You probably know that exercise boosts brain function, but did you know that exercise can literally change the structure of our brains? Although these structural changes may not be visible to us, they can help us protect and preserve brain health and function throughout our lives.
Exercise has been shown to prevent the loss of total brain volume (which can lead to lower cognitive function), as well as preventing shrinkage in specific brain regions associated with memory. For example, one magnetic resonance imaging (MRI) scan study revealed that in older adults, six months of exercise training increases brain volume.
Another study found that shrinkage of the hippocampus (a brain region essential for learning and memory) in older people can be reversed by regular walking. This change was accompanied by improved memory function and an increase of the protein brain-derived neurotrophic factor (BDNF) in the bloodstream. BDNF is crucial for healthy cognitive function due to its roles in cell survival, plasticity (the brain’s ability to change and adapt from experience), and function.
Because our nervous tissues are in constant need of oxygen to function and survive, we have a lot of blood flow in our brains. In fact, some 15 percent of the body’s entire blood supply goes to the brain. With regular exercise, we increase the growth of new blood vessels in the brain regions where neurogenesis occurs, providing the increased blood supply that supports the development of these new neurons.
Exercise also improves the health and function of existing blood vessels, ensuring that brain tissue consistently receives adequate blood supply to meet its needs and preserve its function.
As described by The Conversation UK, more and more research is focusing on microglia, the resident immune cells of the brain. Their main function is to constantly check the brain for potential threats from microbes or dying or damaged cells, and to clear any damage they find. Microglia become less efficient as we age, but recently, new research shows that exercise can reprogramme these microglia in the aged brain. As a matter of fact, exercise was shown to make the microglia more energy-efficient and capable of counteracting neuroinflammatory changes that impair brain function. Exercise can also modulate neuroinflammation in degenerative conditions like Alzheimer’s disease and multiple sclerosis.
From the archive: This popular healthy living story was originally published on The Optimist Daily November 18, 2020.