A new study suggests the drug may not only stop, but reverse memory loss due to aging

Recreational marijuana is now legal in eight states and medical marijuana in another 20 in USA. The popularity of the drug is rising, along with an increase in debates arguing the safety of the drug. A recent study in Germany believes it may have found something that would place a very large check in the “marijuana is good!” column—that marijuana can not only stop, but reverse memory loss associated with ageing.

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The study, published in Nature Medicine and conducted by researchers from the University of Bonn, concluded that when low doses of tetrahydrocannabinol (THC) were administered to ageing mice, they showed an improvement in cognitive abilities like memory and the ability to learn new tasks.

The study looked at three different ages of mice—2 months, 12 months and 18 months, which were representative of young, mature, and ageing brains. The mice underwent a number of different experiments, first with no drug administered, then again when treated with THC. One experiment tested the mice’s ability to remember how to navigate themselves out of a water maze. In the control test, the younger mice performed better than the mature and ageing groups. Under the administration of THC, however, the two older groups improved at the task and the younger mice did much worse. This, by the way, agrees with the assertion that THC has detrimental effects developing brains.

Another task had mice locate a specific object. With THC, the older mice performed just as well as young mice not treated with THC.

Zameel Cader, an associate professor in clinical neurosciences at Oxford University and who is also involved in the university’s $13 million cannabis research project, told Newsweek in response to the study that the findings indicate “a possible role for that compound in memory and cognition, which is relevant to disorders such as Alzheimer’s and other dementias.”

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While it’s important to note that the findings reflect testing only done on mouse models, the results indicate that a brain’s response to THC is at least somewhat attributed to age-related factors. So, what’s the outlook for potential human use? Cader told Newsweek that he thinks human testing is going to be a difficult barrier to overcome. “This is a challenge faced by anyone wanting to develop a therapy for a human disorder such as dementia. Human lifespan is very extensive. So the question would be, when would be the most appropriate time to give these kinds of medications? Over what period of time do you need to evaluate the effects? In humans, it could be years before an effect is noticed.”

Related: Is marijuana medicine?

So unfortunately, it will take a lot of time for us to confirm whether or not this can actually help aging humans suffering from memory loss. In the meantime, however, humans are doing some testing of their own, thanks to the rising popularity of recreational marijuana. But as we have said before, there are both positives and negatives associated to marijuana use, and while there are still a lot of unknowns, we recommend doing your best to educate yourself on what research is currently available.

Originally published on menshealth.com