A recent University College London (UCL) study found that a single dose of cannabidiol (CBD) helped increase cerebral blood flow in a region of the brain associated with emotion and memory processing called the hippocampus. The trial tested only one dose, so the effects of repeated dosing are unknown as of yet. However, the team believes their findings could facilitate better target therapies using the cannabis compound for conditions that affect memory, such as post-traumatic stress disorder (PTSD) and Alzheimer’s disease.
CBD is a crucial compound in cannabis – one of over 100 different cannabinoids found in the plant. Tetrahydrocannabinol (THC) is another critical compound – the one associated with the plant’s psychoactive euphoric effects. While THC may cause forgetfulness, CBD is not the same and even has been found to bestow several positive health outcomes.
In this study, the researchers wanted to inspect the influences of CBD on blood flow in the brain – specifically in all the regions involved with memory processing. Previous research findings suggest that better memory performance may be linked to higher resting hippocampal blood flow.
Lead author, Dr. Michael Bloomfield (UCL Psychiatry) said:
Cannabidiol is one of the main constituents of cannabis and is gaining interest for its therapeutic potential. There is evidence that CBD may help reduce symptoms of psychosis and anxiety. There is some evidence to suggest that CBD may improve memory function. Additionally, CBD changes how the brain processes emotional memories, which could help to explain its reputed therapeutic effects in PTSD and other psychiatric disorders. However, the precise mechanisms underlying the effects of CBD on memory are unclear.
For the trial, fifteen healthy non-cannabis users were recruited. They were given a 600mg capsule of either CBD or a placebo. Nobody knew which they were getting. After they dosed, the researchers conducted brain scans to measure blood flow to the hippocampus. They used a technique called ‘arterial spin labeling,’ which is a magnetic resonance imaging (MRI) that measures alterations in the blood oxygen levels.
The results showed a significant increase in hippocampal blood flow, but none in any other brain regions of the medial temporal lobe. However, increases in blood flow were also observed in the area associated with planning and decision making called the orbitofrontal cortex.
Broomfield said:
To our knowledge, this is the first study to find that CBD increases blood flow to key regions involved in memory processing, particularly the hippocampus. This supports the view that CBD has region-specific blood flow effects in the human brain, which has previously been disputed.
If replicated, these results could lead to further research across a range of conditions characterized by changes in how the brain processes memories, including Alzheimer’s disease, where there are defects in the control of blood control flow, along with schizophrenia and post-traumatic stress disorder.
The researchers also had the participants take tests to gauge their memory task performance, but none of them showed any improvements. Therefore, CBD may not be an acute memory-boosting compound, but it could still help treat neurological conditions related to region-specific blood flow abnormalities. Further studies will be needed to know more, primarily since the study examined only a single dose, and the effects may be completely different from repeated CBD dosing.
Aside from this, CBD has also shown promise as an antibiotic against many gram-positive bacteria, including resistant superbugs. And Colorado State University found the compound helps slow aggressive human and canine brain cancer cells in the lab.
