Zinc – the hair (+ thyroid) ‘liberator’

For many decades now the heavy metal zinc has been used in the treatment of scalp hair loss & inflammatory skin conditions.

Zinc is an essential co-factor for over 300 ‘metalloenzymes’* in the human body, including those which exert essential functional activities within the hair follicle.

Zinc is also critical for cell DNA stability & repair – a crucial parameter in hair biology as the “epithelial hair matrix is one of the most proliferating & damage-sensitive tissues in the mammalian organism” (Plonka et al: 2005). Plonka’s study also found zinc inhibited chemotherapy-induced alopecia and accelerated the re-growth of normally-pigmented hair shafts** (Plonka et al: 2005).

Symptoms of Zinc deficiency:

  • The seeming paradox of a greasy/oily scalp, but often with dry, brittle hair. This hair/scalp anomaly is sometimes accompanied by a flaking, irritated or pustular scalp.
  • White spotting seen on the fingernails; a dry, scaly acne of the forehead and face.
  • Further signs may include noticeable tiredness, poor wound healing, and the skin bruises easily.
  • Scalp hair loss may present as a diffuse thinning over the entire scalp, with an accompanying androgenic ‘pattern’ hair appearance.

Some of the many benefits of Zinc:

  • Facilitates the binding of proteins via structures termed ‘zinc fingers’; vital co-factor for protein replication.
  • Crucial support in cellular growth & repair.
  • Aids synthesis & secretion of growth hormone from the Pituitary gland.
  • Reduces the oxidative effects of electromagnetic radiation (EMR/EMF) – an ever-increasing concern in our hi-tech world due to EMR’s suppressive effects on the body’s diurnal rhythm (Bediz: 2006).
  • Supports hormonal balance & helps stabilise sebaceous gland activity.
  • Is a recognised treatment in hormonal skin conditions such as folliculitis, acne, hirsutism as well as seborrhoeic dermatitis and psoriasis skin scaling conditions
  • As a natural 5-AR inhibitor, zinc is known to inhibit the up-conversion of Testosterone (TT) to Dihydro-testosterone (DHT) in androgenic alopecia.

Zinc’s main contributions to thyroid homeostasis are:

  • The synthesis of Thyrotropin Releasing Hormone (TRH) – produced by the Hypothalamus to stimulate production of Thyroid Stimulating Hormone (TSH) – also known as Thyrotrophin.
  • A crucial catalyst in the binding and activation of the active thyroid hormone Triiodothyronine (T3) to receptors on the cell nucleus.
  • Where there is a ‘corruption of thyroid conversion competency’ (Lee: 2007), supra-therapeutic doses of Zinc and Selenium will help re-direct T4 conversion pathway away from Reverse T3 (rT3) back to T3 ‘active’ thyroid hormone. RT3 is ‘de-activated’ T4.
  • Zinc deficiency*** is thought to contribute to poor thyroid hormone conversion – and deficiency diminishes healthy genetic expression of thyroid hormone.

A refractory zinc deficiency may result from inadequate protein availability (Baratosy: 2006). The amino acid (Tyrosine) – derived from protein – is a foundation of thyroid hormone production.

Worldwide zinc deficiency is conservatively estimated to be at least 25% (Underwood: 2013). Populations of less developed nations – particularly the children & elderly – are more at risk due to malnutrition, diet or food restriction – or diarrhoea from its many causes.

An Australian National Nutrition Survey (1995) of community & nursing home residents found between 20-85% consumed less than 2/3 of the recommended zinc RDI.****

Common causes for Zinc deficiency:

  1. A diet not containing sufficient zinc-rich foods to achieve minimum RDI. Foods such as lean red meat, shellfish, dark chocolate, legumes, nuts and seeds are some of the best dietary sources.
  2. Women taking contraceptive (OCP) or hormonal therapy (HRT) can over time exhibit suppressed zinc absorption & eventual zinc deficiency.

This occurs because the synthetic Oestrogen from contraceptive/ hormonal therapy cannot be metabolised by some women and is retained, causing a retention effect on Copper (Cu). Once copper is in excess and too dominant in relation to zinc, it can exert what Baratosy (2005) describes as an ‘anti-nutrient’ or toxic metal influence.

High copper levels restrict the absorption and utilisation of zinc (particularly) – as well as iron, magnesium, Vitamins B3, 5, and 6, Vitamins C and E, and certain trace elements.

  1. Taking Protein Pump Inhibitors (PPI’s) for oesophageal reflux. PPI’s block the action of stomach parietal cells to secrete stomach acid (HCL), but HCL and zinc have a synergistic relationship: sufficient HCL is required to absorb zinc whilst good zinc levels are required for HCL production (Chan: 2011).
  2. Protracted stress, anxiety or other mood disturbance is known to reduce stomach acid, gut nutrient absorption and anorexia (loss of appetite) in some sufferers.
  3. Health conditions such as Coeliac or inflammatory bowel disease, numerous chronic disease conditions, diabetes or alcoholism. Those with Pyrrole disorder or Autism tend to be zinc deficient or require regular supplementation.
  4. Drinking copious amounts of tap water from the (copper) pipes in a new home may cause low zinc levels over time due to the antagonistic effects of copper on zinc.

The usual Zinc reference rage is 10-20 umol/L; ‘target’ is to be 17-20 umol/L. Zinc should also be in a 1:0.8 in relation to Copper Zinc toxicity may occur at levels of 40-50 umol/L.

Zinc and copper directly compete for absorption at the gut interface, so if one (usually copper) is elevated – the other (zinc) is habitually low or deficient. When pathology testing reveals BOTH zinc and copper to be deficient – this usually indicates malabsorption by the gut.

The challenge of oral zinc therapy for hair loss is ‘optimal dosing’ will enhance follicle hair growth, but excessive or prolonged administration can result in a repressed hair growth (anagen) cycle or even be a cause for hair loss.

Similar to other biologically-active agents or pharmaceutical drugs, zinc follows a characteristic bell curve: a sub-therapeutic dose does not provide the desired pharmacological outcome; an excessive or prolonged dosage may have a retrograde or even harmful effect – whilst a ‘beneficially-optimal’ amount will ensure a pharmacological dosage-response relationship (Chan: 2007).

*Enzymes containing a metal ion in their structure.

**In laboratory mice studies

*** As well as Vitamin D & Selenium

****National Health & Medical Research Council (Dietary Guidelines for older Australians – 1999

Copyright Anthony Pearce (2016 – Revised July 2021)

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