A study published today reports that the brain’s natural cannabinoid system becomes less active with age, potentially contributing to memory loss and other age-related changes, while research involving older animals suggests low doses of THC may help counter some of these effects.
The study, published October 16 in Nature Reviews Neuroscience, was authored by researchers at the University of Bonn’s Institute for Molecular Psychiatry in Germany. It examines how the endocannabinoid system changes throughout life and its potential role in maintaining healthy brain function as people age.
The endocannabinoid system is a network of naturally occurring compounds and receptors that helps regulate memory, learning, inflammation, metabolism and communication between brain cells. According to the review, this system generally exhibits relatively high activity during early adulthood before progressively declining with age.
Zimmer found that disruptions to endocannabinoid signaling are associated with several processes involved in brain aging, including increased neuroinflammation, reduced formation of new neurons, impaired communication between brain cells and declining cognitive performance. Changes in the system may also influence how genes are regulated and how the brain maintains its ability to adapt to new information.
The review highlights research demonstrating that low-dose THC treatment can improve several age-related brain changes in older animals. In one previously published study involving mice aged 12 and 18 months, sustained treatment with low doses of THC reversed age-related declines in learning and memory performance.
Those improvements were accompanied by changes in the hippocampus, a brain region essential for learning and memory. Researchers observed increased connections between neurons and changes in gene activity that made the brains of treated older mice more closely resemble those of younger animals.
Notably, the same THC treatments produced different effects depending on age. While older mice demonstrated improvements in cognitive performance, younger animals experienced impairments, suggesting that the effects of THC on brain function may depend partly on the condition and activity of the endocannabinoid system.
The review also identifies potential connections between cannabinoid signaling and other aspects of brain health, including the regulation of inflammatory responses, the maintenance of neural connections and the brain’s ability to adapt to cellular stress.
Zimmer concludes that restoring or supporting endocannabinoid activity could represent a promising approach to addressing certain aspects of brain aging. However, clinical research involving older humans remains limited, and additional studies are needed to determine whether the benefits observed in animals can be replicated in people.
