Medical News
Scientists think they know why stress
causes hair to grey
Findings could be a breakthrough in understanding how we age
When the
researchers
were able
to stop this
process taking
place, they
could prevent
the mice
developing
grey fur
52
MAY 2020
A
“cure” to grey hair is on its way, thanks to
research that links the premature follicular
condition to stress, possibly leading to a way to
reverse it.
Nobody knows why some people go grey
faster, but stress is often suggested as a link. Now
researchers have found a possible explanation.
The loss of pigment in hair has been shown
previously to be related to the depletion of melanocyte
stem cells. These are essential for hair colour as
they’re responsible for making and depositing pigment
into the hair shaft.
In a new study, Dr Ya-Chieh Hsu, a stem cell
biologist at Harvard University, has found that stress
causes nerves involved in our fight-or-flight response
to pump out a hormone that wipes out the melanocyte
stem cells.
Her research showed that stressed-out mice
release noradrenaline, which causes melanocyte
cells to grow quickly in number and then move away
from the hair, which in turn removes a source of
pigmentation.
When the researchers were able to stop this
process taking place, they could prevent the mice
developing grey fur.
In other research, scientists discovered a
connection between the genes that contribute to
hair colour and those that notify our bodies of a
pathogenic infection, explaining why some people’s
hair may turn grey in response to a serious illness.
When a body is under attack from a virus or
bacteria, the innate immune system kicks into gear.
All of our cells, which have the ability to detect
foreign invaders, then take action by inhibiting viral
replication, activating immune effector cells, and
increasing host defences.
The connection between hair pigmentation and
innate immune regulation was initially a surprise,
according to Dr Melissa Harris, primary author and
assistant professor at the University of Alabama,
Birmingham.
“Genomic tools allow us to assess how all of the
genes within our genome change their expression
under different conditions, and sometimes they
change in ways that we don’t anticipate.
“We’re interested in genes that affect how our stem
cells are maintained over time. We like to study grey
hair because it’s an easy read-out of melanocyte stem
cell dysfunction,” said Dr Harris at the launch of her
study.
Dr Hsu’s research at Harvard suggests that a
similar mechanism is responsible for age-related
greying.
“There are definitely shared responses between
how the melanocyte stem cells respond to stress and
how they respond to ageing,” she told the press after
revealing her findings. “You essentially lose the stem
cell pool in ageing as well.”
A way to stop greying before it begins is certainly
in the cards but could take years before a safe and
effective treatment is developed. A more exciting
area might be how the findings influence science’s
understanding of how stem cell loss throughout the
body contributes to ageing.
GlobalHealthAndTravel.com