Brain food
Selenium is a mineral found in foods including meat, grains and nuts.
Selenium – a mineral found in many foods – could reverse the
cognitive impact of stroke and boost learning and memory in ageing brains,
according to University of Queensland research.
Queensland Brain Institute (QBI)
lead researcher Dr Tara Walker said studies
on the impact of exercise on the ageing brain found levels of a protein key to
transporting selenium in the blood were elevated by physical activity.
“We’ve known for the last 20 years that exercise can create
new neurons in the brain, but we didn’t
really understand how,” Dr Walker said.
The research team investigated whether dietary selenium supplements could replicate the effects of exercise.
“Our models showed that selenium supplementation could increase
neuron generation and improve cognition in elderly mice,” Dr Walker said.
“The levels of new neuron generation decrease rapidly in aged
mice, as they do in humans.
“When selenium supplements were given to the mice, the
production of neurons increased, reversing the cognitive deficits observed in
ageing.”
Selenium is an essential trace mineral absorbed from soil and
water and is found in foods such as grains, meat and nuts, with the highest
levels found in Brazil nuts.
The scientists also tested whether selenium would have an impact
on the cognitive decline sometimes experienced following stroke, which can affect people’s memory and
ability to learn.
“Young mice are really good at the learning and memory tasks,
but after a stroke, they could no longer perform these tasks,” Dr Walker said.
“We found that learning and memory deficits of stroke affected
mice returned to normal when they were given selenium supplements.”
Dr Walker said the results opened a new therapeutic avenue to
boost cognitive function in people who were unable to exercise due to poor
health or old age.
“However, selenium supplements shouldn’t be seen as a complete substitute
for exercise, and too much can be bad for you,” she said.
“A person who is getting a balanced diet of fruits, nuts,
veggies and meat usually has good selenium levels.
“But in older people, particularly those with neurological
conditions, selenium supplements could be beneficial.”
The research was first published in Cell Metabolism. (DOI:10.1016/j.cmet.2022.01.005).