N-Acetyl Cysteine (NAC) is a stable form of the essential amino acid L-cysteine. Cysteine is a precursor for glutathione, an important antioxidant in the body. Cysteine also serves as a major sulfur source for many body components. It also may help with Alzheimer’s and also eye health.
However, recently some researchers at the University of Virginia Health System have found some potential side effects which may be troubling for some people who use this nutrient in high doses. But…they are not sure, because these potential side effects have only been found in rats and may not occur in humans…and they did not occur in all rats.
The potential side effect is that NAC can form a red blood cell-derived molecule called nitrosothiol. This could result in your body thinking that it has an oxygen shortage, which in turn can lead to pulmonary arterial hypertension (PAH).
Because it is likely that some of the media will jump on this ‘bandwagon’ I thought that I should mention a few important points about this first so any negative reports don’t raise any concerns for you.
1. The doses in their experiments were VERY high. In fact, I sometimes wonder why the researchers do these experiments and then publish the results because it really is quite meaningless in the real world, unless they are trying to discredit a particular nutrient. Almost every substance when taken in excess can cause a side effect.
2. Many body builders take very high doses of NAC. Up to 2000mgs of more a day in 3 – 4 x 500mgs capsules. I am unaware of any one having the side effect referred to by the researchers.
3. NAC is a valuable nutrient, and a safe one.
Even though there is no evidence of any side effects in humans, as I say frequently you should never ingest any single ingredient in high doses. They should always be combined with other nutrients and co-factors.
Unfortunately there is and always will be a group of consumers that feel more is better, and so when they hear some good results about a particular nutrient they want to take large doses of it and of course the manufacturers and marketers respond and give it to them.
Bottom line…NAC is SAFE. We use it in our formulas but in low amounts. For example, we only use 35mgs of it in our Total Balance and that is with the full dose of 6 tablets per day. It is an important nutrient and it plays a valuable role.
