Marijuana Ingredient Prevents Brain Damage In Mice: Study

Pot may not necessarily rot your brain.

According to a new study by pharmacologist Josef Sarne of Tel Aviv University, small amounts of tetrahydrocannabinol, or THC -- the active ingredient in marijuana -- may protect the brain before and after a head injury, the Jewish Press reports. Sarne’s study used mice to show that small doses of THC, around 1,000 to 10,000 times less than an average joint, over a period of up to seven days after an injury can jumpstart a biochemical process that protects brain cells from cognitive damage.

Researchers injected mice with low doses of THC before exposing them to brain trauma. About a month or two later, the mice performed better in tests that measured learning and memory than their rodent counterparts who did not receive THC, the Los Angeles Times reports.

Sarne says the results from his study show that marijuana has short- and long-term uses to treat brain injuries. For instance, he suggests heart patients could benefit from small amounts of THC given before surgery since cardiopulmonary heart-lung machines, used in open heart surgery, can interrupt blood supply to the brain. Patients with constant risk of brain injury, such as those with epilepsy, may benefit from regular low doses of marijuana.

Sarne isn’t the first to draw a link between marijuana and brain damage.

Previous studies have shown that small doses of THC given within 30 minutes of a brain injury can prevent brain damage. Sarne said his study, which uses a wider time frame, could be used for different kinds of brain injuries and would be safer over time, the Jewish Press reports.

But some studies show that heavy cannabis users are at risk of significant brain damage. In August 2012, Australian researchers showed that marijuana users who started in adolescence had higher instances of disruptions to white matter fibers in their brains.

Sarne’s study doesn’t dispute the fact that marijuana damages brain cells. In fact, one theory behind the study posits that the drug causes small amounts of damage that helps build resistance and trigger protective measures when the brain is presented with injury.