It seems like nearly every day a new study comes out showing a previously unknown medical benefit for marijuana. But a new study has confirmed something that scientists believed was true for awhile: the ability for cannabis to prevent Alzheimer's symptoms.

A recent study found that tetrahydrocannabinol (THC), one of the active compounds in marijuana, has the ability to prevent the creation of a protein known as amyloid, which is believed to help contribute to the development of Alzheimer's. According to the study, THC passes through the bloodstream where it attaches itself to neuroreceptors in the brain. By attaching to those receptors, it prevents amyloid plaques from building up on the brain, which is believed to be one of the main causes for Alzheimer's. 

Scientists have long believed that marijuana could be used to treat Alzheimer's and other neurodegenerative diseases, but this is one of the first studies to explain why. 

“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,” says David Schubert from the Salk Institute for Biological Studies in California and one of the authors of the study.

Doctors are usually only allowed to prescribe marijuana for serious illnesses in the United States. But as more studies like these come to light, we'll need to consider the possibility of prescribing marijuana for preventive treatments.