It would be the rare individual concerned about hair loss that hasn’t been told at least once it’s being caused by ‘stress’. Often a platitude and sometimes crudely correct, but what does the term mean?
‘Stressed, stress-out or under stress’ usually means that the circumstances of one’s internal or external milieu is causing hormonal changes – particularly surges in adrenal hormones – to produce feelings of unease in the individual.
Hair follicle activity:
Human hair follicles are one of the most metabolically active tissues due to continuous cycles of stem cell regeneration throughout life. Unlike dogs or other animals, humans don’t undergo distinct moults across the seasons, rather each hair follicle independently cycles between growth, rest and regrowth – these phases driven by hair follicle stem cells.
Within the anagen (growth) phase, hair follicle stem cells are stimulated to regenerate follicle activity, and the hair grows outward.
Catagen-Telogen is the resting-falling phase of follicle transition where stem cells are dormant and the hair from that follicle is ultimately shed. Noticeable thinning of scalp hair density will be apparent if more than 20% of scalp hair is shed and follicle stem cells remain inactive, so no tissue regeneration occurs.
How ‘stress’ influences the hair follicles:
Medical researchers at Harvard University, USA (1) found that persistent physiological stress can induce inactivity in follicle stem cells to prolong the resting phase so (new) hair growth is not initiated.
Cortisol and Adrenaline are the predominant adrenal hormones upregulated in response to internal stress or perceived external threats. 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 – so when stress hormone is surging, stem cell activity is further blunted, and anagen phase hair regeneration does not occur.
Researchers also found 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 (2). When hair follicle stem cells were exposed to Gas-6 it precipitated a rapid transition out of the resting phase and into regrowth resumption.
Most interestingly, this occurred in hair follicles in their normal resting phase as well as those dormant under the influence of increased stress. Further research is now underway to ascertain if the Gas-6 pathway can be manipulated for its potential in activating stem cells to promote hair growth, and to study whether other stress-related body disturbance is associated with Cortisol’s impact on regulating the Gas-6 molecule.
Cortisol: its importance and what elevates it:
Cortisol (CC) is the major glucocorticoid (steroid hormone) produced in the adrenal cortex of the adrenal glands. 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 our active thyroid hormone (Triiodothyronine – T3) ‘expression’ because it up-regulates nuclear T3 receptors within the cells. Cortisol has a quantitative effect by increasing intra-nuclear T3 receptor density (Van Zanden: 2017).
Elevated Cortisol may be the result of:
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- A severe shock or emotional stress which we would all recognise (3)
- Unrelenting emotional, mental or physical abuse in a violent or dysfunctional relationship.
- A toxic, bullying or ‘gaslighting’ workplace resulting in constant stress or tension.
- The grinding down effects of a fast-paced lifestyle or work environment where you are under constant pressure to work long hours, meet deadlines or sales figures etc.
- Senior secondary and university students are at higher risk of stress hormone disturbance – sometimes leading to adrenal fatigue – due to the pressure and long hours of study (Van Zanden: 2017).
- Physical disease such as Cushing Syndrome, pituitary or primary adrenal gland tumors.
- The prolonged taking of Corticosteroid (prescription) medication (5) in the treatment of autoimmune or other disease.
- Disturbance of (synthetic) oestrogens causing a retention of copper leading to elevated Cortisol (4). This is seen in about 30% of women taking contraceptive or HRT therapy. Pregnant women will often exhibit an elevated copper during their term of pregnancy. Wilson’s syndrome results in copper being retained in the body’s organs which may result in elevated Cortisol in some individuals.
- Chronic mood disturbance or mental illness such as bipolar disorder – particularly manic episodes.
The effects of elevated Cortisol on thyroid function:
- Chronically elevated stress mimics symptoms of thyroid dysfunction: fatigue, ‘brain fog’, poor motivation, and weight gain.
- Elevated Cortisol has a blocking effect on Thyroid stimulating hormone (TSH) signaling from pituitary gland to the thyroid gland.
- Reduces hepatic (liver) conversion of inactive T4 to active T3 thyroid hormone.
- Inhibits cell uptake of T3.
- The inflammatory action of Cortisol has a degrading effect on the linings of the gut wall, which may lead to ‘leaky gut’ – the precursor of autoimmune disease.
What arguably excited the Harvard researchers the most was that our adrenal glands – at least in part – determine skin appendage stem cell stimulation and activity rather than a totally localised (skin) regulator.
We all eagerly await the development of Gas-6 into an approved adjunct pharmaceutical medication for stress-related scalp hair thinning, or even to naturally block the physiological effects of stress itself.
Copyright – Anthony Pearce 2021 (revised: September 2024).
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- Dr. Sekyu Choi and Professor Ya-Chieh Hsu whose work and research paper I acknowledge.
- Harvard.edu: 2021
- A death or news of severe illness in the family, unexpected relationship break down, accident or debilitating injury, unexpected financial penury or sudden homelessness etc.
- Copper dominance has an absorption-inhibiting effect on zinc, iron, B12 and other nutrients/trace elements. It both depletes and degrades the fragile nutrient Vitamin C and may cause ‘inexplicable’ rises in Vitamin A, Insulin and Cortisol.
- Elevated Cortisol (medication-induced Cushing syndrome) can occur from hi-dose oral corticosteroid medications – such as prednisone – taken over extended periods of time. Oral corticosteroids are often prescribed to treat inflammatory or autoimmune diseases: rheumatoid arthritis, lupus or acute asthma. They are also often prescribed in post-transplant procedures to help prevent organ or tissue rejection. Repeated injections of corticosteroids for chronic bursitis, joint or back pain has been known to result in hypercortisolaemia as have inhaled corticosteroids for asthma or chronic lung disease. (Mayo Clinic, USA: 2021)