the times | Tuesday October 20 2020 1GM 21
News
A daily swim in cold water could help
guard the brain against dementia,
scientists have suggested.
Researchers looked at 40 people who
swam in the unheated waters of
Parliament Hill Lido in north London
through the winter months.
Those who had been taking dips for
at least the past ten years were found to
have elevated levels of a “cold-shock”
protein that may protect against
degenerative conditions.
Professor Giovanna Mallucci, centre
director of the UK Dementia Research
Institute at Cambridge University, said
the findings could help to develop new
treatments to delay dementia. “Only
swimmers who got cold had raised
levels of this protein,” she said. The aim
is to find a drug that has the same effect.
Professor Mallucci and her teamCold-water swimming could
help to keep dementia at bay
were initially intrigued by changes that
occur in the brains of mammals that
hibernate, such as hedgehogs and
bears. As these creatures slumber
through the winter, connections
between brain cells, known as synapses,
are broken. Similar disconnections in
the human brain appear to be linked to
symptoms associated with dementia,
such as memory loss, confusion and
mood swings. But while dementia is
irreversible, hibernating animals are
able to restore their brain connections
when spring arrives.
The Cambridge team had previously
found that a “cold-shock” protein
known as RBM3 appeared to play an
important role. In mice they mimicked
the biology of hibernation, during
which the core body temperature
drops, by cooling the animals for short
periods in a fridge.
Mice do not naturally hibernate, butthe scientists found that the synapses
in their brains still dismantled on cool-
ing and regenerated on warming up
again. When the experiment was re-
peated with mice bred to reproduce fea-
tures of Alzheimer’s the animals were
unable to regenerate lost connections.
They also had lower levels of RBM3.
When levels of the protein were
artificially boosted, this alone was
enough to protect the mice and prevent
synapse and brain cell depletion.
Other research has found that
patients who have a brain injury can
benefit from being cooled; it is possible
that RBM3 also plays a part in those
cases.
The latest research, which is yet to be
peer reviewed, looked at whether
RBM3 might also occur in humans who
often experience hypothermic state.
The scientists compared the blood of
swimmers who regularly took chillyswims in the Parliament Hill Lido with
a group doing Tai Chi outside.
Veteran swimmers had elevated
levels of RBM3. While they swam, all of
them became hypothermic with core
temperatures as low as 34C. None of
the Tai Chi group showed these higher
RBM3 levels or experienced low body
temperatures.
“We have heard these anecdotal
stories of people being pulled out of
frozen rivers and being reanimated,”
Professor Mallucci said. “And we use
cooling to about 34C-35C for babies
born with low oxygen to their brains,
for people with head injuries, for stroke.
It’s used routinely to protect the brain
but nobody knows how it really works.
The discovery of this protein is a pretty
good candidate.”
The challenge now is to reap the
benefits without having to get wet,
leading article, page 31Rhys Blakely Science Correspondent
Catching up
with friends
is best tonic
for the brain
Rhys Blakely
Doctors should consider prescribing
get-togethers with friends and family to
ward off dementia, researchers suggest,
after finding that older people with bus-
ier social lives have healthier brains.
The study of nearly 300 participants,
with an average age of 83, is the first
using a sensitive brain scan called
Diffusion Tensor Imaging MRI. It
measures the integrity of regions of
brain cells thought to become active
during social interaction, which also
appear to be affected by dementia.
Cause and effect still need to be dis-
entangled: the study could not show
that greater social engagement kept
these brain regions healthy. It may be
that having a healthy brain results in a
better social life.
However, the researchers said that
“prescribing” social activities could
benefit older adults at danger of cogni-
tive decline, much in the same way as
urging somebody to exercise can help
to prevent diabetes or heart disease.
Cynthia Felix, of Pittsburgh Univers-
ity, who led the study in Journal of
Gerontology, said: “I believe our find-
ings are particularly important right
now, since a one-size-fits-all social iso-
lation of all older adults may place them
at risk for conditions such as dementia.”
High scores were awarded to people
who participated in activities such as
board games and going to the cinema.
Points were also given for attending
classes and lectures, church or other
community activities, getting together
with children, friends, relatives or
neighbours and volunteering.
Researchers found that even moder-
ate social activity, such as seeing friends
once a week, appeared to be beneficial.
Another study in The Lancet Planet-
ary Health suggests a link between air
pollution and an increased risk of neu-
rological disorders. Researchers looked
at 63 million adults in the US and found
for each 5mcg per cubic metre of air
increase in annual exposure to PM2.5, a
type of fine particulate air pollution,
there was a 13 per cent increased risk of
hospital admissions for Parkinson’s and
Alzheimer’s diseases.
LEON NEAL/AFP VIA GETTY IMAGES; TOLGA AKMEN/AFP/GETTY IMAGESRegular winter swimmers at Parliament Hill Lido in north London were found to have higher levels of a protein that may protect against degenerative conditions