Many of us know that cortisol is linked to stress - it’s the stress hormone! - but few people understand the other roles that cortisol plays in the body and how it works to keep us alive.
Read on to find out more.
The role of cortisol in the body
When we talk about stress, we often think about rising cortisol levels. But cortisol also does much more in the body than simply triggering a stress response.
Cortisol is one of the many hormones responsible for helping us adapt to our environment. This doesn’t always have to be “stressful” events. Cortisol levels can go up and down within minutes as we respond to different stimuli around us.
There’s also a rhythm to the release of cortisol through the day. High levels of cortisol flood through the body in the early morning to help wake us up. Our cortisol levels then typically reduce during the day and are normally low in the evening and at night. Cortisol release is part of our circadian rhythm.
As well as playing a part in the body’s stress response, cortisol also helps us to learn and adapt. The day-to-night rhythm of cortisol release promotes the formation and destruction of certain synapses in the brain. Cortisol is also involved in helping the immune system respond to pathogens in the body and speed up wound healing.
Rethinking cortisol and stress
The nervous system, the immune system and many regions of the brain respond to changes in the environment that allow us to adapt and maintain balance. However, when this network within the body becomes unbalanced, there is a gradual change throughout the body. Long term stress can lead to disease and have serious consequences.
When the cortisol circadian rhythm is disrupted, for instance in the case of sleep deprivation or depression, the body doesn’t have the same natural fluctuations in cortisol levels. Instead, cortisol levels flatten and stay the same. Consistently high levels of cortisol in the body are associated with obesity, especially in the abdomen, insulin resistance, hypertension and high cholesterol.
One well-researched example of this is shift work. Shift work, aka work outside of the normal 9-5, has been linked to increased incidences of obesity due to disruptions in the natural circadian rhythm of cortisol levels in the blood. Shift work causes hyperactivity in the part of the brain responsible for cortisol secretion, leading to long-term high levels of cortisol in the body and health troubles as a result.
Looking to keep your cortisol levels low?
While cortisol has a big role to play in how the body responds to stress, it is not always the bad guy! Cortisol can help us to adapt to our environment, fight infection and even wake up in the morning.
The problems with cortisol occur when cortisol levels rise and stay high. That’s why it’s important to minimise lifestyle factors that can disrupt the circadian rhythm of cortisol release. This includes keeping a regular sleep schedule, having a good morning routine and taking steps to de-stress.
Cortisol only becomes a problem when the natural rhythm is disrupted, for instance during periods of intense stress. If you can maintain a healthy lifestyle and reduce stress as much as possible, there’s no reason for cortisol not to be your friend!