I’m interested in all things mental health and what we can do to take care of our mental health. We know that exercise is one of the most effective tools for battling depression, whether its something you do to shake up your acute depression or whether it’s looking at the literature.
For example, the British Journal of Sports Medicine just published in February, 2023, a meta-analysis, 41 studies with over 2,264 participants that looked at how exercise affects major depressive disorder. They found a very large effect size. In fact, they found a number needed to treat of two, which means when we meet someone with depression, we only have to talk to two people about exercise or prescribe exercise to get one person into full remission.That’s a very powerful number when it comes to medicine and research and how we take care of individuals with depression.
So how does this happen? Let’s get to that word. Myokines. Why are myokines so interesting and what are they? Myokines are the molecules that your muscles make when you exercise. Scientists have discovered very recently there are over 650 different molecules that get made by muscles when they’re active and only 5% of the function of those molecules are known. What we know so far is really impressive though. Myokines travel throughout the body and they have both endocrine and paracrine effects, meaning they interact with and influence organs and cells far away from where they’re created and also in that surrounding area of where they’re created. So they exhibit a tremendously powerful function in how they affect our body and most importantly, for us thinking about mental health, how they affect our brain and our mind.
So how do myokines do this? Well, there’s a number of ways. First of all, like most molecules, many myokines cannot pass the blood-brain barrier. So instead, they bind to cell receptors on the blood-brain barrier and influence the brain that way. A few of the myokines, however, can cross the blood brain barrier. Molecules, for example, like BDNF or interleukin 6, can cross the blood brain barrier and have a variety of effects on the brain. Most famously, exercise is known for inducing neuroplasticity via BDNF. This is a fancy way of saying that exercise helps the brain grow, repair, and connect and this is an important function. You can see this in the research studies fairly quickly. For example, if you take individuals with some cognitive deficits or who are struggling with depression, which often comes with cognitive deficits and you put them in a structured exercise program, you begin to see tremendous improvement in both their cognition and their mood.
I hope this idea of myokines can stick with you. I know it’s helped me as I’ve thought about getting more motivated and exercising more, especially as I’m aging. I think about all of these muscles in my body as little factories creating all these wonderful molecules, helping my mental health and helping my mind in all kinds of ways that science is discovering. I hope this helps you get out there, stay active, have fun, and while you’re doing so, keep in mind that you’re producing all kinds of wonderful molecules in your muscles that influence your mental health and your brain growth.