All Things Biology

What could you do less of?

When prompted with this question the first thing that pops into my mind is… stress! Being a final year Biological Sciences student with a plethora of deadlines coming up, managing stress is vital to promote productivity and well-being. Just a simple Google search on how to reduce stress generates a multitude of methods, each with a range of scientific backing. So how can you know which ones are scientifically proven to reduce your stress?

What is stress and why is it bad?

Looking at stress from an evolutionary perspective, it is your body’s natural response to negative external or internal pressures. The stress response is a result of internal or external stimuli that disrupt homeostasis (2), triggering the activation of the sympathetic-adreno-medullar (SAM) axis, the hypothalamus-pituitary-adrenal (HPA) axis and the immune system (2). Ultimately the stress response is an incredibly complex system, composed of highly interconnected neuroendocrine, cellular and molecular infrastructure (1).

Activation of the stress response may be brought on by invasive surgery, where the body’s stress response prevents further tissue damage (2), or it can be brought on by emotional stressors like daily pressures from work, school, relationships, family, etc. These, which some might describe as feeling like constant pressures, can cause repetitive (repeat acute stress) or prolonged stress (chronic stress) which ultimately harms an individual’s health by causing maladaptive reactions like anxiety, depression, and heart disease (2), raised blood sugar, a weakened immune system, increased cancer risk, weight gain and more.

So the effects of stress can be detrimental to your health, it’s vital to reduce stress levels to ensure a long, healthy life. Ok now I have stressed you about stress let me suggest some scientifically backed methods which help you can reduce your stress levels!

Stress put simply:

In simple terms, when we feel stressed our adrenocorticotropic hormone levels increase. High levels of adrenocorticotropic hormone trigger the adrenal gland to produce more cortisol (the stress hormone). High cortisol levels can be beneficial as high cortisol levels in acute times of stress trigger mechanisms to promote survival. However, consistently raised cortisol levels have these maladaptive effects mentioned before. So if you could lower your cortisol levels, you can also lower your stress.

Your cortisol levels are usually higher in the morning than the evening as cortisol follows a CIRCADIAN rhythm (3)

Fun Fact

How to lower cortisol levels:

Exercising:

Exercising is one any doctor will advise you to embark on as a way of reducing stress. But, did you know that exercise actually increases cortisol levels? A study conducted by Chen and colleagues in 2017 looked at cortisol release from the stress response and from exercise. They found that while both resulted in raised cortisol levels, raised levels of glucocorticoid cortisol due to activation of the hypothalamic-pituitary-adrenal axis from exercise also promoted dopamine production in the medial prefrontal cortex (4) (explaining runners high) and had an overall beneficial influence on the body compared to the effect of raised cortisol levels due to stress (4).

This may be because dopamine plays a role in the body’s coping mechanism to stress (5) due to the dopaminergic reward system (which monitors and selects the next step in coping with stressful situations (6) following an initial rise in cortisol levels).

Prolonged stress can result in lower sensitivity of the dopaminergic reward system (meaning it needs higher levels of cortisol to be triggered), which can result in stress-induced depression (6). Increases in medial prefrontal dopamine due to exercise enables active coping to stress response (4). Put simply, increased exercise increases the ability of the body to cope with stress.

Increased exercise has also been shown to protect against the negative emotional consequences of stress by increasing resilience to stress (8) as well as improving sleep quality (7).

Sleep:

Is your stress making it challenging to sleep? High cortisol levels can result in fragmented sleep and insomnia but did you know that your interrupted sleep is further increasing your cortisol levels, it’s an endless cycle… A study found that sleeping 5.5 hours or less a night resulted in increased cortisol levels (9) highlighting the importance of getting a full night’s sleep. But how can you go about improving your sleep quality other than through exercise?

High cortisol levels in the morning stimulate you to wake up. These levels stay raised throughout the day which helps keep us awake but at night we need these levels to decrease so other hormones like adenosine and melatonin can increase and make us feel tired (13). When we are stressed we have abnormally high cortisol levels, therefore it is important to use proven methods such as deep breathing (11), positive compassion and yoga (12) to reduce cortisol levels (11) before bed, giving our bodies a chance to rest.

Stay away from drugs!

I’m talking about nicotine (14), caffeine (16) and alcohol (15), all of which increase your cortisol levels… ironic since these are what most people go to when they feel stressed!

To conclude…

Ultimately, cortisol is a vital hormone which plays a role in multiple important systems within the body however, long-term increased levels of cortisol can have detrimental impacts on your health. Therefore, understanding the biology behind cortisol and how to reduce its levels when stressed will improve your overall health and well-being.

Written by Francesca Giannachi-Kaye

Reference list:

1. https://www.ncbi.nlm.nih.gov/books/NBK278995/
2. https://www.ncbi.nlm.nih.gov/books/NBK541120/
3. https://www.medicalnewstoday.com/articles/cortisol-and-stress#faq
4. https://pubmed.ncbi.nlm.nih.gov/27956050/
5. https://www.sciencedirect.com/science/article/abs/pii/B9780128131466000096
6. https://www.nature.com/articles/s12276-020-00532-4#Sec2
7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5385214/
8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4013452/
9. https://www.sciencedirect.com/science/article/pii/S2451965021000363
10. https://www.healthline.com/nutrition/ways-to-lower-cortisol#TOC_TITLE_HDR_6
11. https://pubmed.ncbi.nlm.nih.gov/28626434/
12. https://pubmed.ncbi.nlm.nih.gov/25559560/
13. https://www.psychologytoday.com/us/blog/sleep-newzzz/202004/the-effects-cortisol-your-sleep
14. https://pubmed.ncbi.nlm.nih.gov/16337291/
15. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8329388/
16. https://pubmed.ncbi.nlm.nih.gov/16204431/