This essentially removes dietary cysteine from any participation in its normal downstream biological pathways creating a potential deficiency state if methionine intake or absorption is also impaired. This can impact the generation of taurine, glutathione, and sulphate ions. Usage of additional cysteine to compensate for this interference, associated with high alcohol intake, has been explored [2]. The non-prescription supplement Acetium™ [3] produced by the Finnish company Sartorius Biohit utilizes this reaction as an acetaldehyde scavenger in the stomach.
In the presence of dietary nitrates and nitrites , such as are used in the food processing industry for meat preservation, curing, and coloration; MTCA may be nitrosated to produce N-nitroso-2-methylthiazolidine 4-carboxylic acid (NMTCA) detectable in human urine [4]:
Nitrosamines are putative carcinogens [5] but vitamin C has been shown to have a protective effect [6].
Usage of cysteine as an acetaldehyde scavenger in a capsule for the yeast-released toxin has the potential drawback of missing the critical esophageal region adjacent to the thyroid,
See "Thyroid + Acetaldehyde" //www.curezone.org/forums/fm.asp?i=1955669
and needs to be cofactored with sufficient ascorbate to reduce the potential side reaction to NMTCA.
[1] Yamshita K et al., "Acetaldehyde Removal from Indoor Air through Chemical Absorption Using L-Cysteine",
Int J Environ Res Public Health. 2010 September; 7(9): 3489–3498.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2954559
[2] Salaspuro V et al., "Removal of acetaldehyde from saliva by a slow-release buccal tablet of L-cysteine", Int J Cancer 2002 Jan 20;97(3):361-4.
http://www.ncbi.nlm.nih.gov/pubmed/11774289
[3] "Acetium capsule reduces the amount of carcinogenic acetaldehyde in stomach"
http://www.acetium.com
[4] Ohshima H et al., "Occurrence in human urine of new sulphur-containing N-nitrosamino acids N-nitrosothiazolidine 4-carboxylic acid and its 2-methyl derivative, and their formation.", J Cancer Res Clin Oncol. 1984;108(1):121-8.
http://www.ncbi.nlm.nih.gov/pubmed/6746703
[5] Lin JK, "Nitrosamines as potential environmental carcinogens in man.", Clin Biochem. 1990 Feb;23(1):67-71.
http://www.ncbi.nlm.nih.gov/pubmed/2184959
[6] Lu SH et al., "Urinary excretion of N-nitrosamino acids and nitrate by inhabitants of high- and low-risk areas for esophageal cancer in Northern China: endogenous formation of nitrosoproline and its inhibition by vitamin C.", Cancer Res. 1986 Mar;46(3):1485-91.
http://www.ncbi.nlm.nih.gov/pubmed/3943105