Turns out two studies have shown that cannabinoids reduce brain inflammation. One study showed that it reduced damage by Tumor Necrosis Factor alpha (TNFa) and another study by inhibiting Nitric Oxide (NO) … that’s the good news.
   
The bad news is that your immune system requires NO and TNFa to kill off things like tumors and microorganisms … Killing things usually involves inflammation. But chronic inflammation itself can cause DNA damage that leads to cancers, dementia, etc. … its a catch 22. This may be why other studies have shown that marijuana may have a protective effect against certain brain tumors.
   
Another problem with artificially inhibiting NO in men is that erections require this molecule. This may be why there are reports of marijuana abuse leading to impotence.
   
So the bottom line is that these studies suggest that the appropriate use of cannabinoids (such as marijuana) may prove useful in certain neurological conditions. However, caution should be exercised in that its abuse could over-suppress inflammation and cause its own set of problems.
   
PS: We are not writing these to encourage recreational or illegal marijuana use. Where it is legal, it may be an appropriate part of a treatment strategy.
   
J Pharmacol Exp Ther. 1999 Mar;288(3):1357-66. (on nitric oxide).
   
Glia. 2003 Jan 15;41(2):161-8. (on TNFa)