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| Cysteine / N-acetyl-cysteine (NAC) |
Last updated: Nov 05, 2009 |
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Cysteine / N-acetyl-cysteine (NAC) |
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N-Acetyl Cysteine (NAC) is the pre-acetylized form of the simple amino acid cysteine. It is a powerful antioxidant, a premier antitoxin and immune support substance, and is found naturally in foods. It is a precursor for glutathione, along with glutamine and glycine, an important antioxidant that protects cells against oxidative stress. In addition to maintaining intracellular glutathione levels, NAC supplementation has been shown to suppresses HIV replication, to be protective against cell damage caused by chemotherapy and radiation therapy, to be immune enhancing, to protect against toxins as acetamenaphen and other drugs, mercury, lead, and others, and is mucolytic, that is, it breaks up mucus seen in bronchopulmonary disease as cystic fibrosis, chronic bronchitis, asthma, and pneumonia.
NAC has all the properties of L-Cysteine but is more water soluble and said to be more bioavailable than L-Cysteine. It is known and marketed as an "anti-amalgam" medicine, because it helps remove mercury from the body. It also generally improves the body's immune system, making it better able to fight off disease. It is freely available from health-food shops in many countries. NAC has neither a sedative or stimulant effect, and is a safe substance showing excellent tolerance in patients.
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 Cysteine / N-acetyl-cysteine (NAC) can help with the following: | | | | | | Aging |  Parkinson's Disease / Risk | Both cysteine and NAC increase glutathione levels. |
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Allergy |
Allergic Rhinitis / Hay Fever| | N-acetylcysteine is recommended at 200mg three times per day. |
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Environment / Toxicity |
Mercury Toxicity / Amalgam Illness| | The ability of NAC to enhance methylmercury excretion when given orally, its relatively low toxicity, and its wide availability in the clinical setting indicate that it may be an ideal therapeutic agent for use in methylmercury poisoning. [Environ Health Perspectives, 1998, 106(5): pp.267-71] Earlier concerns over NAC causing mercury to accumulate in the brain and kidneys, as can occur with L-cysteine, now appear to be unfounded. The initial concerns were opinions only, based on L-cysteine research, not NAC research. Still, some clinicians feel that symptom worsening occurs with the use of large doses of NAC (over 300mg per day), especially if they already have elevated levels of L-cysteine. If L-cysteine levels are elevated, cystiene containing products like protein powders should be avoided. |
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Musculo-Skeletal |
 Dupuytren's Contracture| | Here is some information from this site: http://www.dupuytren-online.info/research_projects_dupuytren.html
In laboratory experiments NAC can slow down growth of Dupuytren cells (Juergen Kopp et al. "N-Acetyl-L-Cysteine abrogates fibrogenic properties of fibroblasts isolated from Dupuytren's disease by blunting TGF-ß signalling" J. Cell. Mol. Med. 10 (2006) pp. 157-165, see also our page on NAC therapy. It is unclear to whether the laboratory concentration levels of NAC can be achieved in a real hand and to what extent lower concentrations would be beneficial. As far as we know there are no clinical results available about the effect of NAC on Dupuytren's contracture (Dupuytren's disease) or Ledderhose disease in real life. Therefore we, in cooperation with Dr. Charles Eaton of the Florida handcenter, collected reports from Dupuytren patients who are taking NAC or have taken NAC. Here are the results (data collection ended October 2007).
A total of 10 patients participated initially. Three patients stopped taking NAC (brand name e.g. ACC) after less than one month. Below are the reasons for stopping to take NAC:
- one patient because of continuing stomach problems after 1 week of NAC
- one patient because of permanent fatigue
- one patient for private reasons.
Patients' details:
7 patients have taken NAC for more than 1 month. Below percentages refer to a total of 7. Please note that a total of 7 doesn't provide very reliable statistics, the percentages are below thus not to be taken for granted. - All of those 7 patients were male.
Age: 42 - 60 (average = 51.5)
Stage of disease: all patients suffered from Dupuytrens, 43 % additionally from Ledderhose, 14 % also from Peyronie. Most patients had one or more surgeries already.
Dose: typically 600 mg NAC/day; 1 patient temporarily takes 1 g /day
Application period: 3 - 6 months.
Positive results:
- typically not much change in the first 2-3 months but situation stable
- after 3-5 months 86 % of the patients report that their nodules became somewhat softer
- one patient (14 %) reports that his Ledderhose nodules became softer after 3 months but that his Dupuytren cords kept growing slowly. Another patient reports of a growing cord after 5 months.
- one patient reports after 5 months that his Dupuytren nodule shrank to about 2/3 its initial size. Another patient reports after 3 months that his Dupuytren nodules became "somewhat smaller".
- one patient reports that his grip improved after 4 months.
Summary:
Taking NAC over 2+ months seems to soften nodules. Nodules seem to grow slower or might in favorable cases even shrink to some extent. Cords seem to continue growing but possibly slower. We have no reports what happens when taking NAC is discontinued.
A better controlled clinical research might make sense as next step. Dr. Eaton suggested that taking NAC orally might not be sufficient to achieve high concentration at the tumor itself. Other means of application might be more efficient and worth investigation.
Observed side effects:
One patient reported an initially aching stomach. See also above reasons for stopping to take NAC. |
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Organ Health |
COPD (Chronic Obstructive Pulmonary Disease)| | Oxidative stress is closely linked to inflammation. The inflammatory process in patients with stable COPD is dominated by macrophages, CD8+ T-lymphocytes and neutrophils, and to a lesser extent mast cells, in the bronchial submucosa and alveoli 5. Increased production of mediators, such as interleukin (IL)-8, tumour necrosis factor- (TNF-) and leukotriene B4, which both attract inflammatory cells and increase oxidant production by these cells, has been found.
Attenuation of oxidative stress would be expected to result in reduced pulmonary damage and a decrease in local infections, contributing to attenuation of the progression of COPD. At present the only antioxidant widely available for the treatment of patients with COPD is N-acetylcysteine (NAC).
An open clinical trial including 1,392 patients demonstrated the efficacy of NAC at a dose of 600mg·day in reducing the viscosity of expectorations, promoting expectoration and reducing the severity of cough. After 2 months of treatment with NAC, the viscosity of expectorations improved in 80% of cases, the nature of the expectorations improved in 59%, difficulty in expectorating improved in 74% and the severity of cough improved in 71%. [J Int Med Res 1983;11:279–284]
Improvement in clinical symptoms as a result of treatment with NAC has been shown in a long-term double-blind trial with parallel groups conducted in several centres to which 744 patients with chronic bronchitis were recruited. Patients were randomly divided into two groups, one treated with NAC and the other with placebo. The results confirmed the efficacy of NAC regarding the parameters related to bronchial hypersecretion. [Eur J Respir Dis 1980;61: Suppl. 111, 93–108] |
Blepharitis| | 40 individuals with chronic posterior blepharitis were randomly assigned to receive standard therapy, either alone or in combination with oral NAC at 100mg tid for 8 weeks. The standard therapy was topical steroids and antibiotics, warm compresses to the eyelids twice a day, and the use of artificial tears. The group receiving NAC had a statistically significant improvement over the control group. These findings suggest that NAC could provide relief for individuals with this persistent and difficult-to-treat condition. [Cornea 2002;21: pp.164-8] |
Kidney Failure| | Oral treatment with acetylcysteine (400mg twice daily) reduced serum creatinine concentrations in a controlled study of 121 patients with chronic renal insufficiency. [J Am Coll Cardiol 2002;40(8): pp.1383-8] |
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KEY | | May do some good | | | Likely to help |
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