An "unknown portion" of the population seems to be functionally immune to the effects of edibles, or at least seem to have very high tolerances for ingested THC. The Boston Globe describes this population as being "ediblocked." The weirdest part? Most consumers who report being "ediblocked" seemingly have no problem feeling the psychoactive effects of smoking cannabis.
While scientists and medical professionals are aware of this strange phenomenon, they have yet to find a way to definitively explain it. They also understand that the inability to fully understand this phenomenon can have "'serious implications for dosing in medical marijuana treatment' as well as as well as arousing questions on the validity of the blood tests which indicate cannabis-related impairment."
Although research on the subject is limited, some scientists like Dr. Staci Gruber, director of the Marijuana Investigations for Neuroscientific Discovery programs at the McLean Hospital, believe they may potentially have an answer.
"The hypothesis is that those who are ediblocked have an unusual variation of a “key liver enzyme which could essentially be too efficient at processing ingested THC, turning the compound into its ‘active’ high-inducing metabolite and then its inactive waste product before the active form can enter the bloodstream or brain.”
The CYP2C9 gene, which produces the enzymes involved in protein processing and transport, plays a crucial role in the metabolism and breaking down of drugs. The gene also "encodes the enzyme that shepherds THC through its three-step metabolic transformation.” Dr. Gruber and other researchers believe that individuals with this gene may be breaking it down so quickly in their bodies, that the THC "doesn't have an opportunity to create the psychoactive effect."
Being "ediblocked" creates an unfortunate barrier for those who want to consume cannabis products without smoking or inhalation. Additionally, consumers with this gene are missing out on the benefits and medicinal properties available from edible products.
There is not yet enough evidence to determine the validity of this hypothesis, but the researchers behind this theory definitely present some interesting points. As more research is conducted, hopefully our industry will gain a better understanding of how and why some people are "ediblocked."