Despite the fact that the Drug Enforcement Agency categorizes marijuana as a schedule I drug, one that has no accepted medical use, a majority of Americans have thought medical pot should be legal since the late 1990s — and a majority now support recreational legalization as well.
Even the NIH’s National Institute on Drug Abuse lists medical uses for cannabis.
But even though researchers have identified some fascinating potential benefits of medical marijuana so far, it’s something that’s still hard to study, making conclusive results tough to come by. The schedule I classification means it’s hard for researchers to get their hands on pot grown to the exacting standards that are necessary for medical research, even in states where it’s legal. Plus, no researcher can even try to make an FDA-approved cannabis product while it has that DEA classification, which removes some motivation to study the plant.
More research would identify health benefits more clearly and would also help clarify potential dangers such as with any psychoactive substance, there are risks associated with abuse, including dependency and emotional issues. And many doctors want to understand marijuana’s effects better before deciding whether to recommend it or not.
There’s a fair amount of evidence that marijuana does no harm to the lungs, unless you also smoke tobacco, and one study published in Journal of the American Medical Association found that marijuana not only doesn’t impair lung function, it may even increase lung capacity.
Researchers looking for risk factors of heart disease tested the lung function of 5,115 young adults over the course of 20 years. Tobacco smokers lost lung function over time, but pot users actually showed an increase in lung capacity.
It’s possible that the increased lung capacity may be due to taking a deep breaths while inhaling the drug and not from a therapeutic chemical in the drug.
Those smokers only toked up a few times a month, but a more recent survey of people who smoked pot daily for up to 20 years found no evidence that smoking pot harmed their lungs.
With that caveat about research in mind, here are the medical benefits of marijuana.
Marijuana use can prevent epileptic seizures in rats, a 2003 study showed.
A professor gave marijuana extract and synthetic marijuana to epileptic rats. The drugs rid the rats of the seizures for about 10 hours. Cannabinoids like the active ingredients in marijuana, tetrahydrocannabinol (also known as THC), control seizures by binding to the brain cells responsible for controlling excitability and regulating relaxation.
The findings were published in the Journal of Pharmacology and Experimental Therapeutics.
During the research for his documentary interviewed the Figi family, who treats their daughter using a medical marijuana strain high in cannabidiol and low in THC.
There are at least two major active chemicals in marijuana that researchers think have medicinal applications (there are up to 79 known active compounds). Those two are cannabidiol (CBD) — which seems to impact the brain mostly without a high— and tetrahydrocannabinol (THC) — which has pain relieving (and other) properties.
The Figi family’s daughter, Charlotte, has Dravet Syndrome, which causes seizures and severe developmental delays.
According to the film, the drug has decreased her seizures from 300 a week to just one every seven days. Forty other children in the state are using the same strain of marijuana (which is high in CBD and low in THC) to treat their seizures — and it seems to be working.
The doctors who recommended this treatment say that the cannabidiol in the plant interacts with the brain cells to quiet the excessive activity in the brain that causes these seizures.
As Gutpa notes, a Florida hospital that specializes in the disorder, the American Academy of Pediatrics, and the Drug Enforcement agency don’t endorse marijuana as a treatment for Dravet or other seizure disorders.
CBD may also help prevent cancer from spreading, researchers at California Pacific Medical Center in San Francisco reported in 2007.
Cannabidiol stops cancer by turning off a gene called Id-1, the study, published in the journal Molecular Cancer Therapeutics, found. Cancer cells make more copies of this gene than non-cancerous cells, and it helps them spread through the body.
The researchers studied breast cancer cells in the lab that had high expression levels of Id-1 and treated them with cannabidiol. After treatment the cells had decreased Id-1 expression and were less aggressive spreaders. But beware: these are studies on cancer cells in the lab, not on cancer patients.
Other very preliminary studies on aggressive brain tumors in mice or cell cultures have shown that THC and CBD can slow or shrink tumors at the right dose, which is a great reason to do more research into figuring out that dose.
One 2014 study found that marijuana can significantly show the growth of the type of brain tumor associated with 80% of malignant brain cancer in people.
Medical marijuana users claim the drug helps relieve pain and suppress nausea — the two main reasons it’s often used to relieve the side effects of chemotherapy.
Researchers at Harvard Medical School suggested that that some of the drug’s benefits may actually be from reduced anxiety, which would improve the smoker’s mood and act as a sedative in low doses.
Published in the journal Molecular Pharmaceutics, found that THC, the active chemical in marijuana, slows the formation of amyloid plaques by blocking the enzyme in the brain that makes them. These plaques seem to be what kill brain cells and potentially cause Alzheimer’s.
A synthetic mixture of CBD and THC seem to preserve memory in a mouse model of Alzheimer’s disease. Another study suggested that in population-based studies, a THC-based prescription drug called dronabinol was able to reduce behavioral disturbances in dementia patients.
There are now over 175,000 patients in the Florida medical marijuana registry with many many more coming.
Yet marijuana’s official designation in the US as a Schedule 1 drug— something with “no currently accepted medical use” — means it has been pretty tough to study.
Despite that, a growing body of research and numerous anecdotal reports link cannabis with several health benefits, including pain relief and the potential to help with certain forms of epilepsy. In addition, researchers say there are many other ways marijuana might affect health that they want to better understand.
Along with several other recent studies, a massive report released last year by the National Academies of Sciences, Engineering, and Medicine helps sum up exactly what we know— and what we don’t — about the science of weed.
One of weed’s active ingredients, tetrahydrocannabinol, or THC, interacts with the brain’s reward system, the part primed to respond to things that make us feel good, like eating and sex.
When overexcited by drugs, the reward system creates feelings of euphoria. This is also why some studies have suggested that excessive marijuana use can be a problem for some people — the more often you trigger that euphoria, the less you may feel during other rewarding experiences. If you or someone close to your is interested in the benefits of medical cannabis, please visit a Florida medical marijuana doctors location near you today.
Within a few minutes of inhaling marijuana, your heart rate can increase by between 20 and 50 beats a minute. This can last anywhere from 20 minutes to three hours, according to the National Institute on Drug Abuse.
The report found insufficient evidence to support or refute the idea that cannabis might increase the overall risk of a heart attack. The same report, however, also found some limited evidence that smoking could be a trigger for a heart attack.
In August, a study published in the European Journal of Preventive Cardiology appeared to suggest that marijuana smokers face a threefold higher risk of dying from high blood pressure than people who have never smoked — but the study came with an important caveat: it defined a “marijuana user” as anyone who’d ever tried the drug.
Research suggests this is a poor assumption — and one that could have interfered with the study’s results. According to a recent survey, about 52% of Americans have tried cannabis at some point, yet only 14% used the drug at least once a month.
Other studies have also come to the opposite conclusion of the present study. According to the Mayo Clinic, using cannabis could result in decreased— not increased — blood pressure.
So while there’s probably a link between smoking marijuana and high blood pressure, there’s not enough research yet to say that one leads to the other.
Pot contains cannabidiol, or CBD, a chemical that is not responsible for getting you high but is thought to be responsible for many of marijuana’s therapeutic effects. Those benefits can include pain relief or potential treatment for certain kinds of childhood epilepsy.
The new report also found conclusive or substantial evidence — the most definitive levels — that cannabis can be an effective treatment for chronic pain, which could have to do with both CBD and THC. Pain is also “by far the most common” reason people request medical marijuana, according to the report.
One of the ways scientists think marijuana may help with pain is by reducing inflammation, a component of illnesses like rheumatoid arthritis.
A preliminary 2005 study of 58 patients with RA, roughly half of whom were given a placebo and roughly half of whom were given a cannabis-based medicine called Sativex, found “statistically significant improvements in pain on movement, pain at rest, quality of sleep” for patients on Sativex.
Other studies testing other cannabinoid products and inhaled marijuana have shown similar pain-relieving effects, according to the report.
A 2014 paper, for example, describes two studies of people with chronic Crohn’s. Half were given the drug and half got a placebo. That study showed a decrease in symptoms in 10 of 11 subjects using cannabis, compared with just four of 10 on the placebo. But when the researchers did a follow-up study using low-dose CBD, they saw no effect in the patients.
Researchers say that, for now, we need more research before we’ll know whether cannabis can help with these diseases.
Marijuana may throw off your balance, as it influences activity in the cerebellum and basal ganglia, two brain areas that help regulate balance, coordination, reaction time, and posture.
Feeling as if time is sped up or slowed down is one of the most commonly reported effects of using marijuana. A 2012 paper sought to draw some solid conclusions from studies on those anecdotal reports, but it was unable to do so.
“Even though 70% of time estimation studies report overestimation, the findings of time production and time reproduction studies remain inconclusive,” the paper said.
In a 1998 study that used magnetic resonance imaging (MRI) to focus on the brains of volunteers on THC, the authors noted that many had altered blood flow to the cerebellum, which most likely plays a role in our sense of time.
Limitations on what sort of marijuana research is allowed make it particularly difficult to study this sort of effect.
Since weed makes blood vessels expand, it can give you red eyes.
A case of the munchies is no figment of the imagination — both casual and heavy marijuana users tend to overeat when they smoke.
Marijuana may effectively flip a circuit in the brain that is normally responsible for quelling the appetite, triggering us to eat instead, according to a recent study of mice.
It all comes down to a special group of cells in the brain that are normally activated after we have eaten a big meal to tell us we’ve had enough. The psychoactive ingredient in weed appears to activate just one component of those appetite-suppressing cells, making us feel hungry rather than satisfied.
Marijuana can mess with your memory by changing the way your brain processes information, but scientists still aren’t sure exactly how this happens. Still, several studies suggest that weed interferes with short-term memory, and researchers tend to see more of these effects in inexperienced or infrequent users than in heavy, frequent users.
Unsurprisingly, these effects are most evident in the acute sense — immediately after use, when people are high.
Scientists can’t say for sure whether marijuana causes depression or depressed people are simply more likely to smoke. But one study from the Netherlands suggests that smoking weed could raise the risk of depression for young people who already have a special serotonin gene that could make them more vulnerable to depression.
Those findings are bolstered by the report, which found moderate evidence that cannabis use was linked to a small increased risk of depression.
The report also found substantial evidence of an increased risk among frequent marijuana users of developing schizophrenia — something that studies have shown is a particular concern for people at risk for schizophrenia in the first place.
Researchers think it’s possible that CBD might be a useful treatment for anxiety disorders, and that’s something that several institutions are currently trying to study.
The recent report suggested that evidence of a link between marijuana and an increased risk of most anxiety disorders was limited.
However, the authors wrote that there is moderate evidence that regular marijuana use is connected to an increased risk of social anxiety. As in other cases, it’s hard to know whether marijuana use causes that increase or people use marijuana because of an increased risk of social anxiety.
The THC content of marijuana across the US has tripled since 1995, according to a large recent study in which researchers reviewed close to 39,000 samples of cannabis. While THC levels hovered around 4%, on average, in 1995, they skyrocketed to roughly 12% in 2014.
Meanwhile, the CBD content in marijuana — the part that’s responsible for many of the drug’s therapeutic effects— has dropped, the researchers found, shifting the ratio of THC to CBD from 14:1 in 1995 to about 80:1 in 2014.
Still, tracking THC potency over time can be tricky. The older a weed sample gets, the more its THC appears to degrade. How it is stored matters too. These two barriers could be interfering somewhat with the metrics on pot’s potency.
In a recent study, scientists used MRI brain scans to get a better picture of the brains of adults who have smoked weed at least four times a week for years.
Compared to people who rarely or never used the drug, the long-term users tended to have a smaller orbitofrontal cortex, a brain region critical for processing emotions and making decisions. But they also had stronger cross-brain connections, which scientists think smokers may develop to compensate.
Still, the study doesn’t show that smoking pot caused certain regions of the brain to shrink; other studies suggest that having a smaller orbitofrontal cortex in the first place could make someone more likely to start smoking.
Most researchers agree that the people most susceptible to brain changes are those who begin using marijuana regularly during adolescence.
Some athletes, especially in certain endurance and adventure sports can boost their athletic performance. This may be because of anti-inflammatory or pain-relieving effects that make it easier to push through a long workout or recover from one.
At the same time, there are ways that marijuana could impair athletic performance, since it affects coordination and motivation, and dulls the body’s natural recovery process.
Without more research, it’s hard to know how marijuana affects athletic performance.