Early last month, scientists at the University of Bonn have discovered in tests on mice, that regular, low doses of tetrahydrocannabinol (THC) – the main psychoactive ingredient in cannabis – impaired memory and learning in young animals, but boosted the performance of old ones. To investigate whether it works in humans, the scientists plan to launch a clinical trial later this year.
“If we can rejuvenate the brain so that everybody gets five to 10 more years without needing extra care then that is more than we could have imagined,” claimed researcher Andras Bilkei-Gorzo. Currently, Alzheimer's is the most expensive disease in America, costing more than cancer and heart disease. In 2017, the direct costs to American society of caring for those with Alzheimer's and other dementias will total an estimated $259 billion.
Writing in the journal Nature Medicine, the scientists describe how they gave a month-long course of daily THC to mice aged two months, one year, and 18 months. The mice were then tested to see how fast they solved a water maze, and how quickly they recognized familiar objects such as mice they had met before.
Without the drug, the younger mice aced the tests, while the older ones struggled. But infusions of THC had a dramatic impact on both groups. The performance of the younger mice plummeted on THC, while older mice improved so much that their scores matched those of healthy drug-free young mice. The benefits lasted for weeks after the infusions ended. None of the mice displayed the strange effects one might expect from doses of THC.
“These results reveal a profound, long-lasting improvement of cognitive performance resulting from a low dose of THC treatment in mature and old animals,” the scientists write. The boost in brain function was linked to an apparent restoration of gene expression in the brain to more youthful levels.
The German team believes that the drug works by stimulating what is known as the endocannabinoid system, a biochemical pathway that becomes less active with age in mice, humans and other animals. “I’m sure that what we are seeing are the long-term consequences of normalizing the system,” Bilkei-Gorzo said.
This type of science is imperative for an aging "baby-boomer" generation that is going to see the effects of aging and transition to medically-funded processes linked to aging to prolong their quality of life. Here's hoping the science pays off.