Claims about CBD’s purported healing powers have been so exaggerated that it’s no surprise that a CBD manufacturer was warned in 2020 by the New York Attorney General for claiming the molecule can fight COVID-19. There are no credible animal or human studies showing that CBD has an effect on SARS-CoV-2 or the course of COVID-19 infection.
As Professor and President from the Department of Pharmacy Practice at the University of Connecticut, I have investigated many claims of vitamin cures for various diseases over the decades, including CBD.
Antioxidant vitamin cocktails were once considered the new stars of the nutrition world. The cocktails, with vitamin E, beta-carotene and vitamin C, are said to have reduced the risk of heart disease, stroke and cancer. This story – derived from single cell and small animal studies – was captivating. Imagine taking a vitamin pill to stop free radical damage or prevent your arteries from hardening.
The next step was soy and resveratrol, the so-called superfoods that may reduce heart disease and cancer rates; then Coenzyme Q10, touted to prevent statin-induced muscle damage. All fell out of favor when definitive studies were conducted.
But the CBD hype is in a class of its own, as misinformation about this cannabis-derived molecule exploded after a drug containing cannabidiol – or CBD — received Food and Drug Administration approval in 2018 — for the treatment of seizures associated with two rare forms of epilepsy.
How strong is CBD data?
On behalf of the Journal of Clinical Pharmacology, in 2020 carried out an examination who assessed the evidence supporting the use of CBD.
There is strong evidence that CBD can benefit some people. CBD can prevent seizures in people with two rare diseases, Lennox Gestaut and Dravet syndrome. CBD consistently shows benefits when used before an anxiety-provoking event, like speaking in public(although not as effective as clonazepam, a drug indicated by the FDA for performance anxiety).
Limited studies show promising initial results for other conditions, although more research is needed. CBD could help inflammation joints or skin, sleep disturbances, chronic anxiety, psychosis and behavioral problems associated with Fragile X syndrome. But natural alternatives already exist that offer much more evidence for some of these benefits: Melatonin sleep aid, kava for chronic anxiety and curcumin turmeric extract for general inflammation or fatty liver.
CBD has been shown to be ineffective in treating symptoms of Parkinson’s disease and Crohn’s disease. Data on the treatment of pain and muscle spasms are poor. As for preventing cancer, rosacea, or the dozens of other things it’s supposed to fix, that’s pure speculation.
The risks of CBD
CBD is a drug. The FDA allows it to be sold as a cosmetic and prescription product, and you can also buy it without a prescription. But just because it’s in a lot of things (seltzer water, cupcakes, and beer, to name a few) doesn’t mean it’s risk-free. In the greatest assessment, high doses of CBD caused mild liver damage in 17% of people who took it. Serious or irreversible damage would have occurred if the researchers had not prevented the subjects from taking more. If you take CBD at home, without medical supervision, you will not be aware of liver damage until it is acute.
There are also drug interactions. Add CBD to other medications you take and it could produce unexpected side effects or make those medications less effective. I wouldn’t take CBD without consulting my doctor or pharmacist to make sure there were no risky drug interactions.
Because CBD is a seizure medication, the FDA fears it may not promote suicidal thoughts, like some other antiepileptic drugs do. Although there is no data to support this concern, CBD has not been studied long term. The most common side effects of CBD are drowsiness and diarrhea, which occur in a third of users, and vomiting and fever, which occur in 15%.
You take additional risks if the CBD product is not certified by an external laboratory. Without it, bacterial, fungal, or heavy metal contamination of CBD becomes more likely, as does mixing CBD with synthetic drugs. Many independent reviews already show that many products do not contain the amount of CBD they claim; some provide much less.
Conversely, some of the products contain more than the legal limit of THC. This puts you at risk of arrest for possession of marijuana. There are other unfortunate scenarios as well: you may have used a sub-potent product and taken 500mg to get the desired benefits. Then, after switching to a higher quality product, you take the same 500mg and accidentally overdose.
CBD is neither a miracle nor snake oil. So far, the evidence — or lack thereof, for most conditions — suggests the risks may outweigh the benefits.
Eating a balanced diet, exercising regularly, getting enough sleep, maintaining a healthy weight and managing stress are the foundations of good health. Nowhere is there a recommendation to adopt every health mode that comes along. But people are psychologically attracted to health modes because they’re new, they seem plausible (at least on the surface), and they’re easy to use. In addition, there is the bandwagon effect: no one wants to be left behind.
But it is a mistake to believe that the studies of cells in a laboratory are directly applicable to man. It’s a mistake to believe customer testimonials in television commercials. Besides, it is a mistake to believe much of the content of these advertisements. Some do false statementssome are selective in the information they provide and others suppress negative product information.
[You need to understand the coronavirus pandemic, and we can help. Read The Conversation’s newsletter.]
