We released our new CBD research page today! It analyzes 112 peer-reviewed studies on CBD benefits, harms, and unknowns, making it the most comprehensive CBD page on the Internet.
If you find it informative, please share it with your friends who use CBD or cannabis!
CBD: Proven Health Benefits, Dosage, and more
Today is World Diabetes Day and, to mark the occasion, we’ve examined one of the most hotly debated diabetes treatments — low carb diets.
Click below to read our analysis of 37 RCTs examining the safety and effectiveness of low carb diets for people with type 2 diabetes.
About 90% of people who lose substantial weight regain most of it, according to various studies.
And that was before the COVID-19 pandemic! Now, regaining lost weight can seem almost inevitable.
A recent study analyzed people who lost weight, and explored factors linked to weight regain over 6 months and 24 months.
Don’t take these factors as absolutes though, just use them as guideposts. If you’re just eating less fish or fewer low-fat foods, that’s not going to torpedo your efforts. But if you find yourself violating most of the bigger tenets here (such as more sugary drinks and desserts plus less physical activity), it’s time to reassess!
The latest volume of NERD is out!
The types of articles you can find in the Nutrition Examination Research Digest include:
🔍 Deep Dives
Some studies are highly nuanced, and need to be analyzed in-depth. Others explore controversial topics, or use novel techniques that need explanation. These are a few of the many reasons to go extra deep into study analysis, and most of the studies analyzed in NERD get our full deep-dive treatment.
📝 Study Analysis
While some studies are important, they don’t quite need a Deep Dive to explore. We analyze these studies in an easy-to-digest question-based format to quickly give you the information you need to know without skipping out on some important details.
📚 NERD Minis
NERD minis distill information from recent reviews and guidelines in order to give you the essentials you need to know. We also occasionally cover some interesting non-trial studies that have hit the press recently.
🛑 NERD Nulls
One of the dirty secrets about scientific research is that studies finding no benefit or harm (null results), they are often not covered at all by the press.
So we make it our job to identify and quickly report null results every few months so you not only know what works, but also what doesn’t matter!
Every month, we find experts from across the health industry and pick their brains to get the lowdown on important health topics.
📰 NERD News
We keep you up to date on some of the latest happenings relevant to the world of nutrition and supplementation to boot! Want to get the rundown on new pharmaceuticals derived from nutritional ingredients? Or interesting goings on in the world of nutrition research? You’ll find it here.
🤔 Safety Spotlight
Supplements aren’t without their downsides. “Safety Spotlight” highlights recent safety concerns in the world of nutrition and supplementation.
We released our new CBD research page today! It analyzes 112 peer-reviewed studies on CBD benefits, harms, and unknowns, making it the most comprehensive…
Enter your email and we’ll keep you on top of the latest nutrition research, supplement myths, and more.
Why is CBD such a big deal? Two reasons. First, isolated CBD won’t get you “high”, unlike THC (the other main cannabinoid in cannabis). Second, isolated CBD has shown a ton of promise in animal research (anxiety, pain, inflammation, cancer, etc). Unfortunately, there are relatively few human trials as of 2019. And unregulated CBD often contains way lower or higher doses than the label states, sometimes even containing unlisted THC. Things are heating up though: in 2018, the FDA approved the first CBD pharmaceutical (Epidiolex ® ) for two rare types of epilepsy. Stay tuned to this page, as nearly 190 trials are underway!
Our evidence-based analysis on cbd features 119 unique references to scientific papers.
This page is regularly updated, to include the most recently available clinical trial evidence.
Each member of our research team is required to have no conflicts of interest, including with supplement manufacturers, food companies, and industry funders. The team includes nutrition researchers, registered dietitians, physicians, and pharmacists. We have a strict editorial process.
This page features 119 references. All factual claims are followed by specifically-applicable references. Click here to see the full set of references for this page.
Primary information, health benefits, side effects, usage, and other important details
What is CBD?
CBD (cannabidiol) is the second most abundant cannabinoid in cannabis, after THC (tetrahydrocannabinol). Andre CM, Hausman JF, Guerriero G. Cannabis sativa: The Plant of the Thousand and One Molecules.
Front Plant Sci (2016)’ data-persistent=”true”> Isolated CBD is typically used medicinally, not recreationally, with the four most commonly targeted conditions being pain, anxiety, depression, and sleep disorders. Corroon J, Phillips JA. A Cross-Sectional Study of Cannabidiol Users.
Is CBD legal?
Let’s just say . it’s complicated. CBD products that are derived from hemp, with a low-to-zero percentage of THC (below 0.3%), are currently in a legal gray area in the US.
A quick bit of history: The Farm Act was passed in December of 2018, and it legalized hemp (the source of CBD).  CBD advocates rejoiced – CBD supplements were already commonplace in 2018, but now in 2019 they’re pretty much everwhere. Some estimates suggest up to 7% of adults have used CBD, and there were up to $2 billion in sales in 2018 (projected to rise dramatically in the next couple years).
In December of 2018 though, the FDA stated that CBD cannot be marketed as a supplement without FDA approval, but in April of 2019, the FDA was taking public comments to formulate a revised position.  Currently, non-pharmaceutical CBD is technically only legal under very specific conditions, such as when the source hemp was produced in a manner consistent with the Farm Bill, and by a licensed grower. Complicating matters further: the DEA and individual states can have different legal perspectives on CBD. Clarification on CBD legality should come within the first half of 2019.
As far as 100% unquestionably legal CBD goes, the liquid CBD medication Epidiolex was recently FDA-approved in 2018. Note that it’s not the first cannabis extract drug. Nabiximols (brand name Sativex) is a cannabis extract spray with a nearly 1:1 ratio of THC:CBD, and it was approved as a drug in the UK in 2010 (but has not been approved in the US). Due to the THC content, it has a different side effect profile than Epidiolex, such as dizziness and disorientation. Russo M, et al. Should we care about sativex-induced neurobehavioral effects? A 6-month follow-up study.
Eur Rev Med Pharmacol Sci (2016)’ data-persistent=”true”> However, due to the THC, it may have benefits for a wider variety of conditions than CBD alone (due to the “entourage effect”), such as for spasticity from multiple sclerosis. Sastre-Garriga J, et al. THC and CBD oromucosal spray (Sativex®) in the management of spasticity associated with multiple sclerosis.
What are CBD’s potential benefits?
Before protesting, “Hey, why doesn’t your Scientific Research section cover XYZ mouse study showing CBD benefits?”, take note that mice are not human. In fact, the same exact dose of CBD in a mouse versus a human will be more bioavailable in the mouse, leading to larger effects. Deiana S, et al. Plasma and brain pharmacokinetic profile of cannabidiol (CBD), cannabidivarine (CBDV), Δ⁹-tetrahydrocannabivarin (THCV) and cannabigerol (CBG) in rats and mice following oral and intraperitoneal administration and CBD action on obsessive-compulsive behaviour.
Psychopharmacology (Berl) (2012)’ data-persistent=”true”> That’s besides the bevy of other reasons that animal studies often don’t translate to humans, such as different metabolic pathways in animals, lab conditions differing from free-living human conditions, etc. Bracken MB. Why animal studies are often poor predictors of human reactions to exposure.
Is CBD dangerous?
In small amounts, probably not for most people. In large amounts over time . well, read on to get a gist of the risks.
The most notable (acute) drawbacks of cannabis consumption don’t apply to isolated CBD: a possible mind-altered state involving one or more of impaired memory, altered judgment, and impaired coordination. Iffland K, Grotenhermen F. An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical Data and Relevant Animal Studies.
Yet CBD is not without potential detriment. The long-term use of isolated CBD isn’t well researched in humans, so potential harms may be possible. For example, CBD and cannabis in general has been touted as a potential cancer treatment, Śledziński P, et al. The current state and future perspectives of cannabinoids in cancer biology.
Oncotarget (2016)’ data-persistent=”true”> CBD studies are typically very short term, and side effects are captured as part of studies exploring potential benefits. It would take months- or years-long studies to assess long-term risk of chronic ingestion on specific body systems.
Despite this, CBD appears to be much safer than many other treatments aimed at chronic pain and anxiety, as well as drugs used for recreational use. In fact, the World Health Organization concluded in a review: “to date, there is no evidence of recreational use of CBD or any public health-related problems associated with the use of pure CBD”. WHO – CANNABIDIOL Critical Review Report,.
How exactly does CBD work?
The myriad ways in which it works are not fully understood, but do not appear to center on the CB1 and CB2 receptors that THC acts on. Those receptors are part of the relatively newly-discovered endocannabinoid system, first described in 1992, Devane WA, et al. Isolation and structure of a brain constituent that binds to the cannabinoid receptor.
Science (1992)’ data-persistent=”true”> and increasingly found to be important to human health and well-being through maintaining homeostasis (balance) in various aspects of physiology. Mouslech Z, Valla V. Endocannabinoid system: An overview of its potential in current medical practice.
Curr Clin Pharmacol (2016)’ data-persistent=”true”> CBD actually opposes the action of THC at the CB1 receptor (and certain other receptors as well), which can help counter THC’s (potential) worsening of cognition, memory, psychosis, and other effects. Thomas A, et al. Cannabidiol displays unexpectedly high potency as an antagonist of CB1 and CB2 receptor agonists in vitro.
Anywho, back to CBD’s main effects. It appears to impact a variety of other receptors in the body, including an important receptor involved in pain and stress response, called TRPV1. Jara-Oseguera A, Simon SA, Rosenbaum T. TRPV1: on the road to pain relief.
Eur Neuropsychopharmacol (2009)’ data-persistent=”true”> Other receptors that CBD impacts include GPR55, 5HTI-alpha, and adenosine A2A, which variously can help with inflammation, pain, anxiety, and even potentially cancer. Ryberg E, et al. The orphan receptor GPR55 is a novel cannabinoid receptor.
There’s a big catch though! CBD often seems to work better with THC (basically, in the typically consumed or inhaled form of medical cannabis, rather than as isolated CBD). This is often referred to as the “entourage effect” – that a single ingredient might, maybe do a little something, but you need the whole crew of compounds in the plant to have full efficacy. Russo EB. The Case for the Entourage Effect and Conventional Breeding of Clinical Cannabis: No “Strain,” No Gain.
Front Plant Sci (2019)’ data-persistent=”true”> The problem here is that the whole crew can make you high, which is not typically desired in continuously-taken medications, and may even increase the risk of psychosis with longer term use. Murray RM, et al. Traditional marijuana, high-potency cannabis and synthetic cannabinoids: increasing risk for psychosis.
Why is CBD such a big deal? Two reasons. First, isolated CBD won’t get you "high", unlike THC (the other main cannabinoid in cannabis). Second, isolated CBD has shown a ton of promise in animal research (anxiety, pain, inflammation, cancer, etc). Unfortunately, there are relatively few human trials as of 2019. And unregulated CBD often contains way lower or higher doses than the label states, sometimes even containing unlisted THC. Things are heating up though: in 2018, the FDA approved the first CBD pharmaceutical (Epidiolex®) for two rare types of epilepsy. Stay tuned to this page, as nearly 190 trials are underway!