If you’ve got your finger on the pulse of health trends, it’s likely you’ve been hearing the current buzzwords “cortisol creates belly fat” and “cortisol causes muscle wasting and fat storage.” These are the type of catch phrases that gain momentum every few years. And although some of the fads and trends showing up seasonally in fitness are myths, this caution about chronically elevated cortisol is true. Cortisol is also deeply connected with the dangers of chronic inflammation, which I described in another article, “Inflammation Creates Diseases.” (integre8twellness.com/inflammation-creates-diseases)
Like many hormones, cortisol has an effect on a wide variety of functions in the body. Although it’s getting particularly demonized lately, cortisol serves some very important and positive functions in the body. It’s an essential component of the flight or flight response, so it gives us energy, focus, strength, motivation and courage. But, like with sugar or caffeine, it comes with a crash that feels like an emotional, psychological and physical drain. Cortisol is important for survival, but we didn’t evolve to have high levels of it all the time.
According to hormone.org, cortisol isn’t only a stress hormone: “Because most bodily cells have cortisol receptors, it affects many different functions in the body. Cortisol can help control blood sugar levels, regulate metabolism, help reduce inflammation and assist with memory formulation. It has a controlling effect on salt and water balance and helps control blood pressure. In women, cortisol also supports the developing fetus during pregnancy. All of these functions make cortisol a crucial hormone to protect overall health and well-being.” (hormone.org/hormones-and-health/hormones/cortisol)
There are many symptoms of chronically elevated cortisol levels. With that said, the way a spike of cortisol gives you a jolt of energy is by raising blood sugar. It does this by way of gluconeogenesis. This literally means “creating new sugar,” and it happens by way of breaking protein down into amino acids that are then turned into sugar by the liver. What is a large source of protein in the body? Yep, muscles. This is what is meant by “cortisol causes muscle loss.” This in turn contributes to muscle weakness. Whereas normal levels of cortisol help to regulate blood sugar levels by breaking down only a little muscle (which can be replaced with exercise), excessive levels cause muscle wasting.
Why does cortisol cause fat gain? Remember those cortisol receptors most cells have? Fat cells have four times as many, so they are particularly responsive to cortisol. Okay, remember all that glucose the cortisol surge dumped into your blood for energy? Well, that also came with an insulin response to get your blood sugar levels back down, and insulin causes energy storage. And where do you store the energy? Yep, in those hypersensitive fat cells that cortisol just turned on. And what happens when you have too much insulin over time? Yep, diabetes. Also, another reason stress can cause emotional and/or binge eating is because cortisol also fires up your sense of purpose, as well as your appetite. So now stress has made you feel motivated…to eat.
Emotionally and psychologically, chronically high cortisol can exacerbate depression, anxiety, irritability and lack of emotional control. Cortisol triggers a release of tryptophan oxygenase. This enzyme breaks down tryptophan. Tryptophan is required for creating serotonin. Serotonin gives us the ability to feel happiness, and it also affects appetite, sleep and sexual desire. Since extended exposure to high levels of cortisol inhibits the production of serotonin, all the symptoms of low serotonin become problematic (decreased appetite, insomnia, impotence, etc.). In short, prolonged stress causes depression.
Cortisol also plays a role in the circulatory system. It manipulates blood pressure by acting as a diuretic. Excess cortisol causes an electrolyte imbalance, whereby sodium is retained, but potassium is excreted. Let me take you back to your high school biology days: Muscles fire because of the sodium potassium pump. The sodium potassium pump also effects the firing of nerves, including those impulses that cause your heart to beat and your kidneys to take in water for filtration. That sodium potassium pump is important throughout the entire body, across many of its biological functions. Because cortisol increases the concentration of sodium in your body, it has a direct impact on your blood pressure. Remember why excess salt can cause high blood pressure? Because it contains sodium. For all these reasons and more, chronically elevated cortisol also causes muscle weakness (ironic, since short bursts of it temporarily increase strength).
Cortisol has other effects on minerals. According to the Hindawi Journal of Sports Medicine, “Cortisol triggers bone mineral resorption (removal) in order to free amino acids for use as an energy source through gluconeogenesis. Cortisol indirectly acts on bone by blocking calcium absorption, which decreases bone cell growth.” As you can see, excess cortisol causes osteoporosis. It also exacerbates other bone mineral density diseases, which means cortisol can leave you literally brittle with stress.
Practically anything can become a stressor in the right conditions, and fight or flight is our only biological response to stress. Some triggers of stress include conflict, worry, alcohol and drug consumption, processed foods, excess exercise (especially prolonged and repeated sessions of low-level steady-state cardio training), sleep deprivation, thirst and hunger. As much as possible, protect yourself from stress with rest, relaxation, meditation, play time and healthy foods full of antioxidants, which reduce inflammation and thus the risks for practically all diseases.
Jack Kirven completed the MFA in Dance at UCLA, and earned certification as a personal trainer through NASM. His wellness philosophy is founded upon integrated lifestyles as opposed to isolated workouts. Visit him at jackkirven.com and INTEGRE8Twellness.com.