In news that might be counterintuitive to the common experience of how weed affects memory, researchers have shown that marijuana could have potential in treating Alzheimer's disease. 

In particular, scientists from Salk Institute in San Diego found preliminary evidence that THC and other compounds in marijuana may promote the removal of amyloid beta, a toxic protein associated with Alzheimer's.

Alzheimer's is a terrible brain disease that causes memory loss, affects the ability of a person to carry on a daily life and leads to death. More than 5 million Americans and almost 44 million people worldwide suffer from this illness, which is also a common cause of dementia. The number of U.S. patients is expected to triple in the next 50 years.

The study was exploratory in nature and was conducted in lab-grown neurons. Yet it may point to new therapeutic avenues for combatting the disease.

David Shubert

Salk Professor David Schubert. Credit: Salk Institute

Professor Professor David Schubert of Salk Institute, the senior author of the study, explained:

"Although other studies have offered evidence that cannabinoids might be neuroprotective against the symptoms of Alzheimer's, we believe our study is the first to demonstrate that cannabinoids affect both inflammation and amyloid beta accumulation in nerve cells."

Accumulation of amyloid beta is a precursor to the disease's appearance. The protein causes plaques, although it is not yet clear what is their eventual role in the disease's progression.

So how did a compound within cannabis affect the illness?

By studying nerve cells which were made to produce large amounts of amyloid beta to mimic Alzheimer’s, the researchers concluded that the high amounts of the protein were linked to inflammation in the cells and a high rate of neuron death. But exposing the cells to THC reduced the amounts of the amyloid beta protein and got rid of the inflammation. This led the cells to continue living.

Antonio Currais, a researcher in Schubert's laboratory, had this to say:

"Inflammation within the brain is a major component of the damage associated with Alzheimer's disease, but it has always been assumed that this response was coming from immune-like cells in the brain, not the nerve cells themselves. When we were able to identify the molecular basis of the inflammatory response to amyloid beta, it became clear that THC-like compounds that the nerve cells make themselves may be involved in protecting the cells from dying."

The psychoactive effects of THC activate receptors within our brain cells, which leads to the removal of the dangerous protein.

The scientists point out that more studies are needed, and in particular, clinical trials that would use THC-like compounds for therapeutic purposes. You probably should wait before you start acting on the idea that smoking more pot will prevent the onset of Alzheimer’s.

When will these studies and trials take place? Dr. Shubert thinks that laws should change to reclassify the drug and allow for the full potential of marijuana-based treatments to be explored.

“This makes it almost impossible to do any science,” said Dr. Schubert to the Observer. “The government doesn’t want to fund clinical trials and drug companies can’t make a profit. Until the social structure changes and the laws change, it’s gonna be difficult to sort this out.”

No plant is illegal

You can read the study in Aging and Mechanisms of Disease here.