An Australian study has found that selenium—a mineral found in many foods—could be the key to a healthier mind, as experiments show that it can reverse the decline in brain function from poor health or old age.
Selenium is a powerful antioxidant found in meat, tuna, halibut, sardines, salmon, organ meat, eggs, and nuts, with the highest levels found in Brazil nuts.
Researchers from the Queensland Brain Institute (QBI) discovered that physical exercise activates the mineral’s benefits, as increased activity facilitates a protein key to transporting selenium into our blood.
Lead researcher Tara Walker said this is the reason why exercise creates new neurons in the brain, boosting learning and memory.
“We’ve known for the last 20 years that exercise can create new neurons in the brain, but we didn’t really understand how,” Walker said.
The scientists sought to help people with low mobility also obtain the same benefits of the mineral, and tested to see whether selenium supplements could replicate the effects of exercise.
Their models showed that it increased neuron generation and improved the brains of elderly mice.
“When selenium supplements were given to the mice, the production of neurons increased, reversing the cognitive deficits observed in ageing,” Walker said.
“The levels of new neuron generation decrease rapidly in aged mice, as they do in humans.”
They did further tests that examined the effect of selenium after a stroke, which can affect one’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,” Walker said.
“We found that learning and memory deficits of stroke-affected mice returned to normal when they were given selenium supplements.”
However, she cautioned against people becoming too reliant on the mineral.
“Selenium supplements shouldn’t be seen as a complete substitute for exercise, and too much can be bad for you,” she said.
If a person is not at high risk for a deficiency, there is no need to take selenium supplements, according to the Harvard School of Public Health.
While deficiency of selenium can create a lot of damage, toxicity can also lead to other health problems from muscle tremors, hair loss, to more severe reactions such as a heart attack or kidney failure.
“A person who is getting a balanced diet usually has good selenium levels. But in older people, particularly those with neurological conditions, selenium supplements could be beneficial,” Walker said.
