Impaired Sulfur Oxidation
Some people have an impaired ability to oxidize and detoxify sulfur compounds. This is well known by the inability to safely process "sulfa-drugs". A buildup in the body of excess sulfur compounds can be uncomfortable and even life threatening.
Two forms of this impairment have been observed. One results in an inability to regulate the amino acid cysteine, and is indicated by an increase of cysteine levels in blood plasma, and other tissues samples along with discomfort in eating foods rich in sulfur amino acids.
The second impairment produces an inefficiency in converting sulfur dioxide and sulfides into non-toxic sulfate.
Anecdotes have been reported to us that impaired sulfur oxidation may occur commonly in people with Chronic Fatigue Syndrome, and "amalgam illness". ("Amalgam illness" is a term for chronic health problems stemming from lifetime exposure to mercury and other metals found in dental restorations.)
Paradoxically, and quite frustratingly, persons chronically ill can also have impaired glutathione synthesis and depletion of body stores of glutathione. Lack of adequate glutathione is implicated in poor immune function, poor synthesis and uptake of thyroid hormones, an increased rate of aging, and even poor hair growth.
When a person is a poor sulfur oxidizer they often find ordinary foods bearing sulfur compounds to be a source of discomfort. Broccoli and garlic being but two examples of foods which can contribute to uncomfortable excess cystiene levels in such people.
Excess free cysteine is a toxic condition and has been implicated in several degenerative diseases including Rheumatoid Arthritis, Alzheimer's Disease, Parkinson's Disease, Peripheral Neuron Degeneration, and others. (See our Science Page for journal references on impaired sulfur oxidation, glutathione, and other nutrition related topics.)
Poor sulfur oxidation would seem to be an inherited trait that might be made worse by environmental factors such as exposure to mercury and other heavy metals.
We have investigated the enzyme involved in sulfur oxidation of L-cysteine. Based on recent science literature, it appears the liver enzyme "cysteine dioxygenase" (CDO) is the primary regulating enzyme of cysteine. When this enzyme is not functioning at full strength, normal amounts of L-cysteine derived from food can elevate to dangerous levels in liver, plasma, and even the brain.
In healthy conditions the liver converts dietary L-cysteine into glutathione, taurine, sulfate, cystine, and allows a tolerated amount of unconverted L-cysteine to circulate in blood for direct uptake by body cells and organs.
Excessive levels of L-cysteine are controlled by the liver using the enzyme CDO to decompose the amino acid to non-toxic and rapidly excretable sulfate.
The enzyme "cysteine dioxygenase" (CDO) is an iron-histidine enzyme.
Another enzyme called "sulfite oxidase" has been implicated in dysfunction of the last step creating non-toxic sulfate from sulfur dioxide, and from toxic sulfide compounds. An inherited disorder called "molybdenum-cofactor deficiency" makes this condition severe, causing loss of eye lenses and usually an early death.
Less severe impairments of "sulfite oxidase" appear related to dietary deficiency or environmental depletion of the essential trace mineral molybdenum.
In response to the special dietary needs of those with impaired sulfur oxidation, and other trace metal enzymes we have created a nutrition program that includes essential trace minerals, and the essential amino acid histidine.
For a person with impaired sulfur oxidation attempting to rebuild healthy nutritional status we suggest looking at our Replenish and Glutathione Precursors - cysteine complement. When the ability to tolerate foods like garlic and broccoli is restored, then our Defense and regular Glutathione Precursors products should be considered.
Poor sulphoxidizers, persons with chronic seasonal allergies, elevated serum iron, or impairment of other mineral-enzymes should consider always adding the essential amino acid L-Histidine to their regular routine of nutritional supplementation.