Multiple factors influence cognitive decline as an individual ages, such as hormones, exercise levels, insulin resistance, and sleep quality over time, to name a few. I have said in the past few years that if I had to choose between losing my physical body and losing my mind, I would choose to lose my physical body. I understand that many reading this are seeking goals to look their best, feel their best, or perform their best; while those are great goals, the fact that you are even participating in some sort of exercise is improving your cognitive health for aging. Whether you exercise to improve your cognitive health or your physical body as your primary goal, here are a few factors to consider regarding how exercise improves your cognitive health as you age.
An article published in 2019 called “Physical Activity and muscle-brain crosstalk” by B.K. Pedersen discusses how exercise can improve brain health.
At the basic level, when an individual exercises, the muscle releases proteins called myokines that positively impact brain function, neurogenesis, and cognition. In the brain, there is what is called Brain-Derived Neurotrophic Factor (BDNF), and exercise enhances BDNF production, which supports memory, learning, and neuroplasticity, having its greatest impact on the hippocampus which is the area that supports memory and learning. When an individual exercises, a myokine called Cathepsin B can cross the blood-brain barrier and increase BDNF, while another myokine called FNDC5/Irisin is released that stimulates BDNF production in the hippocampus. This means that exercising in general will release myokines that increase and stimulate BDNF in the brain, leading to the increase in hippocampus volume that is crucial for memory and learning, which is shown to reduce/slow the risk of cognitive decline as we get older.
This article also referenced another myokine, Interleukin-6 (IL-6), that is released during exercise and helps regulate metabolism and glucose control. IL-6 promotes fat oxidation and the production of beta-hydroxybutyrate (ketones), which can cross the blood-brain barrier and stimulate BDNF. IL-6 improves insulin sensitivity, which improves glucose metabolism in the brain. A side concept that I find interesting and am exploring more is how working out fasted, appears to increase IL-6 while training on carbohydrate intake prior or during exercise may not allow the increase of this myokine which will be a discussion for another writing.
While you don’t need to remember these specific mechanisms, the important concept to remember is that even if you are not seeing the physical body changes from your exercise efforts, the most important changes may not be visible, as in the changes taking place in your brain that will improve your cognitive health as you age. Even if you have the 6-pack of abs, does it really matter if you can’t remember who you are? One of our main goals of exercise is to stimulate the production of BDNF to improve our cognition overtime as we age.
This article concludes by suggesting that while exercise includes physical fitness, it is essential for brain health in enhancing cognition, preventing neurodegeneration, and improving mental well-being throughout life.
Article Referenced
Pedersen, B.K. Physical activity and muscle–brain crosstalk. Nat Rev Endocrinol 15, 383–392 (2019). https://doi.org/10.1038/s41574-019-0174-x
