Updated: Apr 5
With Dr Tara Walker, neuroscientist
I can hear you now. I don’t run, or I am too old to run or the classic, I want to protect my knees, and the list goes on. This is exactly what I use to think. Exercise is the one thing shown across several studies to help the brain produce new cells or neurons, also called neuroplasticity. Dr Tara Walker, a neuroscientist, at the Queensland Brain Institute has spent the last 20 years trying to work out how running helps the brain’s memory centres function more effectively. In a recent high-profile journal, she and her colleagues published a remarkable discovery, that a trace element, selenium, they found in the blood leads to the production of more brain cells in the part of the brain, called the hippocampus, that helps us learn new things and remember old ones. Selenium can be found in nuts, grains and fresh fruit and vegetables and particularly in brazil nuts. For example, one brazil nut a day is enough. Having brazil nuts does not help and can lead to problems.
As much as we might like to take a supplement rather than run or exercise. There will never be enough benefits conferred from supplements that are equivalent to exercise. The main reason is that exercise gets the heart pumping blood and oxygen to nearly every place in the body and keeps the heart and body fit. It activates skeletal muscle that helps with insulin sensitivity and diabetes. The benefit list goes on and on. There is a lot of debate about how much exercise is the right amount. Can you do too much exercise? The right prescription of exercise has not been worked out. But there is no doubt that some form of movement everyday matter to stay healthy. For those of us not able to walk or run, then we can move our arms. If this is not the case, then we can learn something new, like a language, or meet new people. The brain needs a lot of novelty, and learning to stay healthy.
Dr Walker has gone one step further than many of us and that is to work out through experiments how exercise improves factors in the blood that leads to changes in the brain. This was ground-breaking research. The most surprising discovery was just how much memory is improved with aging from adding exercise and the supplement, selenium. This leads to the idea that what you eat matters to getting the brain benefits from exercise.
Dr Walker also didn’t think she could run. She was a swimmer when she was young. But by taking small steps, she slowly built up to running. She thought a 10km fun run was her limit, but then came the half and full marathon and now she is training for a 60 km trail run in the mountains in Brisbane. While she runs, her best ideas come, and this is how she decided to examine the blood of animals exercising to discover that proteins related to selenium are changed. This was the beginning of an 8-year project to demonstrate how exercise changes the brain. It takes a village running together to make breakthroughs in neuroscience. What amazing work, and how lucky are we to interview her on episode #80 of the Thriving Minds podcast.