CBD may slow Alzheimer's by calming the brain's immune response, mouse study finds
A new study published in Science Daily shows that cannabidiol (CBD) can reduce neuroinflammation by calming the brain's immune response in mouse models of Alzheimer's disease. In the study conducted at Auburn University in collaboration with the Salk Institute, mice that received inhaled CBD showed reduced activity in brain immune cells known as microglia. When chronically activated, these cells can lead to brain tissue damage.
The study's lead author, Auburn University Medical School neuroscience professor Dr. Vishnu Suppiramaniam, said, 'The role CBD might play in Alzheimer's disease has been debated for years. This study documents in detail, for the first time, a mechanism that targets the brain's immune response.' The study was published on 27 May in the Journal of Alzheimer's Disease.
According to the study, when 5xFAD model mice were given CBD twice daily for five weeks, brain amyloid plaque density decreased by 18 percent. At the same time, a 24 percent drop was observed in inflammation markers such as IL-6 and TNF-alpha. These markers play a key role in the progression of Alzheimer's disease.
Nature Neurology editor Sarah-Maria Fendt commented to Science Daily, 'Despite the small sample, the study is important for mechanism inference. The next step is larger animal studies; moving to human studies will require an additional 3-5 year process.' Fendt said that phase 1 and phase 2 human trials are mandatory for the clinical importance of the study to be assessed.
Salk Institute neuroscientist Roberto Malinow, a co-author of the study, told Bloomberg, 'The effect of CBD on neuroinflammation may also be valuable in other neurodegenerative diseases. We are laying the groundwork for Parkinson's and multiple sclerosis studies.' Malinow said the cost of clinical trials would exceed 60 million dollars in the next three years.
Alzheimer's Association Science Director Maria Carrillo described the study as 'promising but early.' Carrillo said, 'Clinical trials under medical supervision are essential for definitive evidence on whether CBD is effective for patients. We advise our patients not to use CBD based on their own decisions.' Roughly 6.7 million Americans have an Alzheimer's diagnosis.
The U.S. Food and Drug Administration (FDA) has approved only one CBD product since 2018, the epilepsy drug Epidiolex. Other CBD products fall outside federal regulation but make up a 6.2 billion dollar industry in the U.S. market. An FDA spokesperson told Science Daily that for CBD products to be considered a treatment for Alzheimer's, 'the adequacy of clinical evidence would need to be comprehensively assessed.'
An additional finding from the study is that CBD is only effective at high doses. At low doses, the effect was negligible. This means that people using unregulated products may not achieve adequate protection for Alzheimer's. The study identified the effective dose as 50 mg per inhalation.
In terms of economic impact, Alzheimer's disease is estimated to cost the U.S. roughly 470 billion dollars annually. By 2050 that figure is projected to reach 1.1 trillion dollars. A CBD-based treatment could potentially be cost-competitive with current cholinesterase inhibitors.
This article is a scientific research news report; it should not be read as medical advice on Alzheimer's disease, CBD use or personal medical decision making. For your medical decisions, please consult a licensed medical specialist.