L-Glutathione is a tripeptide formed by the three amino acids glutamic acid, cysteine, and glycine, which is one of the most powerful and widespread amino acids in nature. Functionally speaking, it belongs to the sulphurous group of amino acids along with cysteine, cystine and taurine.
(Reduced) Glutathione’s chemical name is N-(N-gamma-L-Glutamyl-L-cysteinyl)glycine. For simplicity’s sake, the abbreviation GSH is used.
There are virtually no living organisms - plants or animals - on this planet which do not contain gluthatione. Glutathione may very well have been one of the building blocks for the beginning of life; which took place in an environment rich in carbon monoxide, peroxide, methane, and ammonium, a chemical context that was much more poisonous and hostile than the one we live in at the present.
Already then, living cells needed antioxidant protection from the constant threat of being eaten by an environment rich in oxygen and poison. The distribution of gluthatione in nature and its functional presence in even the most primitive of organisms could indicate that this substance is one of the oldest antioxidants on earth.
Naturally, glutathione still works the same way it did during the evolution of life on this planet. Therefore, its range of activities is also uncommonly wide. And therefore, it is also a welcome factor in the modern environment which is becoming as toxic as the original environment, due to industrial pollution.
For the same reason, it has been suggested that glutathione could become a decisive factor in the detoxification of entire environments, e.g. dying lakes, where it could favour all of the organisms still alive, no matter how primitive they are, by blocking the toxic effects of pollution. It could offer life another chance of taking over in an otherwise doomed environment.
As it is the case with cysteine, it is the thiol group, SH, which is the active tool in the process of oxidation. Hence the name GSH which stands for active - also known as reduced -glutathione. When the reduced glutathione has done its job and has become oxidized, it is called GSSH (L-gamma-glutamyl-L-cysteinyl-glycine disulfide) because it absorbs yet another sulphur atom. This causes it to form a disulphide bond and become deactivated.
The process can clearly be compared with the transformation of cysteine to cystine with the same deactivating effect. The most important difference between the two processes, however, is that unlike cystine, glutathione can easily be reactivated for re-use. This recycling process demands e.g. vitamin C.
Glutathione has several protective functions in the organic environment. It is, as mentioned, a reducing factor – in other words an antioxidant. It has detoxifying properties in that it can neutralize dangerous chemicals.
It also has important functions within the immune response. It protects the structure of the red blood cells and their ability to function. Moreover, it works as a neurotransmitter in the central nervous system.
It is interesting that the GSH-concentration in the stomach in healthy people is very high. It is probably used by the body to protect the mucous membrane in the stomach wall from erosion caused by one of its own vital secretions, the gastric acid. GSH has been used experimentally and with good results in the treatment of stomach ulcers.
The oxidation from GS to GSSH mentioned above is not its only functional mechanism. GSH is part of an enzyme that depends on selenium - glutathione peroxidase - which, as the name reveals, is especially designed for neutralizing peroxides, which are overly oxidized compounds.
We are familiar with the substance hydrogen peroxide. It is the substance which gives the fake blonde her unnatural looking hair. When too much peroxide is used for too little hair, it can also make the fake blonde bald.
Hydrogen peroxide is an aggressive corrosive substance. If you spill some on the surface of a table, the table will never be the same. If you pour a very weak solution in an infected wound, it will etch away all infection, bacteria, and also the healthy cells that surround the area. However, new cells will appear when the wound heals so the later is a minor problem. However, it is worse when this corrosion occurs inside the body - e.g. in the sensitive cells in the central nervous system.
Numerous pollution substances in our environment either have or generate the same corrosive effect. When carbon tetrachloride, benzene compounds, plastic, colouring agents, herbicides, and spray pesticides occur, overly oxidized substances are formed.
The peroxides are harmful to cell walls and therefore vital bodily functions. Vulnerable polyunsaturated fatty acids, which are responsible for the transport and communication through the cell walls, are especially easily attacked by peroxides. This can cause cell death.
The job of the liver is to detoxify these overly oxidized substances - the peroxides - but the liver itself is in danger because it only has a certain capacity for neutralizing dangerous substances. When this capacity is exceeded, the liver is itself susceptible to attacks. If such an attack gets out of hand, the peroxide eats away at liver cells and thereby damages the liver.
All of this only underlines how important it is that GSH not only works "on its own" as an antioxidant, but also in its "extended" programmes along with the enzyme glutathione peroxidise, which specifically neutralizes the peroxides.
This enzyme is not the only one where GSH plays a key-role. The GSH transferases, which also operate within the liver, have an important role too. These enzymes aim directly at detoxifying toxic compounds by transforming them into relatively harmless substances which the body can easily discharge.
We do not know for certain how the GSH transferases work; but it seems like they use a technique which is much different from what we usually expect. Instead of chemically decomposing the toxic substance - a process which can be difficult and even impossible at times - the enzyme latches on to the actively toxic part of the polluting molecule, which disarms the dangerous substance. After this conversion, the body can freely and without risk handle the disarmed substance and get rid of it by means of its normal discharge system.
GSH, GSH-peroxidise, and GSH transferases have been vital parts of nature since the beginning of life. Now, we can safely say that they are of immediate importance again. These internal organic detergents can easily become a matter of life or death. The self-destructive mania of industries spreading out all of their toxic waste products is responsible for our growing need for internal resources in the shape of these life-saving substances.
The list of accumulated toxins which we have to cope with is already very long. Nitrates, nitrosamines, solvents, vinyl chloride and other waste products from the plastic industry, PVC, fungicides, antibiotics, birth-control pills, herbicides, clouring agents, insecticides, phenols, exhaust gasses, the hundreds of toxic substances in tobacco smoke, heavy metals such as mercury, cadmium, lead, arsenic, aluminium, and chromium, and the steadily growing supply of toxic medicines.
All of these have to pass through the liver and be effectively detoxified if we are not to be damaged by them. Unfortunately the above list includes far from all known toxic substances, and the amount of these substances is growing dialy.
It is better to prevent illness than to cure it. This is one of the oldest and most fundamental truths of the art of herbal medicine. However, it is something that very few people live by.
Naturally, it would be better if people in polluted areas were given preventive glutathione supplements, until the pollution could be eliminated. But this is not going to happen. Often, even though the risk of illness is well known, preventative treatment is neglected. Cancer is an example of an illness which might be prevented to some degree by GSH.
Several animal experiments have shown that chemically induced cancer can be relieved and warded off in by means of GSH treatment. Scientists have experimentally successfully treated liver cancer in rats with GSH.
Within a year of exposure to a potent liver carcinogen, all of the rats developed liver tumours. Four months later, some of the rats were given injections with 100 mg of glutathione a day. All of the rats which had not been given any treatment died but 81% of the rats which had received glutathione treatment survived. It is even more remarkable that in all of the treated rats there had either been a remission or the tumours had quite simply disappeared.
This amazing data have received very little attention! Seen from a purely scientific point of view, these results are so outstanding and promising that they should have brought about an avalanche of scientific research. However, the financial conditions that control medical research do not favour natural substances which cannot be patented and therefore cannot be monopolized. Consequently, the research has been focused on the patented substance NAC; a kind of cysteine that has also proved to have valuable anti-cancer properties.
However, many alternative therapists paid attention to results from the numerous promising experiments performed on animals and some have already begun using cysteine and glutathione in the treatment of cancer.
A large part of the literature on this subject does not deal with the direct beneficial influence of glutathione on cancer, but rather on its ability to relieve the often very severe side effects from the chemotherapy that cancer patients have to endure. This relieving effect is therefore very well documented.
As mentioned, glutathione can be found in all of the cells in the body, and in particularly large concentrations in the liver, the kidney, the pancreas, and the spleen. The highest concentration is found in the eye, especially the lens and the cornea.
Among all of the organs of the body, the eye is, biologically speaking, in a very unusual position. The eye is in fact an extension of the brain and the only part of the brain which opens up to the surface of the body. The eye is very sensitive, not least because of its exposed surface position, but also because all energy supplies, nutrients, renovation and other cellular services have to reach the eye through long and difficult channels starting deep inside the blood circulation of the body.
The exposed position of the eye, its unprotected surface, and its location make it particularly vulnerable to attacks from free radicals. These free radicals can lead to and age-related diseases such as macular degeneration, and glaucoma.
In some illnesses, it has been noted (not surprisingly) that the eye lacks a large part of its concentration of glutathione and other antioxidants - e.g. selenium and vitamin B2 (riboflavine). A similar reduction of nutrients has been observed in case of other eye illnesses, e.g. diabetic eye degeneration and blindness caused by multiple sclerosis. Animals which have been inflicted with cataracts via X-rays also have low glutathione concentrations in their eyes.
In light of this, many therapists have started giving patients with such eye problems therapeutic glutathione supplements and other relevant nutrients, and they have had very good results. The treatment has helped patients to maintain functional eyesight in spite of the imminent danger of going blind. Prevention is always easier than curing!
This therapeutic procedure is now so widely spread that many companies offer special dietary supplements containing eye nutrients.
The research on glutathione is in many ways still in its preliminary phase and the effects of glutathione on other illnesses are being considered.
It has been considered whether supplements have a good influence on Parkinson's disease and on patients recuperating after coronary thrombosis. GSH is expected to relieve low thyroid gland activity (hypothyroidism), stomach ulcers, and medicinal overdose.
If one wishes to take GSH, the question becomes how should GSH be taken?
GSH is a tripeptide, and proteins and peptides must be broken down into amino acids in order to be absorbed through the intestinal wall. According to this, peptides will either be digested or not absorbed at all if not broken down. It might therefore be considered to be a better idea to take GSH’s building blocks, cysteine, glutamine and glycine. This might be the case, but the synthesis of GSH does not take place unless a number of factors are present, including supply of co-operating nutrients above all.
Because those wishing to benefit form GSH are often often seriously ill, it cannot be assumed that these patients' bodies are capable of synthesising GSH from supplied amino acids.
Moreover, research has shown again and again that in practice it is only one of the three amino acids, cysteine which is the decisive factor in the internal production of glutathione. Under normal circumstances, there is not a need for therapeutic supplements of the two other amino acids -glycine and glutamine - to keep the internal production going.
However, it is still a dilemma that requires analysis. Recent literature on the subject shows that the total decomposition of proteins and peptides is not always necessary as a prerequisite for intestinal absorption. Some scientists noted direct absorption of glutathione in experimental animals; but when a measurement was performed on humans, poor absorption of glutathione and a subsequent unchanged concentration in the liver was found. However, cystein supplements, however, lead to increased GSH-values.
Some scientist have pointed out that this is not always the case. These scientists point to the fact that an oxidation provoked by iron and/or copper can ruin the cysteine. Perhaps this can be warded off by combining the cysteine supplement with selenium and vitamin C.
The real measure of glutathion’s effectiveness is of course clinical trails. One must first and foremost observe the patient who has been given glutathione supplements. If any positive results can be seen from this initiative, it can mean two things: either that the peptide is absorbed directly from the intestines without being broken down into amino acids, or that it is being broken down but then is re-synthesized again to some extension and has some effect. It is a fact that positive effects have been measured, and this is something which both the patient and the therapist will have to be content with for the time being.
However, GSH is an expensive preparation and the three amino acids are relatively cheap, and financial circumstances are often an important factor in an extensive treatment programme. In this case, we must accept without reservations that we cannot assess the economy in this kind of treatment because we do not know the cost/benefit ratios of these treatments.
Summing up, it can be said that GSH fights free radicals and the over-oxidation of fatty substances. It protects the cell membranes and their function and promotes blood vessel health. It removes heavy metals from the body and promotes the immune response. It protects against the carcinogen effect of e.g. aflatoxin and has made malignant growths shrink in rats. It also stimulates the heart.
Natural sources of glutathione
Glutathione levels in our food are highest in fresh fruit and vegetables, including asparagus, avocado, and especially in all forms of cabbage. It is also found in walnuts and fish.
Therapeutic dosage
In doses from 500 mg. and more, glutathione can sometimes ease inflammation of the gut. Cancer patients have been given 3 mg. a day.
See also: Amino acids in general and Amino acid complexes
