The research suggests that the creation of a drug with certain properties similar to those in marijuana might help prevent or delay Alzheimer's disease. The exact cause of Alzheimer's is still not known, but chronic inflammation in the brain is believed to contribute to memory impairment.

"Could people smoke marijuana to prevent Alzheimer's disease if the disease is in their family?" asked Gary Wenk, professor of psychology at Ohio State University and an investigator on the study. "We're not saying that, but it might actually work. What we are saying is it appears that a safe, legal substance that mimics those important properties of marijuana can work on receptors in the brain to prevent memory impairments in ageing. So that's really hopeful."