of America
    The Montel Williams MS Foundation
    Multiple Sclerosis Society (Canada)
    The Multiple Sclerosis Society (United Kingdom)
    National Academy of Sciences Institute Of Medicine (IOM)
    National Association for Public Health Policy
    National Nurses Society on Addictions
    Netherlands Ministry of Health
    New England Journal of Medicine
    New South Wales (Australia) Parliamentary Working Party on the Use of Cannabis for Medical Purposes
    Dr. Andrew Weil (nationally recognized professor of internal medicine and founder of the National Integrative Medicine Council)

    State and Local Organizations

    Alaska Nurses Association
    Being Alive: People With HIV/AIDS Action Committee (San Diego, CA)
    California Academy of Family Physicians
    California Nurses Association
    California Pharmacists Association
    Colorado Nurses Association
    Connecticut Nurses Association
    Florida Governor’s Red Ribbon Panel on AIDS
    Florida Medical Association
    Hawaii Nurses Association
    Illinois Nurses Association
    Life Extension Foundation
    Medical Society of the State of New York
    Mississippi Nurses Association
    New Jersey State Nurses Association
    New Mexico Medical Society
    New Mexico Nurses Association
    New York County Medical Society
    New York State Nurses Association
    North Carolina Nurses Association
    Rhode Island Medical Society
    Rhode Island State Nurses Association
    San Francisco Mayor’s Summit on AIDS and HIV
    San Francisco Medical Society
    Vermont Medical Marijuana Study Committee
    Virginia Nurses Association
    Whitman-Walker Clinic (Washington, DC)
    Wisconsin Nurses Association

    Additional AIDS Organizations

    The following organizations are signatories to a February 17, 1999 letter to the US Department of Health petitioning the federal government to “make marijuana legally available … to people living with AIDS.”

    AIDS Action Council
    AIDS Foundation of Chicago
    AIDS National Interfaith Network (Washington, DC)
    AIDS Project Arizona
    AIDS Project Los Angeles
    Being Alive: People with HIV/AIDS Action Committee (San Diego, CA)
    Boulder County AIDS Project (Boulder, CO)
    Colorado AIDS Project
    Center for AIDS Services (Oakland, CA)
    Health Force: Women and Men Against AIDS (New York, NY)
    Latino Commission on AIDS
    Mobilization Against AIDS (San Francisco, CA)
    Mothers Voices to End AIDS (New York, NY)
    National Latina/o Lesbian, Gay, Bisexual And Transgender Association
    National Native American AIDS Prevention Center
    Northwest AIDS Foundation
    People of Color Against AIDS Network (Seattle, WA)
    San Francisco AIDS Foundation
    Whitman-Walker Clinic (Washington, DC)

    Other Health Organizations

    The following organizations are signatories to a June 2001 letter to the US Department of Health petitioning the federal government to “allow people suffering from serious illnesses … to apply to the federal government for special permission to use marijuana to treat their symptoms.”

    Addiction Treatment Alternatives
    AIDS Treatment Initiatives (Atlanta, GA)
    American Public Health Association
    American Preventive Medical Association
    Bay Area Physicians for Human Rights (San Francisco, CA)
    California Legislative Council for Older Americans
    California Nurses Association
    California Pharmacists Association
    Embrace Life (Santa Cruz, CA)
    Gay and Lesbian Medical Association
    Hawaii Nurses Association
    Hepatitis C Action and Advisory Coalition
    Life Extension Foundation
    Maine AIDS Alliance
    Minnesota Nurses Association
    Mississippi Nurses Association
    National Association of People with AIDS
    National Association for Public Health Policy
    National Women’s Health Network
    Nebraska AIDS Project
    New Mexico Nurses Association
    New York City AIDS Housing Network
    New York State Nurses Association Ohio Patient Network Okaloosa AIDS Support and Information Services (Fort Walton, FL)
    Physicians for Social Responsibility – Oregon
    San Francisco AIDS Foundation
    Virginia Nurses Association
    Wisconsin Nurses Association

    Health Organizations Supporting Medical Marijuana Research

    International and National Organizations

    American Cancer Society
    American Medical Association
    British Medical Journal
    California Medical Association
    California Society on Addiction Medicine
    Congress of Nursing Practice
    Gay and Lesbian Medical Association
    Jamaican National Commission on Ganja
    National Institutes of Health (NIH) Workshop on the Medical Utility of Marijuana
    Texas Medical Association
    Vermont Medical Society
    Wisconsin State Medical Society

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