In recent years, the scientific community's interest in
stress related cortisol has increased dramatically, along with the stresses of
Westernized day-to day life. The effects of prolonged exposure to stress in our
daily routines results in what we call allostatic load. When there is an
increase in the allostatic load, it can result in receptor desensitization,
tissue damage, and other physical and mental maladies. For these reasons and
more, it is of vital importance to accurately measure short term cortisol
levels caused by both mental and physical stress.
Under conditions of physical and psychological stress the cortisol hormone is released by the zona
fasciculate of the adrenal cortex in the kidneys and periphery- which is
stimulated by an HPA-like axis (Hypothalamus Pituitary Axis) within the hair
follicle. Moreover, it is well documented that blood-borne substances are able
to diffuse from capillaries into the cells of hair follicles and subsequently
become deposited into the hair shaft and fingernails.
Recently it has been
hypothesized that cortisol is incorporated into both hair and nails via similar
cellular mechanisms. In this study, we build upon this hypothesis, theorizing
that cortisol within facial hair is incorporated in the same fashion. Saliva
and serum cortisol levels are subject to major physiological circadian
fluctuations. Additionally, the collection method used with these mediums is
invasive and costly. Alternatively, hair and nail analysis presents a longer
history of cortisol levels, as well as a non-invasive, cost
effective means of collecting samples.
A pilot study by Warnock et al.was the first to find
cortisol in finger nails. The data showed the feasibility of cortisol
assessment in fingernails and significant correlations between cortisol and
DHEA in subjects. A follow-up study done by Izawa et al.confirmed these
results. Yet, to date, no existing study has investigated potential variations
in cortisol levels between fingernails and toenails.
No comments:
Post a Comment