Marijuana shows promise as Alzheimer's treatment say Salk researchers

Treatment for Alzheimer's may soon come from an unexpected source: a marijuana plant. Researchers from the Salk Institute in California testing the effects of the cannabis compound THC on lab-grown neurons found that it not only broke down amyloid-beta proteins that cause the plaque build-up associated with Alzheimer's — but it reduced inflammation in the cells.

Cell inflammation hampers communication between neurons.

"Although other studies have offered evidence that cannabinoids might be neuro-protective 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," Salk Professor David Schubert, the senior author of the study, said in a statement.

The study also demonstrated a stronger link between protein build-up and the inflammation of the neurons than previously understood. Past theories speculated that other immune-like cells became inflamed, not the neurons themselves.

The Salk researchers believe that the THC was able to reduce the protein build-up and inflammation by working in the brain's endocannabinoid receptors, which occur naturally in the body. Scientists already knew that exercise engages these same receptors, and that physical activity can slow the progression of Alzheimer's disease.

The researchers warned that much more work needs to be done, including in clinical trials on humans, before THC could be used as a treatment for Alzheimer's.