Two important new publications have started to uncover the precise biological links between psychological stress, greying and hair loss.
Recent reports of women experiencing alarming, post-Covid hair loss (Women recovering from Covid tell of distress at losing clumps of hair, Sunday Times 25th April, 2021) remind us, again, that hair growth is sensitive to both physical and psychological stress. Whilst the precise links between Covid and excessive hair shedding still need to be fully investigated, experts seem to agree that the stress and trauma of having Covid could be a major factor in some patients.
The idea that psychological stress can affect premature greying and hair loss is not new, but new studies are starting to uncover the biological mechanisms through which this may occur.
Zhang et al, for example, have discovered that overactivity in the sympathetic nervous system and over-production of noradrenaline, leads to the overstimulation of melanocyte stem cells (Zhang, B., et al. Hyperactivation of sympathetic nerves drives depletion of melanocyte stem cells. Nature 577, 676-681, 2020). This over-stimulation, the authors argue, leads to a faster depletion of the stem cell reservoir in the bulge region of the follicle. This depletion leads to faster greying.
Just recently, Choi, et al, have uncovered the links between stress hormones produced by the adrenal glands, and the activation of hair follicle stem cells (Choi, et al. Corticosterone inhibits GAS6 to govern hair follicle stem-cell quiescence. Nature 592, 428-437, 2021). Their work shows that stress hormones are actually detected by dermal papillae cells. These cells then release a protein that controls hair follicle stem cells, and so, hair growth.
Both these new discoveries open exciting new avenues for treating premature greying and hair loss in the future. However, for now, we are probably well advised to respect the destructive power of psychological stress and take good care of our mental wellbeing if we want to protect our bodies and our hair.
For more information about hair research contact us at www.triprinceton.org