It turns out the fountain of youth might spurt smoke instead of a magical liquid. Well, that's not entirely true, but researchers did just discover that one of the active ingredients in marijuana – THC – was able to improve the brains of elderly mice to the level that they seemed like the brains of rodents who were only two months old.

Because mice only have a lifespan of 12-18 months on average, when the rodents get to be about a year old, they are considered seniors. In a study run by researchers at The Hebrew University of Jerusalem in Israel and the University of Bonn (UB) in Germany, mice aged two, 12 and 18 months were given a small quantity of THC over the course of four weeks. Even though THC is the compound in cannabis that causes its famous "high," the amount given to the rodents was too small to induce that effect.

The researchers then tested the cognitive performance of the mice through tasks such as how well they were able to orient themselves and how well they were able to recognize other mice. They also tested the mouse brains through chemical analysis.

In all cases, the mice who were 12 and 18 months old showed a rollback in ability and biology that was similar to what was exhibited by the two-month-old mice. Not only did they pass the cognitive tests as well as the younger mice, but the researchers discovered that the number of links between the brain's nerve cells had increased, and gene transcription patterns – the process by which RNA copies DNA – resembled those of the two-month-olds.

"It looked as though the THC treatment turned back the molecular clock," said Andreas Zimmer from the Institute of Molecular Psychiatry at UB.

Zimmer says that the study showed the anti-aging effects of THC because it functioned like the natural cannabinoids produced by our own bodies as part of our endocannabinoid systems, which decline as we age. As those substances naturally decrease, our brains age, so it makes sense that replacing them could have an anti-aging effect.

Next for the research team is finding out whether or not THC has the same effect in humans. If so, treatment with the compound could help combat diseases that impair our cognition as we age, such as dementia. If so, the brain-boosting effects of cannabis could join the other promising beneficial effects of the plant including pain and obesity reduction, nausea reduction in the face of chemotherapy, and the potential to combat Alzheimer's disease.

The results of the research have been published in the journal Nature Medicine.

Source: University of Bonn