See "Reactive Oxygen Species + Acetaldehyde" //www.curezone.org/forums/fm.asp?i=1959622
where acetaldehyde is an expected intermediate byproduct in the detoxification of alcohol to acetic acid. Are there other pathways resulting from yeast-released acetaldehyde that may lead to ROS accumulation in other cells in the body?
ROS within a cell are a natural consequence of oxygen-based aerobic respiration in the mitochondrial power plants [1] that keep the cell supplied with its biochemical energy source ATP (adenonsine triphosphate). Cells are miniature factories carrying out dynamic chemical reactions on a continuous basis. Reduction-oxidation (redox) reactions involve the change in "oxidation" state of the reactants, either via a gain of electrons (reduction) or a loss of electrons (oxidation). Since electrons are neither being created nor destroyed in the cellular processes there must be an equal number of electrons gained and electrons lost. Cells maintain pools of several redox couples such as cystine/cysteine, NAD+/NADH, NADP+/NADPH, and the oxidized and reduced forms of glutathione and metalloenzymes that can serve as electron acceptors or donors to ensure that electron transfer can occur in an efficient and balanced manner. When theses pools are inadequate or imbalanced, then the cell enters a state of "oxidative stress" since it can no longer perform its necessary chemical reactions that comprise its unique functions in the body.
Cystine is the oxidized form of two amino acid cysteine molecules joined by a disulfide bond:
The cystine/cysteine redox couple is the predominant low-molecular-weight thiol/disulfide pool found in plasma. It is possible to measure the redox potential (in millivolts) of the plasma thiol/disulfide redox pool. In healthy adults this is centered at approximately -80mv while in disease states it may become oxidized (less cysteine) to between -62 to -20 mv [2]. Inadequate dietary intake and absorption of sulfur-bearing amino acids can shift the redox potential towards the oxidized state associated with disease [3]. Oxidized extracellular Cys/CySS also can stimulate the generation of intracellular reactive oxygen species (ROS) [4].
Acetaldehyde in the gut can react with dietary cysteine to form a thiazolidine,
See "Cysteine + Acetaldehyde" //www.curezone.org/forums/fm.asp?i=1973900
Cystine with its disulfide bond,
See "Disulfide Bonds + Acetaldehyde" //www.curezone.org/forums/fm.asp?i=1958887
may be subject to side reactions with acetaldehyde that alter its structure as well, releasing a cysteine that can be attacked by acetaldehyde and a hybrid structure such as N,S-diacetyl-L-cysteine:
With this kind of disruption in progress, acetaldehyde can influence the status of the thiol/disulfide redox plasma pool and indirectly exert a deleterious impact on every cell in the body that depends upon this vital resource, even without actually coming into contact with the cells in question!
Diseases that have a genetic component but late onset may eventually manifest because of a gradual shift of the Cys/CySS redox potential until the vulnerable cells are no longer able to cope with the cumulative increasing oxidative stress. Parkinson's disease [5], amyotrophic lateral sclerosis (ALS) [6], and Leber hereditary optic neuropathy [7] all have connections to reduced capacity for dealing with oxidative stress.
The as-yet unrecognized factor that triggers these diseases may the ongoing exposure to acetaldehyde from increasing "commensal" yeast colonization in the body, something that can shift the redox potential to a critical point where the cells in the body are no longer able to deal with the ROS associated with normal function. This oxidative-stress-to-disease point may be different in each individual. Monitoring the redox potentials of the various redox couple pools, plasma Cys/CySS in particular, over time could provide an indication of both possible movement towards disease and the efficacy of therapeutic strategies (such as acetaldehyde scavengers and yeast reduction protocols) aimed at dealing with acetaldehyde toxcity.
[1] Turren JF, "Mitochondrial formation of reactive oxygen species.", J Physiol 2003 Oct 15;552(Pt 2):335-44.
http://www.ncbi.nlm.nih.gov/pubmed/14561818
[2] Ramierez A et al., "Extracellular cysteine/cystine redox potential controls lung fibroblast proliferation and matrix expression through upregulation of transforming growth factor-β", AJP - Lung Physiol October 2007 vol. 293 no. 4 L972-L981.
http://ajplung.physiology.org/content/293/4/L972.full
[3] Nkabyo YS et al.,"Thiol/disulfide redox status is oxidized in plasma and small intestinal and colonic mucosa of rats with inadequate sulfur amino acid intake.", J Nutr. 2006 May;136(5):1242-8.
http://www.ncbi.nlm.nih.gov/pubmed/16614411
[4] Zhu JW et al., "Extracellular cysteine (Cys)/cystine (CySS) redox regulates metabotropic glutamate receptor 5 activity.", Biochimie. 2012 Mar;94(3):617-27. Epub 2011 Sep 22.
http://www.ncbi.nlm.nih.gov/pubmed/21964032
[5] Grasbon-Frodl EM et al.,"Analysis of mitochondrial targeting sequence and coding region polymorphisms of the manganese superoxide dismutase gene in German Parkinson disease patients.", Biochem Biophys Res Commun. 1999 Feb 24;255(3):749-52.
http://www.ncbi.nlm.nih.gov/pubmed/10049782
[6] Valentine JS et al., "Misfolded CuZnSOD and amyotrophic lateral sclerosis.", Proc Natl Acad Sci U S A. 2003 Apr 1;100(7):3617-22. Epub 2003 Mar 24.
http://www.ncbi.nlm.nih.gov/pubmed/12655070
[7] Qi X et al., "Optic neuropathy induced by reductions in mitochondrial superoxide dismutase.", Invest Ophthalmol Vis Sci. 2003 Mar;44(3):1088-96.
http://www.ncbi.nlm.nih.gov/pubmed/12601034