The use of marijuana for medical purposes remains a hot debate topic, in spite of the fact that it is already being recommended as a treatment for a number of conditions including epileptic seizures, inflammation, muscle control problems, pain and nausea.
Typically, medical marijuana may be smoked, vaporized, eaten (in the form of candies or cookies), or drank as a liquid extract.
There is already ongoing research looking into the use of marijuana to treat mental disorders. The latest study done by researchers at the University of Bonn and The Hebrew University of Jerusalem might add fuel to the fire, so to speak, as the team was able to show how THC, a cannabis ingredient found in marijuana, might be helpful in reducing or reversing brain aging.
THC (delta-9-tetrahydrocannabinol) is the molecule that gives marijuana its intoxicating effect, essentially, the ingredient that makes people ‘high’, by altering the body’s internal cannabinoid signaling system. Based on previous studies, as the body ages, its endogenous cannabinoid system slows down, producing fewer of its signalling molecules and expressing lesser of the receptors they bind to. When this happens, the body becomes more vulnerable to diseases that affect several day-to-day functions including appetite, motor control, sleep, mood, temperature regulation, immune system function, reproduction and memory. Accordingly, this decline in the cannabinoid system is likely linked to the deterioration in mental ability that comes with aging.
Focusing on the effects of THC on cognitive ability, the research team administered low doses of THC for four weeks on mice of three age groups: two-month olds (young mice); 12-month olds (middle-aged mice); and 18-month olds (elderly mice). All of the mice were subjected to learning and memory tests (including a water maze test and object recognition tests). The results showed that in all tests, mice that received THC did not display a cognitive decline associated with aging. In fact, they acted as if they were two months old, in other words, like they were young.
In terms of brain activity, similar results were found. Specifically, in mice treated with THC, the activity of genes normally associated with aging did not wane as they should have. Rather, they continued to be as active as if they were the brains of two-month old mice. Moreover, the number of connections between the brain’s nerve cells increased again, an important precursor for the ability to learn and form memories.
As explained by Prof. Andreas Zimmer, leader of the research team: “The treatment completely reversed the loss of performance in the old animals… It looked as though the THC treatment turned back the molecular clock.”
On the other hand, THC seemed to affect young mice negatively. Instead of showing improvement in doing tasks, their ability seemed to decline. According to Zimmer, this is an indication that under and over-stimulation are both harmful. In young mice (as well as in young people), the endogenous cannabinoid system is quite active, which means giving them additional THC might result in overstimulation, and consequently, a decline instead of an improvement in cognitive function. But in older mice, giving THC results in just the right amount of stimulation, and therefore, an improvement in cognitive ability.
These findings suggest that THC may indeed be instrumental in reversing the effects of aging in the brain-at least when it came to mice. The next logical step forward is to find out if the same findings will have the same effect on humans. The team seems hopeful and positive about the prospective effects of their research, especially on conditions like dementia.
The research was recently published in the journal Nature Medicine.