Glutathione - PREDICTOR OF DISEASE, TOXICITY, VIRAL RISK AND LONGEVITY
BY DR LEIGH ROBINSON
GLUTATHIONE is a unique nutrient that is synthesized in the body from three amino acids (glutamic acid, cysteine, and glycine.) Glutathione's three major lifepromoting features include its ability to promote detoxification, resist proteolysis (accounting for its viral and cancerfighting properties), and serve as an antioxidant.
Glutathione exists either in the reduced, antioxidant form designated as GSH; or the oxidized, antioxidant-spent form, usually designated GS-SG. Since reduced GSH is the form that is given most of the credit for its health-promoting properties, it is recommended that when purchasing glutathione you look for "reduced" glutathione. If it doesn't say, "reduced", it probably isn't.
Glutathione has been found important in preventing and overcoming a variety of disease conditions in a number of ways, with its antioxidant function leading the way.
2) The mucosa of the lung and elsewhere increases in response to exposure to oxidants. Excess mucus is held in check by the presence of glutathione. Thus, a buildup of mucus can be one of the early signs of glutathione deficiency.
3) Chronic immune deficiency is another proven sign of a general reduction in glutathione status.
4) Since glutathione is an important conjugate of heavy metals and some pesticides, and since it is involved in the successful function of the detox enzyme CYTOCHROME P450, a history of exposure to any toxic substance combined with symptoms that are consistent with that exposure is sufficient evidence to assume a glutathione deficiency state.
A second sampling of the ability of glutathione to assist in detoxification can be seen in a study of rabbits. Like people, the rabbit liver becomes very hypoxic (low in oxygen) as toxicity deepens and glutathione status falls. A sharp rise in LDH (a marker of hypoxia) and a worsening of the liver's condition can be seen after only two days of hypoxic conditions. To see if glutathione alone is responsible for recovery researchers administered glycine intravenously to the test animals. (Glycine is known to decrease membrane injury due to hypoxia.) As expected, intravenous glycine did correct the hypoxia, similar to glutathione; but failed to restore the liver enzymes to normal, as did glutathione.
VIRAL PROTECTION: Viral infections of all types tend to be worse when the status of glutathione and other antioxidants is low. Many of these viruses enter the body as virions encased in a protective protein capsule. When the body environment is right, the capsule is lysed, releasing the virions. Dietary glutathione, by stimulating glutathione peroxidase, keeps the virions safely encapsuled by suppressing the lytic action. Thus, good glutathione status is key to viral protection.
CANCER PROTECTION: Several studies now suggest that low glutathione status is related to cancer onset and progression, and that good glutathione status is related to victory over cancer. One possible explanation is that glutathione is involved with activation of the T cells that seek out and kill cancer. Another can be credited to glutathione's ability to help keep a cancer attached to the epithelium long enough for the T cells to seek, find and destroy it. This becomes especially true in oral and pharyngeal cancer, where improved glutathione status helps fight these cancers through conserving a special glue-like protein of normal epithelium (E-Cadherin). E-Cadherin is the glue that holds cancer to the epithelium long enough for natural defenses to organize. When glutathione is deficient, the cancers own protease enzymes lyse the glue that keeps the cancer in place. In another scenario toxins can activate lysing enzymes. Once "free", the cancer is allowed to break through connective tissue in search of a blood supply, thereby setting the stage for metastasis. The person who has adequate glutathione status is able to hold the cancer in place long enough for the normal process of programmed cell death to occur, thereby killing the invader. The whole process is so important that the epithelium maintains an efficient system for acquiring glutathione directly from the bloodstream. The practitioner can facilitate the process by making certain glutathione is available when needed.
WHY GLUTATHIONE STATUS IS SO OFTEN COMPROMISED
Since the beginning of the industrial revolution, industry has annually added more than 3,000 tons of heavy metals to our environment. Each is extremely pervasive, eventually reaching humans mostly through air, water, and food. A good example is mercury, which has so polluted our environment that virtually every human now has some level of contamination. In addition, science has added nearly 300,000 chemicals to our environment that never before existed. Glutathione is needed to detoxify, but the total of these exposures place a greater demand on our glutathione status than our bodies can normally supply. An example of how just one of these toxins can alter glutathione status can be seen by examining the function of a common food additive, propylene glycol.
PROPYLENE GLYCOL is a temperaturesensitive preservative and antifreeze that keeps oils soluble at low temperatures. It's necessary for many foods that must be shipped during the winter. It is also used in a variety of foods to inhibit molds and unwanted fermentation. The problem is that the additive is known to oxidize when heated and deplete glutathione when eaten. Add this insult to a hundred others in our modern society and you can see how diet has a difficult time supplying all that is needed.
Because of the greater demands for glutathione placed upon us by viruses and environmental stresses, it is very important that a patient's diet include glutathione-rich foods and/or supplementation.
GLUTATHIONE FOOD SOURCES
Glutathione is present in many foods. To get an idea of the best sources and the full distribution of glutathione in the average diet, an analysis was made of the National Cancer Institute's Health Habits and History Questionnaire (HHHQ).
WHEN DIET IS NOT ENOUGH
The foods that are richest in glutathione are not uncommon. Yet, the level of intake required for health (between 100-150 mg/day) is seldom met. In one study that looked at this, the intake ranged from 2 to 131 mg/day, while in a second, the intake ranged from 3 to 200 mg/day. This means that a large number of people are falling short of what's required just to maintain good health, let alone what's required for unusual toxic exposures and disease conditions. It is for this reason that supplementation should be given serious consideration.
IS SUPPLEMENTAL GLUTATHIONE ABSORBED?
While it is well known that dietary glutathione can play a protective role in the intestinal tract, scientists have long held the opinion that glutathione from diet is mostly degraded by protease enzymes. This assumption is correct only when the intake is marginal (50 mg/day). At this low level, proteases generally destroy the particle. However, as the intake of glutathione rises above 50 mg/day, the particle resists protease action, thereby promoting partial absorption. At 100-200 mg per day, absorption of the intact particle is greater than 60%.
While intestinal absorption of intact glutathione is most certainly accomplished, the rate of absorption does not proceed in direct proportion to dosage. When glutathione is given orally, plasma GSH increases 2-3 fold. Yet, the rise does not last beyond 24 hours, and as the supplemental dosage is pushed above this level the rise diminishes.
In a study reported by D.P. Jones and colleagues of Emory University in Atlanta, Georgia during the 2000 Experimental Biology conference, the supplement was uniquely administered as a powder. Their findings revealed that glutathione absorbed more readily when it came in direct contact with oral mucosa, which suggested to them that perhaps a superior method of administration was to empty glutathione capsules directly into water, stir, and then drink. The improved result was related to the rise seen in the mucosa enzyme, GLUTATHIONE PEROXIDASE, observed during supplementation.
Based on all of the data presented here, I recommend that practitioners advise their patients to increase foods that are rich in glutathione and then supplement according to the following schedule:
I also recommend that practitioners consider advising patients to break the capsules open to enhance the permeability of the glutathione. Keeping the contents of reduced glutathione in a capsule until ready for use is a likely advantage since it would be less inclined to premature oxidation. For similar reasons the mixture should be consumed within 30 minutes to ensure that the product (once mixed in water) is delivered as the manufacturer intended in the health-promoting reduced state.