Health Benefits of Marijuana

A Brief History of Medical Marijuana

While smokable marijuana’s proliferation in North America dates back only a few generations, cannabis has been cultivated and used in other cultures for healing since before recorded history over 10,000 years ago.

The earliest written reference to medical cannabis is found in the 15th century writings of Chinese Emperor Shennong who included notes about cannabis in a book that is considered the world’s oldest pharmacopoeia (a book about medicinal drugs) and where he recommended cannabis for treatment of more than 100 different ailments, including:

  • Gout
  • Rheumatism
  • Malaria
  • Constipation
  • Pain associated with arthritis
  • “Female disorders”
  • And, ironically enough, memory loss

Cannabis has also been used for thousands of years in India, the Middle East, Southeast Asia, and Africa. Archaeological research has proven it was being cultivated in China as early as 4000 B.C. and in Turkestan in 3000 B.C.  And there are reports of the Chinese mixing hemp with wine to make a form of anesthesia that could be used during surgeries in the 17th century.

Here’s a quick historical rundown:

In more modern times, the Irish physician William Brooke O’Shaughnessy is credited with introducing cannabis to the Western medical world in the 1830s. After learning of it during his time as a professor at the Medical College of Calcutta (India), O’Shaughnessy tested the herb on animals and then began prescribing it to his human patients to treat pain and muscle spasms.

O’Shaughnessy’s work ushered in a wave of cannabis research in the Western medical world and established it as a medicine manufactured and marketed to the general public until prohibition began spreading through North America and Europe in the early 1900s.

Medical Marijuana in the United States Today

Marijuana prohibition began in the United States in 1937 with the Marijuana Tax Act, which created mountains of bureaucracy and paperwork, and made legal cannabis practically impossible to obtain even with prescriptions for medical purposes. It was not until 6 decades later that California became the first state to legalize medical marijuana for qualifying patients.

Today, 23 states and the District of Columbia make medical marijuana available to individuals with certain medical conditions when their physicians support or prescribe its use. See if your state is one of the 23, and learn more about your state’s laws and regulations. While the rules that determine who qualifies for medical marijuana vary state to state here are the basics.

Marijuana remains classified as a Schedule 1 controlled substance under the Controlled Substances Act (the same classification given to cocaine and heroin), which means the federal government deems it highly addictive and of no medicinal value. However, the government does continue to conduct research related to marijuana and its medicinal uses. The National Institute on Drug Abuse (NIDA) is one of the primary government institutions that conducts studies on cannabis, THC (cannabis’ psychoactive ingredient), and cannabinoids (chemicals related to THC), including:

In addition to NIDA, the University of California’s Center for Medicinal Cannabis Research (CMCR) conducts ongoing studies related to medical marijuana and is a great source for news on the latest findings in cannabis research.

Cannabis and Its Health Benefits

Note: The information included in this section is not to be used as a substitute for medical advice from your physician and/or other licensed medical professionals. Use this only as a resource to begin a conversation with your healthcare providers. Additionally, because medical marijuana is a relatively new field of research as medical standards go, there is little formal information on the medicinal uses of cannabis that is broadly published – but more emerges each day. We’ve done our best to compile the most pertinent and reliable information available from universities, medical journals, and researchers.

Tags: Cancer, HIV, Adolescents, Aging, Pain, Sleep, Brain, Inflammation, Get Through It


Tags: Cancer, HIV, Adolescents, Aging, Get Through It

Medically speaking, marijuana might be most widely known for its ability to curb nausea and vomiting, especially that which follows cancer treatment (chemotherapy) and HIV treatment (antiretroviral therapy). The National Comprehensive Cancer Network (an alliance of 26 cancer care centers nationwide) even recommends the use of cannabis to curb chemotherapy side effects in its guidelines for treating nausea and vomiting.

  • The National Cancer Institute: “Two cannabinoid drugs approved in the United States [dronabinol and nabilone] … [in many clinical trials] worked as well as or better than some of the weaker FDA-approved drugs to relieve nausea and vomiting.”
  • American Cancer Society: “A number of small studies of smoked marijuana found that it can be helpful in treating nausea and vomiting from cancer chemotherapy.”
  • National Comprehensive Cancer Network: “If medications don’t seem to be working, you might want to consider asking your oncologist to prescribe medical marijuana. The active substance in marijuana [THC] … has been shown to relieve nausea and stimulate appetite in people receiving chemotherapy.”
Pain Relief

Tags: Pain, Adolescents, Aging

Studies have found that marijuana can be used in conjunction with opioids to offer greater pain relief, meaning smaller doses of opioids are necessary. Cannabis has also been shown to help individuals suffering from nerve pain, which may be caused by diabetes, AIDS, spinal cord injuries, and other conditions. However, based on the findings of researchers, marijuana’s ability to curb chronic pain has been widely debated and seems to be less effective in that area.

  • University of California-San Francisco (UCSF): “A UCSF study suggests patients with chronic pain may experience greater relief if their doctors add cannabinoids … to an opiates-only treatment. The findings, from a small-scale study, also suggest that a combined therapy could result in reduced opiate dosages.”
  • Australian National Drug and Alcohol Centre: “Researchers … found that patients with chronic pain who used the drug said it eased their symptoms better than opioid medications.”
  • Oxford University: “Dr. Michael Lee, lead study author from Oxford University’s Centre for Functional Magnetic Resonance Imaging of the Brain, said: ‘We found that with THC, on average, people didn’t report any change in the burn, but the pain bothered them less … Cannabis does not seem to act like a conventional pain medicine. Some people respond really well, others not at all, or even poorly.”
  • The Neuropathy Journal:  “Marijuana has long carried a negative stigma, but thanks to recent studies, we are confirming its ability to treat many afflictions, including chronic neuropathic pain.”
  • University of California Davis: “Researchers at UC Davis have concluded that medical marijuana can help blunt nerve pain stemming from a variety of causes. The study of 38 patients experiencing neuropathic pain from diabetes, spinal injury, multiple sclerosis and other conditions found they could reduce pain for up to five hours by smoking marijuana.”
Rheumatoid Arthritis

Tags: Pain, Aging, Inflammation

Studies have shown that marijuana can alleviate the symptoms of rheumatoid arthritis, including pain, inflammation, and loss of sleep.

  • Journal of Rheumatology (Oxford): “Investigators reported that administration of cannabis extracts over a five week period produced statistically significant improvements in pain on movement, pain at rest, quality of sleep, inflammation and intensity of pain compared to placebo.” (from NORML)
HIV Treatment

Tags: HIV, Adolescents, Aging, Get Through It

Treatment for HIV can be difficult for patients, in particular antiretroviral therapy (ART). Studies have shown that medical cannabis can help patients adhere to ART, most likely because of its ability to curb nausea. In addition, cannabis stimulates appetite, which helps combat weight loss associated with HIV and its treatment, and can help reduce patient anxiety.

Some studies have also found that THC may actually help slow the physiological impact of HIV on the body by helping patients maintain higher levels of the healthy cells customarily attacked and killed by the infection.

  • National Center for Biotechnology Information (NCBI): “Data suggests that medicinal use of marijuana may facilitate, rather than impede, ART adherence for patients with nausea, in contrast to the use of other illicit substances, which were associated with lower rates of ART adherence.”
  • Louisiana State University: “For 17 months, scientists administered a daily dose of THC, an active ingredient in cannabis, to monkeys infected with an animal form of the virus. Over the course of that period, scientists found that damage to immune tissue in the primates’ stomachs, one of the most common areas in the body for HIV infection to spread, decreased.” (from news article)
Multiple Sclerosis

Tags: Pain, Sleep

Multiple sclerosis (MS) can result in debilitating muscle spasms and stiffness that can make it difficult to move and that disturb sleep. Cannabis-based medicine has been shown to help with both those symptoms. In Europe, doctors often prescribe Sativex for MS, an oral spray that includes THC and cannabidiol (CBD).

  • European Journal of Neurology: “A controlled study found that nabiximols (Sativex®, GW Pharmaceuticals plc), an oral spray derived from Cannabis, significantly improved spasticity in a proportion of people with MS who had been identified as likely to respond to the therapy.” (from National MS Society)
  • NCBI: “The MUSEC study … evaluated oral cannabis extract for treating muscle stiffness in 400 people with all types of MS. In this study muscle stiffness improved by almost twofold in the group taking cannabis extract compared to placebo, and improvements were also noted in body pain, spasms and sleep quality. The most frequent adverse events were urinary tract infections, dizziness, dry mouth and headache.”
Parkinson’s Disease

Tags: Aging, Pain, Sleep

Research on medical marijuana’s effect on Parkinson’s Disease is limited. It appears that cannabis can help with the painful muscle tightness patients may experience, as well as sleep and overall quality of life, but more research is needed to learn more about the impact of cannabis on motor symptoms (tremors, shaking, etc.).

  • NCBI: “There was also significant improvement of sleep and pain scores. No significant adverse effects of the drug were observed.”
Brain Trauma

Tags: Brain

Evidence has shown that marijuana can help protect and possibly heal the brain following stroke, concussion, and other trauma. It seems that marijuana can lessen brain bruising and spur the brain’s healing mechanisms.

  • Cerebral Cortex (Oxford): “The endocannabinoid system (ECS) plays an important role in reparative mechanisms and inflammation under pathological situations by controlling some mechanisms that are shared with minocycline pathways [which mediate the release of harmful molecules that hurt the brain following trauma].”
  • University of Nottingham: “Researchers at the University of Nottingham conducted a meta-analysis of experimental studies into cannabinoids; chemicals related to those found in cannabis, some of which also occur naturally in the body. The findings showed that the compounds could reduce the size of stroke and improve neurological function.”

Tags: Adolescents, Sleep

Research has shown that marijuana can help prevent epileptic seizures in rats, especially in hard-to-treat forms of epilepsy. The findings state that THC may actually control the brain cells that trigger seizures. More research is needed on humans, but parents report that CBD is one – and in some cases the only – method for getting their children’s seizures under control.

  • Virginia Commonwealth University: “The team injected chronically epileptic rats with different combinations of six drugs … The marijuana extract and synthetic marijuana drugs completely eliminated the rats’ seizures, which averaged three over a 10-hour period.”
  • NCBI: “This survey explored the use of cannabidiol-enriched cannabis in children with treatment-resistant epilepsy … Sixteen (84%) of the 19 parents reported a reduction in their child’s seizure frequency while taking cannabidiol-enriched cannabis. Of these, two (11%) reported complete seizure freedom, eight (42%) reported a greater than 80% reduction in seizure frequency, and six (32%) reported a 25-60% seizure reduction. Other beneficial effects included increased alertness, better mood, and improved sleep. Side effects included drowsiness and fatigue.”

Tags: Aging, Pain

It seems glaucoma is a condition that is frequently cited as one that benefits from medical cannabis. Research has shown that marijuana helps relieve intraocular (eye) pressure for 3-4 hours at a time; however, prescription medications offer longer-lasting relief.

  • British Journal of Ophthalmology: “Cannabinoids have the potential of becoming a useful treatment for glaucoma, as they seem to have neuroprotective properties and effectively reduce intraocular pressure. However, several challenges need to be overcome, including the problems associated with unwanted systemic side effects (psychotropic, reduction in systemic blood pressure), possible tolerance, and the difficulty in formulating a stable and effective topical preparation.”
  • The National Academies Press: “Glaucoma … is one of the indications for which the federal government once granted permission for compassionate marijuana use … But, as will be described, other treatments for the disorder have since eclipsed marijuana-based medicines.”
Crohn’s Disease

Tags: Pain, Inflammation

Studies from universities in Israel show that marijuana works for those suffering from Crohn’s Disease (an inflammatory bowel disease) who did not respond to traditional treatment. Nearly half of the patients who treated their condition with cannabis saw the disease go into complete remission (it did, however, return once the study ended and they were no longer using cannabis).

  • NCBI: “Complete remission was achieved by 5 of 11 subjects in the cannabis group (45%) and 1 of 10 in the placebo group (10%). A clinical response was observed in 10 of 11 subjects in the cannabis group (90%) and 4 of 10 in the placebo group (40%). Three patients in the cannabis group were weaned from steroid dependency. Subjects receiving cannabis reported improved appetite and sleep, with no significant side effects.”
General Inflammation

Tags: Inflammation, Pain

Using cannabis products – including topical creams – to treat reddened, swollen, hot, and painful areas has proven to be effective. Scientists have found that components of cannabis activate a receptor in the body (CB2) that plays a pivotal role in inhibiting inflammation.

  • NCBI: “The fact that both CB1 and CB2 receptors have been found on immune cells suggests that cannabinoids play an important role in the regulation of the immune system. Recent studies demonstrated that administration of THC into mice triggered marked apoptosis in T cells and dendritic cells, resulting in immunosuppression. In addition, several studies showed that cannabinoids downregulate cytokine and chemokine production and, in some models, upregulate T-regulatory cells (Tregs) as a mechanism to suppress inflammatory responses..”
  • European Journal of Allergy and Clinical Immunology: “Topically applied THC can effectively attenuate contact allergic inflammation … This has important implications for the future development of strategies to harness cannabinoids for the treatment of inflammatory skin diseases.”
Stopping Cancer

Tags: Cancer, Adolescents, Aging

Research is finding that it may be possible to treat cancer with cannabis. In clinical studies using mice and rats, cannabis stifled tumor growth and killed cancer cells while protecting normal cells – meaning the cancer was prevented from spreading.

  • National Cancer Institute: “Studies in mice and rats have shown that cannabinoids may inhibit tumor growth by causing cell death, blocking cell growth, and blocking the development of blood vessels needed by tumors to grow. Laboratory and animal studies have shown that cannabinoids may be able to kill cancer cells while protecting normal cells.”
  • St. George’s, University of London: “A team of researchers from St. George’s University of London outlined the ‘dramatic reductions’ they observed in high-grade glioma masses, a deadly form of brain cancer, when treated with a combination of radiation and two different marijuana compounds, also known as cannabinoids. In many cases, those tumors shrunk to as low as one-tenth the sizes of those in the control group.” (from news article)
  • National Institute on Drug Abuse (NIDA): “Recent animal studies have shown that marijuana can kill certain cancer cells and reduce the size of others. Evidence from one animal study suggests that extracts from whole-plant marijuana can shrink one of the most serious types of brain tumours. Research in mice showed that these extracts, when used with radiation, increased the cancer-killing effects of the radiation.”
Stress and Anxiety

Tags: Brain

Anecdotal evidence has long stated that marijuana can help relieve stress and anxiety. Some formal studies seem to support that low doses of cannabis can calm nerves though high doses may have the opposite effect. Researchers speculate that anxiety disorders may be caused by abnormalities in the endocannabinoid system of the brain, which is the same system affected by marijuana.

  • Vanderbilt University: “An international group led by Vanderbilt University researchers has found cannabinoid receptors, through which marijuana exerts its effects, in a key emotional hub in the brain involved in regulating anxiety and the flight-or-fight response .. The discovery may help explain why marijuana users say they take the drug mainly to reduce anxiety.”
  • Trends in Pharmacological Sciences: “The discovery of the ECB system raised the possibility that ECBs could be important modulators of anxiety, and might contribute to individual differences in anxious temperament and risk for anxiety disorders. It also led to the notion that targeting components of the ECB system could represent a novel therapeutic approach to developing effective anxiolytic medications devoid of the unwanted effects of cannabis (e.g., cognitive impairment, abuse liability).”
Post-Traumatic Stress Disorder (PTSD)

Tags: Brain, Sleep

For patients suffering from Post-Traumatic Stress Disorder (PTSD), medical marijuana may be able to alleviate symptoms such as stress, anxiety, and nightmares. A study on rats found that marijuana triggers changes in the part of the brain associated with traumatic memories. Though a growing number of states include PTSD as a qualifying condition for medical marijuana, there have been no controlled clinical studies on humans to test marijuana’s effectiveness in treating PTSD.

  • Journal of Neuropsychopharmacology: “The administering of synthetic cannabinoids to rats after a traumatic event can prevent behavioral and physiological symptoms of PTSD by triggering changes in brain centers associated with the formation and holding of traumatic memories.” (from news article)
  • NCBI: “Experiments in animals show that tetrahydrocannabinol, the chemical that gives marijuana its feel-good qualities, acts on a system in the brain that is ‘critical for fear and anxiety modulation,’ says Andrew Holmes, a researcher at the National Institute on Alcohol Abuse and Alcoholism. But he and other brain scientists caution that marijuana has serious drawbacks as a potential treatment for PTSD.” (from news article)
Alzheimer’s and Dementia

Tags: Aging, Brain

Cannabis may be able to slow the progression of Alzheimer’s disease, which is the leading cause of dementia among the elderly, because THC stifles the creation of plaques that kill brain cells and cause Alzheimer’s. Research has only been conducted on cells, with no studies to date performed on humans.

  • Molecular Pharmaceutics: “Here, we demonstrate that the active component of marijuana, THC, competitively inhibits the enzyme acetylcholinesterase (AChE) as well as prevents AChE-induced amyloid β-peptide (Aβ) aggregation, the key pathological marker of Alzheimer’s disease … Compared to currently approved drugs prescribed for the treatment of Alzheimer’s disease, THC is a considerably superior inhibitor of Aβ aggregation, and this study provides a previously unrecognized molecular mechanism through which cannabinoid molecules may directly impact the progression of this debilitating disease.”
  • Journal of Alzheimer’s Disease: “THC is known to be a potent antioxidant with neuroprotective properties, but this is the first report that the compound directly affects Alzheimer’s pathology by decreasing amyloid beta levels, inhibiting its aggregation, and enhancing mitochondrial function … Decreased levels of amyloid beta means less aggregation, which may protect against the progression of Alzheimer’s disease. Since THC is a natural and relatively safe amyloid inhibitor, THC or its analogs may help us develop an effective treatment in the future.” (from news article)
Hepatitis C Treatment

Tags: Pain, Nausea, Get Through It

As with some treatments for other serious conditions, hepatitis C treatment can result in nausea, loss of appetite, and depression. Studies have found that marijuana users completed Hep-C treatment at a much higher rate than non-users, possibly because of the ability of cannabis to curb these side effects.

  • European Journal of Gastroenterology & Hepatology: “Our results suggest that modest cannabis use may offer symptomatic and virological benefit to some patients undergoing HCV treatment by helping them maintain adherence to the challenging medication regimen.”