This is a preliminary study - the first of it's kind, that I've seen. So, I'm treating this information with caution.
I'm posting this in case there some people out there that are supplementing with NAC and who may be experiencing this unexpected effect.
BTW, I take a multi-nutrient formula that contains about 600 mg of NAC. I currently don't currently plan on changing my routine.
The study examined the effect of N-acetylcysteine (NAC) and the results, published in this month's issue of the Journal of Clinical Investigation, indicate the antioxidant can form a red blood cell-derived molecule that makes blood vessels think they are not getting enough oxygen. This can lead to pulmonary arterial hypertension (PAH), a condition characterized by high blood pressure in the arteries carrying blood to the lungs.
While no one appears to be ringing any alarm bells, the researchers say the next step is to determine whether or not the effect on mice is reproduced in humans.
The researchers claim to have uncovered a new understanding of the way oxygen is sensed by the body and the chemical reactions that take place as a result.
"We were really surprised," said Dr. Ben Gaston, UV Children's Hospital paediatrician and study leader.
As part of the study, NAC and nitrosothiols were administered to mice for three weeks. The NAC was converted by red blood cells into the nitrosothiol called S-nitroso-N-acetylcysteine (SNOAC).
The 'normal' mice that received NAC and SNOAC developed PAH. Mice missing an enzyme known as endothelial nitric oxide synthase were protected from the adverse effects of NAC, but not SNOAC. These mice had not converted NAC to SNOAC, thereby suggesting NAC must be converted to SNOAC to cause PAH.
"NAC fools the body into thinking that it has an oxygen shortage," said Gaston.