SOME studies certainly show that smoking marijuana can have adverse effects on a developing brain, but it turns out smoking some dope could actually be beneficial for your mental capacity in old age.

That is the preliminary finding from an experiment conducted by German researchers on mice which found the active ingredient in cannabis, THC, might have helped reverse brain ageing and restored memory function in older mice.

“We repeated these experiments many times,” researcher Andreas Zimmer told New Scientist. “It’s a very robust and profound effect.”

Researchers at the University of Bonn, Germany conducted the study along with scientists from the Hebrew University of Jerusalem, and the results have since been published in the prestigious journal Nature Medicine.

“Here we show that a low dose of tetrahydrocannabinol (THC) reversed the age-related decline in cognitive performance of mice aged 12 and 18 months,” researchers wrote.

Like any other organ in the body, the brain deteriorates over time. As a result our cognitive abilities decline in old age leading to illnesses like dementia.

Researchers have long been looking for ways to prevent or reverse the trend and the latest study provides an interesting avenue for further exploration.

In the study, researchers gave older mice small doses of THC over a four week period. Afterwards, they tested the learning capacity and memory performance of the animals including such things as orientation skills and their ability recognise other mice.

The mice who had been fed the THC performed significantly better than the mice who were given the placebo and in line with the two-month-old control animals.

Speaking to The independent, lead researcher Andras Bilkei-Gorzo said the “THC restored the cognitive ability of the old mice to the level of the young ones.”

The team is now working to organise a small-scale study of around 100 volunteers aged 60 to 70 to find out if similar effects are observed in humans.

Meanwhile psychiatrist Dr Michael Bloomfield, from University College London, told the newspaper the “well conducted” study showed some potentially exciting results.

It “opens up a whole new chemical system, called the endocannabinoid system, as a potential target for new avenues of research which could include illnesses like dementia,” he said.

However he stressed that the research was in its very early stages and any benefit was likely highly contingent on the size of the dose.