A new case of dementia is diagnosed about every four seconds. And while the overall incidence of Alzheimer’s disease and some other causes of dementia are dropping, the memory and cognitive problems caused by these disorders are likely to remain a major public health challenge for years to come.
The search continues for medications to stop or even reverse the progress of dementia—but cannabis may hold the key. Recent research on Alzheimer’s disease suggests that cannabinoids can act directly on the brain’s neurons. Cannabis has been shown to protect these neurons from the toxins and inflammation that kill brain cells and cause symptoms of dementia.
Dementia isn’t actually a disease. It’s the term given to a set of symptoms that can include:
Dementia symptoms can be related to a number of neurodegenerative diseases, cardiovascular problems and other kinds of health issues including:
Some causes of dementia are temporary and reversible, including vitamin deficiencies, medicine reactions or interactions, and thyroid conditions. Even severe depression can cause dementia.
But although there are multiple avenues for developing dementia, the outcome’s the same: the death of neurons in the brain. This leads to the many symptoms of largely irreversible cognitive and physical impairment.
Alzheimer’s disease is the most public face of the many causes of dementia, and a lot of research has focused on finding the causes of this memory-robbing disease. Scientists have learned that the brains of Alzheimer’s patients contain large amounts of a toxic protein called beta-amyloid 42. This protein clumps together to create plaque that accumulates between neurons and disrupts healthy functioning. Over time, neurons die, and the brain actually shrinks.
An added factor in the development of Alzheimer’s is the presence of neurofibrillary tangles. These are abnormal collections of another protein called tau inside the neurons themselves. These tangles also block transport systems between neurons so that they fail to communicate.
But what causes the buildup of beta-amyloid 42 and tau in the first place?
Many factors may play a role. People with Alzheimer’s disease often have other kinds of health problems, such as cardiovascular disease or diabetes. These disorders interfere with the movement of blood, oxygen and glucose to the brain, and this can contribute to the buildup of plaque and tangles.
That said, recent research suggests it’s actually chronic inflammation that could be the cause.
Studies reveal that inflammation can develop within neurons themselves when a certain kind of cell called microglia fails to do its job. Microglia could be called the brain’s housekeepers, responsible for destroying waste and toxins in the brain. But when these cells don’t work properly due to inflammation, poor blood flow, glucose buildup and other factors, toxic beta amyloid plaque can accumulate inside neurons, causing them to become impaired and eventually die.
A number of drugs have been developed to treat various symptoms of Alzheimer’s and other kinds of dementia with varying degrees of success. But recent studies show that cannabis may be better at protecting brain cells from inflammation and toxicity, thanks to its recognized effects on the body’s own endocannabinoid system (ECS).
The human body contains a rich network of cannabinoid receptors that respond both to natural cannabinoids produced in the body and to the very similar compounds produced by the cannabis plant. Researchers are still discovering new ways that the ECS affects overall health. Studies have shown that when cannabinoids from either source activate this system, it can trigger powerful responses that affect the:
With the exception of the brainstem, ECS receptors are abundant in most areas of the brain, including inside the neurons themselves. Multiple studies have shown that cannabinoid compounds found in various strains of the cannabis plant including tetrahydrocannabinol (THC) and cannabidiol (CBD), have anti-inflammatory and antioxidant properties. Combinations of THC and CBD may be able to help clear toxic beta amyloid plaque from neurons and reduce damage from inflammation in the brain.
For these reasons, cannabis is recognized as a potent neuroprotectant—meaning, it can shield vulnerable neurons in the brain from damage caused by events like traumatic brain injury and stroke. These same qualities can explain why cannabis can help reduce symptoms of dementia—or even prevent it from developing in the first place.
Because Alzheimer’s disease tops the list of dementia causes in the U.S., most research on cannabis for dementia has focused on that condition. But because of its anti-inflammatory and neuroprotective effects on brain cells, cannabis can also be helpful for symptoms that come from other causes like vascular dementia or the neurodegenerative disorder Parkinson’s disease.
A combination of THC and CBD seems to be most effective in reducing dementia symptoms, especially those related to anxiety and mood changes. Marijuana can also help with sleep disorders including “sundowning,” the late-afternoon restlessness and anxiety that strikes many Alzheimer’s disease sufferers.
Those with mild forms of cognitive impairment often choose to smoke or vape cannabis. But caregivers and family members can administer smoke-free consumption methods to people who have advanced problems with memory and self-care. These include marijuana tinctures and cannabis edibles. Patients can easily ingest precise cannabis doses when tinctures are added to their food or drink. And cannabis edibles, whether pre-made or homemade, mean the medicine’s effects last longer than with vaping or smoking.
Dementia has many causes, but the same result: damage to neurons that keep the brain functioning properly. Because it works with the body’s own ECS to protect and clear those vulnerable neurons, cannabis may be the key to relieving the symptoms of dementia at their source.
Photo credit: Val Vesa