Has anyone heard of it?
I came across their research page and found it quite interesting. Makes sense in paleo terms. I can't comment much on the science though.
The normal inflammatory response is, in part, a burst of free radicals produced
by the immune system in response to an injury. This natural production of free
radicals occurs to prevent infection and to promote healing at a site of injury.
In simple terms, a free radical is an electrically charged particle. This electrical
charge occurs because the free radical is missing an electron. To become
stabilized, a free radical must "steal" its missing electron from another
molecule. When the electron is stolen from an invader (e.g., bacteria), the
invader's molecular structure is damaged, which leads to its death (as intended
by the immune system). When there are no invaders left to destroy and when
there is a lack of electrons available from antioxidants to stabilize excess free
radicals, free radicals then turn to the only other source from which they can
steal electrons - healthy cells. The resulting damage to and death of healthy
cells, from loss of electrons to free radicals, further signals the immune system
for additional help.
Shielding, via grounding, allows the body to have all of its electrons available to carry on their normal functions in the body, which include the
stabilization of excess free radicals.
Quotes from "Grounding the Human Body to Earth Reduces Chronic Inflammation and Related Chronic Pain"
More of their research here.