There are perhaps hundreds of glutathione supplements out there. But narrowing them down to the best choice is not that hard if you have a clear idea of why you want to supplement glutathione. For a person interested in long term use of glutathione supplements to promote wellness, there are a few products that should be eliminated from consideration. These are:
Oral glutathione. There is no evidence that taking pure, reduced glutathione by mouth increases glutathione levels. The glutathione molecule is largely broken down in the digestive tract. The little that makes it to the bloodstream is not absorbed very well.
Other methods of direct delivery of glutathione. Glutathione levels need to be increased at the cellular level where it does most of its work. Various schemes for getting glutathione into the cells of the body have been tried: intravenous, nasal, sublingual, liposome-enclosed. First or all, there is not a lot in the way of studies in peer reviewed medical literature that verify whether any of these schemes work in humans. Secondly, the body has its own complex system for producing, recycling and regulating glutathione. Introducing glutathione externally is going to work at cross purposes to this system. Long term use will probably be disruptive and may create as many problems as it solves.
N-acetyl cysteine. N acetyl cysteine, often referred to as NAC, makes the amino acid cysteine more available to the cells of the body. Availability of cysteine is a limiting factor to production of glutathione. However, long term use of NAC is probably not the best choice. Part of the NAC gets converted to S-nitroso-N-acetylcysteine which has been shown to increase blood pressure in the lungs and right ventricle of the heart (pulmonary artery hypertension) in mice. Some evidence suggests that this may be relevant to long term use in humans. NAC has been observed to produce a number of other minor side effects.
How about products that contain NAC? There are several products of this kind. It does not appear as though any evaluation of these products has been reported in peer-reviewed medical literature including systematic studies of the side effects of these products. One in particular has undergone short term clinical evaluation for effectiveness. That's fine for short term use, but it fails to address the concerns described above.
So, what's left? A long term program should include a cysteine donor to support production of glutathione and support for other aspects of glutathione metabolism. The most reasonable choices are:
Whey protein concentrate. Undenatured whey protein is extracted from raw milk. The milk can't be pasteurized or it will damage the structure of the protein, but don't worry. The processing method insures that whey protein concentrate is sterile. Ironically, pasteurized milk is not perfectly sterile. The reason whey protein increases glutathione is apparently because the cysteine is in the form of cystine and gamma glutamyl cysteine. A number of studies in medical literature clearly show that whey protein does increase glutathione levels in humans. Animal studies clearly show that whey protein increases life span. A study on Syrian hamsters showed an average increase of up to 49% in males and 40% in females over a control group. A daily dose containing 20g - 25g of protein is probably about right for adults.
The composition of whey protein has a significant effect on effectiveness at supplementing glutathione. Composition and price of whey protein varies considerably. These products can be rather expensive. It appears that a sort of "sweet spot" of economy and effectiveness sits at around 10% bovine serum albumin and 10% immunoglobulin. These are the two fractions that seem to have the greatest impact on effectiveness. The protein composition of many whey products is not given. See below for some resources that you might find helpful.
alpha lipoic acid. This antioxidant has been shown to increase glutathione levels probably by supporting the process by which the body recycles glutathione. A daily dose of 250mg is probably safe. Lipoic acid is found in almost all foods, but slightly more so in kidney, heart, liver, spinach, broccoli, and yeast extract. The amounts are very tiny. Many inexpensive supplement products are available. Basically, they are the only way to get any significant amount of alpha lipoic acid.
Conjugated linoleic acid or CLA. The reason why glutathione levels decline with age are not well understood. It may be due to down regulation, that is, the mechanism that regulates glutathione levels is causing production to cut back. Reports in literature describe how CLA up regulates glutathione levels while decreasing a common effect of oxidative stress, lipid peroxidation. This requires more study, however. CLA occurs naturally, mostly in various kinds of meat. Grass-fed animals can produce 300-500% more CLA than those of cattle fed the usual diet of 50% hay and silage, and 50% grain. To supplement, take an 800mg gelcap every 1 to 2 days.
Charles_Ware
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