The incredible complexities of the human body, health, lifestyle, and increasing stressors in our troubled world, can give rise to the onset of scalp hair thinning. The ‘usual suspects’ are thyroid disturbance, diabetic states, nutrient deficiency, or ‘stress’.
A cause which is often over-looked is the crucial role of adrenal gland influence to disrupt or enhance hair follicle activity.
Adrenal glands and their function:
The adrenals (1) are two triangular-shaped endocrine glands located atop each kidney. The gland is comprised of two distinct parts: the inner medulla and the outer cortex. Both produce specific hormones; the cortex is further divided in to three zones – each zone also produces particular hormones as required by the body.
Cortisol (CC) is the major glucocorticoid (steroid hormone) produced in the adrenal cortex. Cortisol is a key stress response hormone – essential for carbohydrate, protein and fat metabolism, anti-inflammatory tasks, blood glucose regulation, and appropriate immune system function. Cortisol is essential for Triiodothyronine (T3) thyroid hormone ‘expression’ because it up-regulates nuclear T3 receptors within the cells.
Other steroid hormones produced from the cortex are Aldosterone, DHEA (2) and other weak androgenic steroids.
The principal hormones arising from the medulla are Adrenaline and Noradrenaline – the so called ‘fight or flight’ hormones. Adrenaline and Noradrenaline are stimulated in response to physical or emotional stress as an additional (short-term) energy and coping resource for the body.
Adrenal influence on hair growth:
Adrenal insufficiency (3) can result in thinning scalp hair in women. Low adrenal functioning gives rise to excess histamine release, chronic inflammation, or a chronic anxiety state due to poor stress response. Those with environmental or food allergies, respiratory or autoimmune disease are considered most at risk.
Medical researchers at Harvard University, USA (4) found persistent physiological stress can induce inactivity in follicle stem cells to prolong the resting phase so new hair growth is not initiated.
The scientists concluded that elevated Cortisol has an indirect adverse effect on follicle stem cell activity – and as even a baseline level of circulating Cortisol is believed to be a key regulator in stem cell latency – when stress hormone is surging, stem cell activity is further blunted, and anagen phase hair regeneration does not occur.
Cortisol exerts a precise influence on the cells of the dermal papilla, (which lies beneath the hair follicle) by inhibiting these cell’s secretion of the stem cell-activating molecule Gas-6. When researchers exposed the hair follicle stem cells to Gas-6, it precipitated a rapid transition out of the resting phase and into regrowth resumption.
The changing hormonal milieu at menopause is a common reason for scalp hair thinning – and declining Testosterone (TT) levels is a known factor. Low Testosterone is strongly associated with low DHEA (5), so maintaining optimal adrenal function (where possible) as we age should be at the forefront of any medical evaluation. The adrenals may be low priority to a busy health practitioner, but these little glands exert an influence on health, mood and well-being far beyond their size.
Copyright Anthony Pearce 2022.
- Also referred to a supra-renal glands
- Dehydro-epiandrosterone: weakest, most abundant male hormone (termed: androgen) produced by the adrenal glands in both men and women. DHEA is also considered a ‘marker for adrenal reserves’. Cortisol has an inverse relationship with DHEA: when Cortisol is elevated, DHEA levels are low.
- As characterised by low Cortisol and/or DHEA levels in blood, saliva or urine excretion.
- Dr. Sekyu Choi and Professor Ya-Chieh Hsu whose work and research paper I acknowledge.
- Nicotine – found in cigarettes and most vapes inhibit the production of the enzyme – 11-beta-hydroxylase – essential in the making of DHEA. There is a strong correlation between low DHEA and the onset of diseases such as cancer, heart disease, allergies, diabetes, autoimmune conditions, and osteoporosis. DHEA production should peak around 20-25 years of age.
See other articles at this website: The Stress – hair loss correlation and The Hormones: Melatonin, Cortisol and DHEA-s.