Dr Tara Walker, senior researcher at the Queensland Brain Institute (QBI), said studies on the effect of exercise on brain aging found that levels of protein essential for transporting selenium in the blood rose due to physical activity.
“We’ve known over the past 20 years that exercise can create new neurons in the brain, but we didn’t really understand how,” Dr Walker added.
The research team from the University of Queensland investigated whether selenium supplements can replicate the effects of exercise.
Dr Walker said: “Our models have shown that selenium supplementation can increase neurogenesis and improve cognition in older mice. New neuron generation levels drop rapidly in elderly mice. As in humans. When selenium supplements were given to mice, neuron production increased, reversing cognitive deficits observed in old age.”
Selenium is an essential mineral that is absorbed from soil and water and is found in foods such as cereals, meat and nuts, with the highest levels found in Brazilian walnuts.
The researchers also tested whether selenium has an effect on cognitive decline that sometimes occurs after a stroke, affecting people’s memory and ability to learn.
“Little mice are really good at learning and memory tasks, but after a stroke, they can no longer perform these tasks,” Dr Walker explained. We found that the learning and memory deficits of stroke mice returned to normal when they were given selenium supplements.”
Dr Walker continued that the results opened up a new therapeutic avenue to enhance cognitive function in people who are unable to exercise due to poor health or aging. “However, selenium supplements shouldn’t be considered a complete alternative to exercise, and overusing them can be bad for you. A person who gets a balanced diet of fruits, nuts, vegetables, and meat usually has good levels of selenium. But in older adults, especially those with neurological diseases, selenium supplements can be helpful.”