Compounds in marijuana may be able to help symptoms of Alzheimer’s disease.
Memory gradually declines with age for everyone. But for those with Alzheimer’s disease, memory loss can be so severe that they can lose the ability to recognize their loved ones.
Areas of the brain responsible for memory are affected in Alzheimer’s, and these areas are highly regulated by the endocannabinoid system. This system is activated by compounds in marijuana known as cannabinoids.
Cannabinoids, such as THC and CBD, also have anti-inflammatory and neuroprotective effects that may help slow the progression of Alzheimer’s disease.
Here, we discuss the merits of marijuana as a potential treatment for Alzheimer’s disease.
What is Alzheimer’s Disease?
Alzheimer’s disease is a neurodegenerative condition that mostly occurs in the elderly. The disease is progressive, meaning symptoms tend to worsen over time.
Neurodegeneration is the process of losing brain cells over time. It is not known what causes neurodegeneration in Alzheimer’s.
The most well-known symptom of Alzheimer’s is dementia. Initial symptoms of dementia include problems with memory, but gradually expand into other symptoms like language impairments and behavioural changes.
The progression of Alzheimer’s is associated with the formation of plaques in the brain. These plaques form when a compound known as beta-amyloid is released from brain cells into grey matter.
These plaques actually form in the brains of healthy older adults too, but genetic differences in patients with Alzheimer’s cause a significantly higher number of plaques to form.
Can Marijuana Help Alzheimer’s Disease?
Overall, there is not much evidence on whether marijuana can treat Alzheimer’s, but early reports are promising.
There is preliminary evidence that cannabinoids have neuroprotective and anti-inflammatory effects. Because of this, some researchers believe that marijuana may help with Alzheimer’s.
Researchers have investigated the role of the endocannabinoid system in Alzheimer’s disease. The endocannabinoid system is crucial in regulating memory, and scientists believe it may be affected in Alzheimer’s. Since marijuana stimulates the endocannabinoid system, it may be able to offer some benefits.
During the early stages of Alzheimer’s, the endocannabinoid system is blocked by the formation of beta-amyloid plaques. This disruption of the endocannabinoid system is believed to be partially responsible for the early symptoms of memory impairments.
Other evidence has found that cannabinoids can help protect brain cells from damage and prevent cognitive impairments in animal models of Alzheimer’s. This has led to an interest in THC as a potential treatment option. THC is thought to exert its neuroprotective effects by activating CB1 receptors.
Benefits of Marijuana For Alzheimer’s Disease
Cannabinoids reduce inflammation
Inflammation in the brain leads to damage in neurons and is believed to contribute to neurodegeneration in Alzheimer’s.
A 2009 study found that cannabinoids can help regulate inflammation in the brain. The researchers concluded that cannabinoids could someday be used to reduce inflammation in neurodegenerative conditions like Alzheimer’s disease.
Marijuana improves memory
The most well-known symptom of Alzheimer’s disease is the loss of memory. Patients slowly lose the ability to recognize their loved ones, their surroundings, and how to communicate.
A 2012 study showed cannabinoids can help protect brain cells from the beta-amyloid plaques seen in Alzheimer’s disease.
The study used a synthetic cannabinoid called WIN55212-2, which acts on cannabinoid receptors. The researchers observed that the cannabinoid improved memory in a rodent model of Alzheimer’s.
THC is neuroprotective
Like other neurodegenerative disorders, protecting the brain from further damage is an important element in treating Alzheimer’s. Cannabinoids are known to have neuroprotective properties, and researchers are investigating their potential in Alzheimer’s.
A 2016 study used human nerve cells to investigate the effects of THC on beta-amyloid levels.
The researchers found that THC improved the removal of beta-amyloid from the cells. THC also reduced inflammation and protected the neurons from damage. This evidence suggests that THC might be able to reduce the severity of Alzheimer’s disease in humans.
A 2006 study showed that THC might be able to block acetylcholinesterase (AChE), an enzyme that contributes to beta-amyloid plaque production.
Marijuana improves behavioural issues
As Alzheimer’s progresses, symptoms other than memory deficits begin to develop. During the late stages of the disease, behavioural problems such as irritability and aggression become more prevalent.
In a 1997 study, researchers found that THC could reduce behavioural disturbances in Alzheimer’s disease, and improved appetite in patients. The researchers noted that the effects of THC lasted into the placebo period, indicating that THC had long-term benefits.
Another human trial on the impact of THC in Alzheimer’s disease found that marijuana-infused oils could improve behavioural issues.
The study involved 11 patients, and was published in 2016 by researchers in Israel. Delusions, aggression, irritability, apathy, and sleep were significantly improved when the cannabis oil was added to the patients’ treatment regimens.
CBD and Alzheimer’s Disease
When discussing marijuana in a medical context, it’s important to consider the differences between THC and CBD. Despite coming from the same plant, these cannabinoids behave very differently in the body and offer unique therapeutic effects.
Unlike THC, CBD does not have any psychoactive effects. This can be very helpful for patients who can’t tolerate the psychoactive side effects of THC.
CBD can also reduce symptoms of psychosis and anxiety, suggesting it may be a better alternative for Alzheimer’s patients suffering from psychiatric symptoms. THC, on the other hand, may exacerbate these symptoms.
CBD might improve memory deficits in Alzheimer’s disease. A 2014 study published in the journal Psychopharmacology found that CBD could reverse cognitive deficits in an animal model of Alzheimer’s when given on a regular basis.
In a 2017 study, CBD was found to reduce the levels of proteins that contribute to beta-amyloid plaque production.
CBD may also help promote growth of new brain cells that have died off because of beta-amyloid plaques. A 2011 study found that CBD increased neurogenesis in the hippocampus, an area that regulates memory and is damaged in Alzheimer’s disease.
In a 2017 review of the pre-clinical evidence for CBD as a treatment for Alzheimer’s, researchers found that CBD had anti-inflammatory and neuroprotective effects. However, these effects still require confirmation from clinical trials to determine whether the results are relevant to humans.
While preliminary research is promising, human trials are needed to determine if marijuana can be an effective treatment for Alzheimer’s disease.
Both THC and CBD have shown potential to reduce inflammation and protect neurons from damage by beta-amyloid plaques. In addition, CBD may promote the growth of new brain cells, and has fewer side effects than THC.
While there is not a lot of human research, some studies have found that THC can reduce behavioural disturbances in Alzheimer’s patients.
Based on early findings, some scientists believe marijuana has the potential to treat Alzheimer’s disease.