Products infused with cannabidiol (CBD) are popping up everywhere from coffee shops to corner markets, promising to ease anxiety, soothe eczema, and even treat diabetes. But how many of these claims are grounded in evidence, and how many are pure hype?
Here's what researchers and experts say about the promise, and the potential pitfalls, of the CBD boom.
About the CBD boom
CBD is the second most abundant component of the cannabis plant after tetrahydrocannabinol (THC). Unlike THC, CBD does not get users high, but there's some limited evidence suggesting that it may have anti-anxiety, anticonvulsant, and anti-inflammatory effects.
That early-stage evidence—combined with the recent popularity anti-anxiety products and the growing movement to legalize marijuana—has given rise to a big CBD industry, Vox reports.
In fact, CBD products raked in $350 million last year. Among the products and services on offer are a $700 CBD couples massage in Philadelphia, a range of topical creams and oils in beauty and convenience stores, and CBD-infused snacks such as cookies and ice cream, Vox reports.
Why experts are skeptical
But experts warn that these products are unregulated, and very little is known about CBD's medicinal effects or potential hazards.
According to Vox, CBD research has been restricted because—at least for now—the Drug Enforcement Administration classifies it as an illegal substance, and researchers in the United States are required to have a license to possess and study the compound.
Orrin Devinsky, director of the NYU Langone Comprehensive Epilepsy Center, said, "Does [CBD] help people with eczema, rheumatoid arthritis or ulcerative colitis? We don't know. There is a good theoretical basis, but the studies have not been done."
What we do (and don't) know about CBD
So what do we actually know about the health effects of CBD?
To date, FDA has approved one drug containing a highly purified form of CBD, Epidiolex, based on clinical trials that showed the drug reduced seizures in children with two rare forms of epilepsy. From that clinical trial, researchers also know CBD can trigger adverse side effects, such as diarrhea and fatigue, the New York Times reports. Patients who participated in the trials had higher rates of infection, sleep problems, and depressed appetite, according to the New York Times.
Beyond that, it's generally accepted that CBD is not habit-forming, and it doesn't produce the same high one gets from marijuana with THC. Further, animal studies have found that CBD might have anti-inflammatory effects that can treat chronic pain or inflammatory diseases in animals—but "whether that translates into improving human health is unknown," Devinsky said.
There's also limited research that indicates CBD can help treat psychological disorders. Just last year, research performed by European scientists found that patients with schizophrenia who took 1,000 milligrams of CBD with their other antipsychotic medications had fewer hallucinations than patients who did not take CBD. However, the results of a similar study did not reveal similar benefits.
Michael Van Ameringen, director of an anxiety research center in Ontario, said while some companies indicate that CBD can treat some mental health conditions like anxiety disorders, "there actually really is very, very little scientific evidence to support its use as a treatment for anxiety at this point."
What about the risks?
For its part, FDA considers CBD a drug, and it has issued warning letters to companies marketing the compound as a dietary supplement or selling it in foods or drinks.
There is also a significant risk that CBD could interfere with other medications patients might be taking, according to Sumner Burstein, a professor emeritus of biochemistry and molecular pharmacology at the University of Massachusetts Medical School.
Further, experts note that most of the CBD products available on the market are not regulated by FDA. Dustin Lee, an assistant professor in psychiatry and behavioral sciences at Johns Hopkins University, said, "It might be available at the local 7-11 in Pennsylvania, but any product you get on the market is not federally regulated by the FDA, so the purity and safety and quality are questionable.
Another issue is how CBD is ingested. Some of the most popular CBD products on the market, such as CBD oil, can be added to food or beverages, but experts say it would need to be consumed at a very high dose to have any effect because CBD oil has high fat solubility.
What's next for CBD research?
Much more may be known about CBD soon, in part because research restrictions are expected to be eased after the 2018 farm bill legalized industrial hemp nationwide.
Numerous studies are underway to determine the effectiveness of CBD in curb substance misuse and help with tobacco cessation, enhance cancer treatment, or manage the inflammatory symptoms of disorders like Crohn's disease, according to the New York Times.
Yasmin Hurd, a professor at the Icahn School of Medicine and the director of the Addiction Institute at Mount Sinai, said scientists and consumers need to "do the research" before trusting CBD.
"It's crazy that this substance is being consumed by everybody, yet we still don't know the mechanism of action," she said. "People are making it out to be a nirvana kind of drug, and that's a problem. One compound cannot cure everything" (Rabin, New York Times, 2/25; Nosowitz, Vox, 1/17).
Cheat sheet series: Evidence-based medicine 101
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- Evidence-based practice (EBP)
- Observational studies
- Randomized control trials (RCT's)
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