A natural mineral found in many foods – selenium – could help reverse the cognitive impact of stroke and boost learning and memory in ageing brains, new research has found.
Selenium is found in foods including grains, meat and nuts, with the highest level found in Brazil nuts. It is an essential trace mineral absorbed from soil and water.
The mice study, from Queensland Brain Institute, 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,” said Dr Tara Walker, lead researcher in the study.
“Our models showed that selenium supplementation could increase neuron generation and improve cognition in elderly mice.
“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.”
The research team 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, vegetables and meat usually has good selenium levels.
“But in older people, particularly those with neurological conditions, selenium supplements could be beneficial.”
