US: Cannabis may contain compounds that slow the memory loss caused by Alzheimer's disease, new research suggests.
The effect, discovered in rats, may be due to the drug's strong anti-inflammatory properties, scientists believe.
Previous studies have indicated a strong link between chronic inflammation and progression of Alzheimer's.
Treating older rats with a synthetic compound similar to cannabis substantially improved their memories, researchers found. "These animals were able to hold on to key details of a specific task," said Prof Gary Wenk from Ohio State University. People who regularly smoked marijuana in the 1960s and 1970s rarely developed Alzheimer's, he added.
Rats had to navigate a water maze in which an escape platform was hidden. "The compound significantly improved the older rats' memories. They found the platform faster, suggesting that they were less apt to forget key information for this task. It's a pretty good prediction of how a human would respond to this drug."