One common myth about glutathione is that you can eat glutathione and consequently raise your body’s GSH levels. UNTRUE.
Eating glutathione supplements or foods rich in glutathione will not do the trick. Most of it will end up being broken down in your digestive tract and eliminated. Since glutathione is made within your cells, what needs to be accomplished is delivering the building blocks (“precursors”) of GSH to the cells themselves. The hardest glutathione precursor to find in our diet is the amino acid “cysteine” which must be in a form that survives the trip from your mouth to your living cells. This is not as easy as it sounds.
In nature, this usable form of cysteine can be found in eggs, but the eggs must be raw, otherwise the proteins that carry the cysteine are changed by heat and lose their efficiency as a “cysteine delivery vehicle”. Another good source would be meat, but again, the meat would need to be raw to be a competent source of cysteine. Aside from a well-prepared steak tartar, safe sources of raw meat are not abundant.
What about vegetables? You guessed it. Raw cruciferous veggies are a decent source, but you would have to eat a whole bunch of broccoli. Whey, a protein fraction of milk, is loaded with glutathione precursors. The problem here, as was the problem in eggs and meat, is that heat destroys the ability of these proteins to raise glutathione efficiently.
The other downside of whey, is that it may contain differing amounts of fat and lactose, which for many individuals is a no-no. In addition, the vast majority of whey protein on the market has been subject to multiple passes of pasteurisation, which is a form of heating. The glutathione building blocks in whey are very fragile, but techniques to extract these valuable proteins have been developed.
Researchers at McGill University had started investigating these GSH precursors as early as the 1980’s. The original research team headed by Dr. Gustavo Bounous eventually formed a private enterprise to further develop and market these glutathione building blocks. They adopted the trade name “Immunocal” for the eventual formulation and Immunotec continues to enhance this product.