As we’ve previously discussed, the liver breaks down THC to become more bioavailable while the human body digests cannabis edibles. This part of the digestion process allows THC to pass through an important cell membrane that’s located in the brain. It’s called the blood-brain barrier; but what is the purpose and importance of this membrane?
The blood-brain barrier exists as an extra layer of protection for the brain. Only water, certain gases (such as oxygen), and substances that are soluble in fats and lipids can easily cross the blood-brain barrier. This provides a natural defense against harmful pathogens and toxins that can be present in blood. It also gives cannabinoids (such as THC) a direct route to the brain, since they’re soluble in fats and lipids.
Once cannabinoids reach the brain, they’re finally absorbed and are able to produce their unique effects. In short, this means that the blood-brain barrier can seriously speed up how quickly cannabis edibles are absorbed by the body.