Marijuana: The Alzheimer’s Fighter. Recent lab research has found that medical marijuana may be key to fighting marijuana. The cannabinoids in marijuana can help to prevent the buildup of certain proteins and plaques that cause the neurodegeneration we see in Alzheimer’s patients. Even more exciting is the suggestion that cannabinoids may actually help to clear these plaques, and may possibly increase brain function in Alzheimer’s patients! Here is what you need to know about this amazing and exciting discovery.