It makes most people a little foggy-headed, but scientists are investigating whether an active ingredient in cannabis could actually stave off dementia.

A team from Neuroscience Research Australia is in the early stages of research examining if one of the main active ingredients in cannabis, called cannabidiol, could reverse some of the symptoms of memory loss in animals.

Tim Karl, a senior research fellow with the group, said cannabidiol does not have the same psychoactive effects as the main component of marijuana, THC, but it has been found to have anti-inflammatory, antioxidant and other effects that could be beneficial for the brain.

“Back in the day cannabis was used for medical purposes, I'm talking 200 years, 100 years back, then at some point people discovered it had other effects and, as quite often happens in our society, people decided it was a bad drug,” he said.

“But it's not one compound, it is a mixture of 60 different compounds, and you just have to look at those different compounds because some of them might be good for you.”