DANGER: Antioxidants and Multiple Chemical Sensitivity

A reader contacted me because her naturopath recommended NAC to help with MCS. She started having adverse reactions from it and contacted me.

On ideological grounds, the naturopath’s suggestions was reasonable. MCS tend to have high level of mercury and NAC is often used to remove it. Again IDEOLOGICAL.

Researching for published clinical experience of NAC being used for MCS, I found (to my surprise — I expected to find nothing) a beautiful study here from 2013 in

Oxidative Medicine and Cellular Longevity
Volume 2013 (2013)

: (IMHO, the naturopath should have known if she kept current on the literature)

“Our observations raise the possibility that treatment with vitamins, minerals, and antioxidants did not ameliorate the symptoms in most patients with MCS. In particular, we suggest that important clinical adverse events associated with oral supplements should be carefully evaluated when these nonspecific supportive therapies are prescribed to persons who have a clear history of mercury amalgam exposure, for example, ascorbic acid and thiol (sulfur derivatives) agents. Vitamin C (ascorbic acid) was not able to mobilize and remove mercury from tissues in both human and animal studies [56, 57]. Rather, some antioxidants worsen the retention kinetics of mercury in patients exposed to dental amalgam. 5 of 41 (12.2 percent) patients received secondary supportive therapy: 3 patients received selenium, 1 patient received alpha lipoic acid (ALA), and 1 received N-acetylcysteine (NAC). Adverse health effects occurred in 3 of 5 (60 percent). In two (2) of them, supplementation with selenium has been implicated in an elevation of the levels of serum antinuclear antibodies (ANAs) and one patient developed severe major aphthous stomatitis, whereas panic attacks were associated with the oral administration of alpha lipoic acid (ALA). 7 of 10 patients who have received intravenous (iv) administration of reduced glutathione (GSH) by continuous infusion, 5 of 7 (70 percent) patients had various adverse events while receiving GSH, including urticaria, asthma attacks, worsening of MCS symptoms, and cheilitis.”   — ouch!!!

  • ” The prevalence of metal immune hypersensitivity in a subset of 26 patients was 92.3 percent.”
  • “Our data show an increased prevalence of metal allergy and elevation of mercury levels in bioindicators among patients with MCS.”
  • “Professionals usually recommended supplements as a supportive therapy to reduce mercury burden. In theory, these supplements would bind and detoxify mercury that can be deposited in parenchymal pattern, reestablishing and maintaining the hepatic glutathione stores (i.e., N-acetylcysteine (NAC), selenium, and reduced glutathione, GSH). By contrast, there is no documented evidence either in animal model or in outcome studies that support therapy with supplements is able to remove mercury from human tissues [56 – 2008].”
  • “This may elucidate why monitoring blood concentrations of total mercury is of questionable clinical relevance as indicator of tissues body burden of mercury released from dental amalgam in humans. Consistently, preclinical studies have suggested direct evidence that low circulating mercury levels could reflect mercury disposition and redistribution to target organs, at least in adult sheep model [68]. Hence, concentrations of mercury in blood and urine may underestimate retention toxicity of mercury in the tissues and organs. In other words, there is the possibility that measurements of mercury in blood and urine do not fully reflect the actual mercury amalgam burden in humans [59].”


Table 6: New and classical systemic signs and symptoms associated with mercury exposure among MCS patients cohort.


  • (i) Angioedema
  • (iii) Cervical and axillary lymph nodes swollen
  • (iii) Dermographism
  • (iv) Enlargement of thyroid
  • (v) Eyelid myokymia (eyelid tremors)
  • (vi) Gastrointestinal malabsorption
  • (vii) Gingivitis – Stomatitis
  • (viii) Lichenoid contact stomatitis
  • (ix) Low-grade fever (fever of unknown origin—FUO)
  • (x) Muscle atrophy
  • (xi) Muscle fasciculations
  • (xii) Non-allergic rhinitis/vasomotor rhinitis-like
  • (xiii) Peripheral neuropathy
  • (xiv) Salmon-colored and/or pink’ rash
  • (xv) Sialorrhea (hypersalivation)
  • (xvi) Spasms
  • (xvii) Systemic contact dermatitis
  • (xviii) Tremors (upper limb, hands, fingers, face, eyelids, and lips)
  • (xix) Urticaria
  • (xx) White matter hyperintensity (by brain MRI)
  • (xxi) Xerostomia (dry mouth)


  • (i) Abdominal cramps
  • (ii) Anorexia
  • (iii) Atypical facial pain (persistent idiopathic facial pain)
  • (iv) Burning mouth syndrome (BMS)
  • (v) Burning pain (neuropathic)
  • (vi) Chemical odor intolerance
  • (vii) Chest pain (anterior or posterior, on the left side)
  • (viii) Confusion
  • (ix) Depression
  • (x) Dysesthesia
  • (xi) Fatigue
  • (xii) Flu-like symptoms
  • (xiii) Headache
  • (xiv) Insomnia
  • (xv) Intestinal movement disorders
  • (xvi) Intolerance to odors
  • (xvii) Itching (neuropathic)
  • (xviii) Muscle weakness
  • (xix) Nausea
  • (xx) Noise sensitivity
  • (xxi) Paresthesia
  • (xxii) Photophobia
  • (xxiii) Recurrent infections
  • (xxiv) Short-term memory disturbances
  • (xxv) Tachycardia
  • (xxvi) Thermal regulation disorders (low cold tolerance)
  • (xxvii) Trigeminal neuralgia
  • (xxviii) Vertigo

The use of herbs is also suspect..

“Concentration level of iron in blood and urine before and after treatment using the herbal medicine, widely used in Europe, is analyzed. Determination of Iron concentration in blood and urine was calculated … The analysis shows that the concentration of iron in blood and urine samples in both groups increased in some volunteers instead of decrease.” [2013]


Professional suggestions are without any published evidence supporting their typical recommendations and this study documented significant adverse risk. Professional are failing in “Do no harm” with MCS parients 😦

  • There appear to be some bacteria that can remove mercury [2016]
  • Grilling fish increases mercury intake [2013]

No published evidence, but…

  • I know one MCS person that can moderate a MCS attack by Olestra Chips. Some forms of mercury will dissolve in olestra [2010] .  There are no studies on the use of olestra to reduce mercury content.