Jess Barber (B. Nutrition and dietetics) shares an important ⁣⁣message on the way stress interacts with the human body and how you can combat it 

Individuals in the health and wellness space will jump at the opportunity to try a new diet if they think it will help their health issues. However, when a health professional recommends stress reduction techniques, it generally gets an eye roll. Through the exploration of the gut-brain connection, there is a significant body of evidence supporting the implementation of stress reduction techniques for numerous health issues… I think it has become a common thought that stress is purely an emotional and psychological condition, however, it has true and damaging physiological and physical manifestations in our body.


I think it’s time we start thinking of stress reduction as a highly effective treatment option.

So hopefully I’ve now motivated you to keep reading…


What is stress?

A simple google search tells us stress is,a state of mental or emotional strain or tension resulting from adverse or demanding circumstances”. When you’re stressed – emotionally or psychologically, the sympathetic nervous system is involuntarily aroused, and the body enters our ‘fight or flight’ response. This response begins in the brain, with the hypothalamus, telling our adrenal glands to release stress hormones, adrenaline, and cortisol.


What is the role of cortisol and adrenaline?

Overall these hormones:

  • increase your heart rate and breathing
  • constrict the blood vessels
  • relax the bladder
  • inhibit metabolic digestion
  • dilate pupils
  • tighten muscles.

Cortisol causes the body to instinctively shut down into protective mode and shuts down all of the nonessential systems, such as our immune response and digestion. Which, when you think about it, makes sense. If we are running away from a tiger, you don’t want to be devoting energy to fighting off a virus or digesting your breakfast. It prioritises all of the bodily systems needed to respond to the emergency, such as your muscles and heart.


Why is stress problematic for our health?

When the stressor is removed, the hypothalamus will stop sending signals and all systems should return back to normal (homeostasis). The stress response becomes an issue when you are experiencing prolonged stress and negative physiological effects occur. The ways in which stress effects the different systems and processes in our body is outlined below.




Stress and Inflammation

Research is constantly being conducted to understand how stress impacts inflammation in the body (Cohen., et al. 2012). Cohen et al. (2012) found that chronic psychological stress is associated with the body losing its ability to regulate the inflammatory response.


As mentioned, when we are stressed, cortisol is high. Among its many roles, cortisol also plays a role in regulating inflammation.


“Inflammation is partly regulated by the hormone cortisol and when cortisol is not allowed to serve this function, inflammation can get out of control,” said Cohen, the Robert E. Doherty Professor of Psychology from CMU’s Dietrich College of Humanities and Social Sciences.


So, when stress is prolonged, it alters the effectiveness of cortisol in regulating the inflammatory response. HOW? Our immune cells become insensitive to cortisol’s regulatory effect and as a result inflammation occurs.


Cohen added, “When under stress, cells of the immune system are unable to respond to hormonal control, and consequently, produce levels of inflammation that promote disease. Because inflammation plays a role in many diseases such as cardiovascular, asthma and autoimmune disorders, this model suggests why stress impacts them as well.”


Stress and the immune system?

Dorshkind & Horseman (2001) showed that stress has an immunosuppressive effect – that is, immune system is down regulated when an individual is stressed. Again, cortisol plays a role. Cortisol does not usually cause harm to the immune system, however, when experiencing chronic stress, cortisol is present in the blood for a prolonged period of time and has been thought to interfere with the production of the antibodies (the good guys which target foreign particles). Additionally, cortisol can decrease the number of lymphocytes (our protective white blood cells) putting you at risk of viruses like the common cold.


Also, when we are stressed, we are more likely to have unhealthy coping mechanisms such as drinking, smoking, or eating unhealthily, which can have an indirect effect on our immune system.


Stress and the Gut


Gut symptoms

To understand the effect of stress on the gut we must first understand that the gut and brain are intrinsically linked. There is a bidirectional network which connects the brain and gut. Because of this network, signals from the brain can affect the functions of the gastrointestinal tract and visceral messages from the gut can impact the brain (Allen, Dinan, Clarke, & Cryan, 2017).


When the brain recognises an external source of stress and the sympathetic nervous system is activated energy is borrowed from the gut. The digestive tract is of low priority when in ‘Fight or flight’ mode and so blood flow to the gut is reduced. Other changes to gastrointestinal function include:

  • reduced mucus production;
  • reduced movement of food through the digestive tract; and
  • heightened gastrointestinal sensitivity.

These changes can trigger gastrointestinal symptoms, including abdominal pain, bloating and changes in stool consistency.


Gut bacteria

Not only can stress affect the digestive tract as a whole, it can also affect the trillions of microbes within the gut, specifically the large intestine. These microbes work together to keep your body thriving.


Interestingly, Allen, et al., (2017) showed that long term chronic stress can reduce the variety of bacterial species in our gut. Variety within the gut microbiome is KEY to our health. Greater variety equals greater health outcomes.


Clinical studies have shown that stress can also reduce the number of good bacteria that help signal the correct response to the brain to cope with and protect you from the physiological effects of… you guessed it, stress. Fortunately for us, stress is manageable, and with healthful decisions, the microbiome can be altered for the better giving us the chance to live, look, act and feel our best (Allen, et al., 2017).


Stress and the cardiovascular system?

Our stress hormones cause our blood vessels to constrict and divert more oxygen to our muscles and essential organs. When our blood vessels become narrower, our blood pressure increases. This puts great strain on our heart, forcing it to pump harder and faster, putting us at risk of greater cardiovascular consequences such as a heart attack (Dimsdale, 2008).


Stress and the skeletal system?

Ever notice your neck and shoulders become super tight or you get a migraine when you’re going through a stressful period? That’s because when we are under stress our muscles become tense in an attempt to protect ourselves from injury. If you are under constant stress, your muscles are constantly tight which can be the cause behind your headaches/migraines, and bodily aches and pain.


What can you do?

Personally, the first question I ask myself is; ‘why am I stressed’. Then I ask, ‘can I change it’? If I can, I start mentally or physically writing the actions I can take to reduce this stress. However, sometimes we can’t change things and may have to temporarily deal with a source of stress. When this is the case, and my mind is super busy, there are a few coping mechanisms I adopt. I do not have a set routine I run through when I feel stressed; Instead, I find having multiple little practices best equips me to deal with different sources of stress.

So… a few things I turn to:

  1. Yoga or a walk
  2. Calling family or a friend to talk/vent
  3. Writing (word vomiting) all of my thoughts down
  4. Not going on social media
  5. Switching off from all work and doing something I love


Other stress reduction techniques that may suit you

  1. Breathwork
  2. Exercise
  3. Muscular relaxation
  4. Meditation
  5. A hobby
  6. Biofeedback
  7. Cognitive-behavioral therapy


I also like to remind myself to let go, to not overthink things, to not attach to my thoughts, to not take things to seriously and when in doubt, just breathe…


“The most evidence-based stress management technique is the natural act of abdominal breathing”.






Cohen, S., Janicki-Deverts, D., Doyle, W. J., Miller, G. E., Frank, E., Rabin, B. S., & Turner, R. B. (2012). Chronic stress, glucocorticoid receptor resistance, inflammation, and disease risk. Proceedings of the National Academy of Sciences of the United States of America, 109(16), 5995-5999. doi:10.1073/pnas.1118355109


Dorshkind, K., & Horseman, N. D. (2001). Anterior pituitary hormones, stress, and immune system homeostasis. Bioessays, 23(3), 288-294. doi:10.1002/1521-1878(200103)23:3<288::AID-BIES1039>3.0.CO;2-P


Allen, A. P., Dinan, T. G., Clarke, G., & Cryan, J. F. (2017). A psychology of the human brain–gut–microbiome axis. Social and Personality Psychology Compass, 11(4), e12309-n/a. doi:10.1111/spc3.12309


Dimsdale, J. (2008). Psychological Stress and Cardiovascular Disease. Journal Of The American College Of Cardiology, 51(13), 1237-1246. doi: 10.1016/j.jacc.2007.12.024