38 | New Scientist | 22 February 2020
the chronic stress of a bad marriage had
leakier guts than less hostile couples. But the
relationship works in the other direction too.
Mice given “good” bacteria called Lactobacillus
rhamnosus for 28 days before facing chronic
social stress were protected against some
stress-induced behaviours.
Although there are still major gaps in our
understanding of the complex dialogue
between gut and brain, there is substantial
evidence that therapies aimed at changing the
balance of microbes in the gut, and also what
we eat, could have an exciting role in protecting
us against – even reversing – the negative
consequences of stress.Cool profile
All this makes it clear that people who
seem immune to stress are blessed with
a combination of attributes. We still don’t
have a scientific way to identify the ideal
stress-resilient profile, but Belgian special
forces are working on it. In one study, they
randomly subjected half their wannabe
recruits to a highly stressful prisoner of war
exercise, while the others undertook mundane
weapons training. Researchers wanted to
compare their hormone profiles and any
deterioration of cognitive functions in later
tests to gauge the effects of stress. The aim is to
use these markers in future selection exercises
to identify candidates likely to struggle in
stressful situations. They could also be used
to monitor soldiers in the field and measure
the impact of training on stress resilience.Helen Thomson is a consultant for
New Scientist and author of
Unthinkable: An extraordinary journey
through the world’s strangest brainsSuch a resilience profile would be useful
for any employer needing to recruit people
for stressful jobs. But what about the rest of
us just wanting to cope better when we miss
a train or attend an interview? Of course,
there are plenty of ways to de-stress. Regularly
listening to music seems to alter many
chemicals involved in our stress response,
and lowers blood glucose, making challenges
seem less stressful. Exercise also boosts
hormones that can act to lower perceived
stress. Meditation, meanwhile, has a longhistory as a stress reliever, and research shows
that just eight weeks’ practice can trigger brain
changes related to better emotional control
and stress resilience that are similar to those
seen in long-term meditators.
In future, we may even be able to inoculate
ourselves against stress (see “How to make a
stress vaccine”, page 36). For now, James
Murrough at the Mount Sinai Hospital in New
York, who is working on this, recommends
good mental hygiene. “This is about making
sure you have the right resources in place to
help you cope,” he says. Alongside regular
exercise, sufficient sleep and time out to relax,
you should also cultivate your social networks.
“You have to put the work in to make sure your
social ties are healthy so that when stress
occurs you can rely on them,” says Murrough.
“Data suggests that is your best bet for building
resilience against daily stress.”
But don’t forget that a little stress isn’t a
bad thing. In fact, it might just boost your
cognition, if research on rats is anything to
go by. A team led by Daniela Kaufer at the
University of California, Berkeley, exposed
rats to a stressful environment for 3 hours
while tracking the development of new
neurons in their hippocampus, a brain region
responsible for memory. Intriguingly, these
cells proliferated more in the stressed animals
than in a control group. But the real surprise
was the long-term effect. Rats that had been
stressed did better in cognitive tests, even
weeks later, specifically engaging their new
neurons to help with these tasks. It isn’t yet
possible to do this kind of study in humans,
but we do know that new neurons allow us
to learn better. “We think there are many
similarities between animals and humans,
but we’re not quite there yet,” says Kaufer.
Nevertheless, she is often asked what the
perfect amount of stress is. “It’s impossible
to give you an exact figure,” she says. “The
ideal amount is going to be different from
one person to another.” What someone finds
invigorating, another may find daunting. On
top of that, what feels stressful one day might
not feel so another. “But if there is beneficial
stress, then it’s likely to be something you can
pinpoint yourself,” says Kaufer. “It’s probably
the difference between the stress that paralyses
you and the stress that you can push through,
that makes you feel really great afterwards.” ❚Stress and anxiety are often
intertwined in our minds,
but they refer to different
things. Stress is a biological
process that results in a
series of chemical reactions
within our body and brain
that help us focus on a
challenging situation and
adapt our behaviour (see
main story).
Stress can be a positive
or negative experience
and although you may feel
stressed for a few seconds,or a few weeks, it normally
occurs within a discrete
time frame.
Anxiety can be triggered
by stress, but it is a feeling
that tends to hang around
after the initial threat or
challenge disappears.
If anxiety occurs most
days for longer than six
months, it is known as
generalised anxiety
disorder. This condition
affects around 6.8 million
adults in the US each year.The difference between
stress and anxietyIt doesn’t take long to get
big stress-busting effects
from meditationFR
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