Tetrahydrocannabinol (THC)—an active compound in cannabis—has been found to inhibit the formation of amyloid plaques in the brain based on scientific research from the Salk Institute for Biological Studies in California. These toxic clumps of protein are thought to begin the progression of Alzheimer’s disease.
While other studies have shown that cannabinoids might be neuroprotective against Alzheimer’s disease symptoms, this particular study demonstrates the effect cannabinoids have on both the accumulation of amyloid beta proteins in nerve cells and inflammation. The scientists tested the effects of THC on human neurons grown in the lab that resemble the effects of the disease.
When THC is consumed, the compound passes from the lungs into the bloodstream, where it attaches to cannabinoid receptor (CB) 1 and 2. These two types of receptors are found on cell surfaces throughout the body.
Upon binding to these receptors, the compound produces the majority of cannabis’ psychological effects, such as the “high,” and considered an effective treatment for various health conditions due to its natural pain-relieving properties. Research suggests that THC has another effect on aging brains, helping the body remove the “plaques”—or toxic accumulations—of amyloid beta.
While the main cause of Alzheimer’s disease is not known, it is thought to result from the build-up of two types of lesions: amyloid plaques and neurofibrillary tangles. Amyloid plaques are positioned between the neurons as thick clusters of beta-amyloid molecules and neurofibrillary tangles are caused by deficient tau proteins that accumulate into a dense, insoluble mass in the neurons.
It is unknown why these lesions start to appear in the brain, but studies have linked inflammation in the brain tissue to the increase of plaques and neurofibrillary tangles. With cannabis, scientists aim to find a way to ease brain inflammation while encouraging the body to eliminate these lesions at the same time.
In 2006, researchers at the Scripps Research Institute discovered that THC impedes the formation of amyloid plaque by blocking the enzyme in the brain which produces them. This new research shows that it can also get rid of a damaging inflammatory response from the nerve cells, ensuring they survive.