Study Reveals CBD May Help with Alzheimer’s Symptoms

A study from the Medical College of Georgia reveals CBD may be able to reduce brain plaque and improve cognition in Alzheimer's patients.

Calvin Chan, Ph.D. Updated on October 12, 2021

CBD Reduces Brain Plaques and Improves Cognition in Mice with Alzheimer’s

The first-ever study has shown that cannabidiol (CBD) can improve cognition and memory in mice with inherited Alzheimer’s.

Researchers from the Medical College of Georgia found that CBD can normalize levels of certain brain proteins affected by Alzheimer’s and reduce overall inflammation.

Alzheimer’s is the most common form of dementia and can occur in patients sporadically as they age or be inherited. Studies have shown that brain-damaged caused by Alzheimer’s can begin to trigger memory loss and other cognitive problems in patients as early as their 30s.

In mice with inherited Alzheimer’s, the study revealed that a two-week course of high levels of CBD significantly improved brain cognition and memory – to a level comparable to healthy mice.

The treatment also reduced the quantity of damaging beta-amyloid “plaques” in the brain, a major hallmark of Alzheimer’s disease.

CBD Improved Reduced Brain Plaques, Inflammation, and Cognition

Two key indicators of Alzheimer’s disease include the formation of beta-amyloid “plaques” and neurofibrillary tangles. Both are formed by the accumulation of certain – difficult to break down – brain proteins.

In healthy brains, these plaques can be cleared up by immune cells.

However, in Alzheimer’s, these immune cells fail to perform their debris-clearing roles and plaques begin to accumulate around neurons. This prevents neurons from effectively communicating with each other and can over time lead to brain damage and inflammation.

John Morgan, study co-author and a neurologist at the Medical College of Georgia explained that part of the reason immune cells become unable to clear up brain plaques may be due to a decline in two essential proteins, TREM2 and IL-33.

In the study, a two-week course of CBD significantly boosted TREM2 and IL-33 levels in brain immune cells. This also coincided with a drastic decline in the number of plaques as compared to mice treated with a placebo.

Babak Baban, an immunologist and study co-author said the CBD treatment also normalized levels of another brain protein, IL-33, which is usually atypically high in patients with Alzheimer’s and can trigger chronic inflammation.

To determine whether these changes improved Alzheimer’s symptoms in mice, the research team tested the animal’s ability to separate familiar objects they’ve seen in the past from novel objects.

In these tests, the mice given the CBD treatment had significantly improved physical coordination and memory – comparable to that of healthy mice.

CBD for Reducing Brain Plaque

CBD Study Opening Doors to Much Needed Treatment Options

The two current classes of treatments focus on improving memory and cognitive function by supplementing the brain with needed chemical signals or proteins to improve communication between neurons.

While these treatments can help slow brain deterioration, Morgan said that neither are unable to treat the underlying cause of Alzheimer’s.

“Right now, we have two classes of drugs to treat Alzheimer’s,” Morgan said. “But we have nothing that gets to the pathophysiology of the disease.”

The study’s success is now leading the research team to further explore how CBD can be used to improve treatment options for Alzheimer’s patients.

In the study, CBD was used to treat mice with late stages of Alzheimer’s, but now investigators are exploring whether CBD can be similarly effective with animals showing early stages of cognitive decline.

The study also focused on mice with an inherited form of Alzheimer’s similar to humans, but Baban said CBD should be at least equally effective in sporadic cases of Alzheimer’s as well.

Rather than relying on oral doses of CBD, the investigators are also looking into whether other types of delivery systems such as an inhaler can deliver more CBD directly to the brain where it’s needed.

While much more research remains to be done, the team says they may be looking forward to establishing a clinical trial soon.

Calvin Chan, Ph.D.

Calvin Chan is a researcher and medical writer from Edmonton, Canada. As a big science nerd, he loves reading and writing about everything science - from cannabis to dark matter and even alien life. Calvin has a PhD from the University of Alberta.