CBD has been a fad for a few years now, and for good reason. Not only are anecdotal stories of its benefits compelling (we all have friends who swear by it!), but studies also demonstrate impressive actions on a number of different systems.

Most of my patients who ask me about adding in CBD do so for its effects on anxiety, sleep, and pain. Here’s what the data says. 

CBD vs THC (Tetrahydrocannabinol)

There are two cannabinoid receptors: CB1 and CB2. THC is the component of marijuana which causes psychotropic effects and has a higher affinity for the CB1 receptors, found primarily in the brain and spinal cord. CBD has an affinity for the CB2 receptors, found mostly in immune and blood cells. It does not cause the psychotropic effects traditionally associated with marijuana. 

CBD also helps to block both the breakdown and the reuptake of anandamide, the body’s most prevalent naturally produced cannabinoid (aka endocannabinoid). This is probably plays a large role in its effects as well. 

CBD, Neurotransmitters, and Neuroprotection

CBD’s effects upon anxiety and depression probably stem from its modulating effects upon serotonin receptors. Those with depression tend to have a low number and low function of these receptors.

Stimulation of these receptors also produces brain-derived neurotrophic factor (BDNF), which helps with not only memory and cognition, but is also neuroprotective and helps form new connections between synapses. CBD’s ability to boost BDNF may be part of the reason why CBD reduces inflammation in the brain. As brain inflammation can also cause depression, this is another mechanism by which it helps balance mood.

CBD, Alzheimer’s, and Epilepsy

Given its neuroprotective properties, BDNF is not surprisingly low in those with Alzheimer’s. CBD also prevents neuronal death due to the beta amyloid plaques found in Alzheimer’s, and helps the hippocampus (the part of the brain responsible for formation of new memories) regenerate.

Endocannabinoids are also important in suppressing seizure activity, making CBD a good adjunctive therapy for epilepsy as well.

CBD, Inflammation, and Pain

The second most common reason people choose to try CBD is for pain. It works by decreasing inflammatory cytokines.

How it does this: adenosine is the core of ATP, your body’s energy currency. Your body breaks down ATP in the course of a day, and adenosine accumulates, eventually telling your brain (via adenosine receptors) that it’s time to sleep. At the same time, immune cells can take up adenosine and produce inflammatory cytokines (which is part of the reason why fibromyalgia, so often associated with insufficient sleep, causes pain.) Only deep sleep adequately recycles adenosine back into ATP; caffeine suppresses adenosine receptors, but only temporarily. CBD, meanwhile, decreases adenosine uptake into immune cells, thereby decreasing release of cytokines.

On the flip side, CBD can increase allergic responses, as there are two sides to the immune system (Th1 and Th2). Suppress one side, and you can cause a flare in the other.

CBD and Bones

CBD is also a useful treatment for osteoporosis, as it helps to both stop bone loss and stimulate new bone production.

CBD and Cancer

CBD has also been shown to be a useful adjunctive treatment for cancer. It boosts the body’s own natural cancer defenses, including production of reactive oxygen species (ROS).

It also inhibits cancer cells’ defense against chemotherapy. A protein called breast cancer resistance protein (BCRP) helps cancer cells flush out foreign compounds, such as chemo. CBD has been shown to suppress BCRP, thus rendering chemo more effective.

CBD Contraindicated In Pregnancy

While the BCRP suppression effects of CBD are helpful during cancer treatment, they can be dangerous during pregnancy. This is because the placenta uses BCRP to protect the baby from toxic foreign compounds. Suppression of it can lead to toxic accumulation, and can harm the baby. 

The Upshot

CBD has no psychotropic effects, and for the most part it’s very safe to try—provided it comes from a reputable source. This is especially important because purity is not well regulated currently, and therefore it may contain solvent or heavy metal contamination. If you choose to try it, look for a company that makes this purity data available.