Biological Functions

• Neurotransmitter
• Stimulates the inflammatory response of skin and mucous membranes.
• Stimulates the digestive enzyme gastrin.
• Required to regulate, utilize and excrete excess essential trace minerals such as copper, zinc, iron, manganese and molybdenum. (Binds with them.) (My blood levels of several minerals have tested high; does this indicate poor absorption into other tissues?)
• Forms metal-bearing enzymes and compounds
  • such as (among others)
    • Super oxide dismutase, SOD (This tested low on my Liver Detox Profile.)
    • Cysteine dioxygenase (CDO), the primary regulating enzyme of cysteine." (Also requires iron.)
    • toxic metal storage protein metallothionein — stores heavy metals in such a way as to prevent uncontrolled oxidation reaction. (Also requires L-cysteine)
  • Langford (6/05) comments "In fact, histidine is such a powerful chelator of heavy metals and minerals that it should probably be used only under medical supervision lest a deficiency of necessary minerals be created."
• Is regulated in delta-level sleep.

Tests & Indications

• Low blood plasma concentrations of the amino acid.
• Dysfunction of L-histidine dependent compounds
  eg, low/inactive CDO is indicated by
  • intolerance of sulfur-bearing foods like garlic and broccoli. See my page Sulfur-Rich Foods.
  • plus high blood plasma L-cysteine
• "Elevated 3-methyl histidine in urine is indicative of mercury or copper intoxication." from the AMALGAM email list
  (see directions for access)
  • message from Andy Cutler dated Sat, 3 Oct 1998,
  • Subject: SCIENCE:Indications for diagnostic tests relevant to amalgam illness + questions
• "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." (Impaired Sulfur Oxidation, on CFS Nutrition's site.)

Supplementation

Between meals without food or other accompanying minerals

Other Connections...

• On my page on Alpha Keto-glutarate (AK) I wondered what it means about my liver that most B vitamins give me "liver attacks." A reader wrote me that "Sherry Rogers says that if we can't tolerate B vitamins, it probably is a mineral deficiency. She suggests treating the minerals first — then adding vitamins if that is the problem — it took her two years to be able to tolerate the vitamins."
• In Looking at the Patient, Han van den Braak mentions that mineral deficiency commonly underlies "liver backlog" where Phase I is more active than Phase II. [See my page Detoxification.]

References

Much of this information was taken from the L-Histidine page of CFS Nutrition (who sell the supplement). References are available there.

My experience

I have problems with all the biological functions listed above.

In blood tests, my SOD was low, cysteine was high & sulfate low (indicating problematic CDO), and several minerals were high. (I’m not absorbing minerals well into other tissues?) On a Quantitative Amino Acid test, my histidine was quite low.

I tried taking a pure histidine powder, from Jo-Mar labs, the same place I get my AK from:

25 mg in 8 oz water along with 75 mg AK (another pure amino acid)

Dizzy, spacey, groggy; moderate headache. Of course I can identify several factors that could have complicated the picture; when I feel stronger I plan to try again.

See also my pages

• The report of my Great Smokies' Liver Detox Profile
• Defect(s) in my Sulfur Metabolism)
• Histamine