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.
There is also a synergistic relationship between Zinc + stomach acid (HCL). Sufficient HCL production is required to absorb Zinc, whilst good Zinc levels are required for HCL production.
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 & Psoriasis skin scaling conditions
- As a natural 5-AR inhibitor, zinc is known to inhibit the up-conversion of Testosterone (TT) to Dihydrotestosterone (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 & 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.****
Zinc deficiency in (female) hormonal therapy:
A percentage of women taking oral contraceptive (OCP) or hormonal therapy (HRT) will over time exhibit suppressed zinc absorption & eventual zinc deficiency.
This occurs because the synthetic Oestrogen from the oral contraceptive/ hormonal therapy cannot be metabolised by the woman’s body, and is RETAINED in the body.
This in turn has a ‘retention effect’ on Copper (Cu) levels. Rising Copper causes further Oestrogen retention – leading to yet more elevated Cu levels.
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.
It’s this ‘across the board’ disruption in nutrient and hormonal balance that ultimately presents as noticeable thinning of scalp hair density, tiredness & other clinical signs.
A noted anomaly of zinc deficiency seen in Trichology is dry, fragile/brittle hair but withan accompanying greasy/oily or scaling scalp. Other deficiency signs include poor wound healing, ‘white spotting’ on fingernails, lethargy, easy bruising – and dry, scaly facial acne as zinc deficiency becomes more severe.
The usual Zinc reference rage is 10-20umol/L; ‘target’ is to be 17-20umol/L. Zinc toxicity may occur at levels of 40-50umol/L.
Iron, Copper & Zinc are known to antagonise & potentially suppress the others absorption, unless they are a particular form of Zinc & Copper known as ‘Picolinate’.
The Zinc ‘absorption paradox’:
There is a crucial & synergistic relationship between Zinc + stomach acid (HCL). Sufficient HCL production is required to absorb Zinc, whilst good Zinc levels are required for HCL production (Chan: 2011).
A simple + inexpensive way to stimulate digestive enzyme production (especially stomach acid) is to take 5ml APPLE Cider Vinegar immediately before each meal; add to plain apple juice, still or sparkling water. You may also use other ‘bitters’ such as ‘double expresso’ (short black) coffee, ‘Swedish’ bitters or lemon juice.
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 December 2019)