Stress is an inevitable part of life. Pleasant or unpleasant, it is a shared part of the human experience. On the plus side, stress can frequently serve as a powerful, motivating force. Without it, we might struggle to get things done or stay on track. However, more often, stress feels like an overwhelming by-product of modern living.
With the abundance of everyday stressors we face, it is easy to see how we can be pushed into a state of sensory overload if stress is left unchecked. In the age of the smart phone and social media, we are putting more and more pressure on ourselves to meet increasingly higher standards set by carefully curated Facebook profiles. We are under pressure to be constantly available and “switched on.” Couple these stressors with the stress of major life events, such as a death in the family, and many of us will also experience periods of profound stress that begin to affect both our mental and physical health.
I decided to write a series of articles focussing on the physiological effects of chronic stress and explore how we can work to become more resilient. In this first article, we will look at what is happening in the body when we are continually stressed out and touch briefly on methods of stress management. I will be exploring some of these in further detail in my upcoming blogs.
Our modern stressors are vast.
In evolutionary terms, we experience stress to protect our survival. Stress is a process of reacting to threats in our environment in order to maintain homeostasis (balance) in the body. Essentially, we experience stress to keep ourselves safe.
However, our brains have not evolved at the same rate as our modern lifestyles. This is where the problem lies. Our stress reaction may have been quite useful to our ancient predecessors who might worry about being eating by a large mountain lion. However, our brains have not evolved to decipher the difference between the stress of the real, physical danger of our hunter-gather days or repeated unpleasant thoughts. Both will trigger that all too familiar “fight or flight” instinct along with a myriad of hormonal changes in the body which mobilise us for physical action. Yet, we are, for the most part, no longer on the run from a hungry mountain lion. These days, the source of modern stress is more often related to our psychosocial conditions. Still, our body responds in exactly the same way. This puts us at risk for a range of health problems.
Some examples of modern stressors:
- A fast-paced lifestyle
- Long working hours
- Distorted thinking habits
- Toxic relationships
- Life changes (e.g. divorce, losing a job, moving house, getting married)
- Financial concerns
- Poor health
The function of cortisol in stress.
In the short term, our brains activate the sympathetic nervous system to release the hormone adrenaline (epinephrine) triggering your “fight or flight” reaction. Once this flow of adrenaline dies down, there is a secondary component of our stress reaction, which occurs via the hypothalamic-pituitary-adrenal (HPA) axis. Put simply, when the hypothalamus (in the brain) senses a stressor, it triggers the release of a cascade of different hormones ending with the secretion of cortisol from the adrenal glands (just above each kidney). The role of cortisol in stress is to shift energy away from unnecessary cellular processes and toward those, which support immediate survival. Cortisol is the master hormone of our sustained stress response.
During stress, cortisol works to:
- Increase blood glucose levels. Cortisol is a “catabolic” hormone, which means it helps to break down the body’s energy stores (e.g. fat and muscle) into glucose. This is to have a readily available pool of glucose to supply to our muscles to fuel “flight or flight.”
- Increase blood pressure. Cortisol helps to narrow the arteries, in order to more rapidly supply blood to our muscle tissues, preparing them for action.
- Dampen down inflammatory and immune responses. These are considered non-essential during the stress response.
- Inhibit other non-essential functions – including growth and reproduction.
Theoretically, once the stressor goes away, the body relaxes and cortisol production decreases. However, during a prolonged stress response (due to repeated periods of stress), this process becomes maladaptive, which can lead to chronically high blood levels of cortisol.
What are the effects of chronic stress and long-term cortisol production?
There are a variety of ways that chronic stress and long-term cortisol production can affect your health. If you are experiencing any the issues below, I would advise you to further discuss them with your GP.
- Reduced immune activity and decreased resistance to infection
- Insulin resistance or exacerbation of existing diabetes
- Increased risk of heart disease
- High blood pressure
- Anxiety, depression or burnout
- Weight gain
- Impaired digestion and gastrointestinal problems
- Insomnia and sleep disorders
- Fertility issues
- Low libido
- Reduced bone mineral density
- Decreased memory or forgetfulness
Although stress is an inevitable product of modern life, there are some things you can do about it. This list is not exhaustive, but may help to get you started.
- Moderate Exercise
- Reduce caffeine intake
- Limit alcohol consumption
- Mindfulness meditation
- Practice self-compassion (see our article on perfectionism)
- Keep to a realistic schedule (e.g. set fewer expectations, prioritize, delegate)
- Aim for 7-8 hours per night of good quality sleep (see our article on sleep hygiene)
- Professional support (e.g. counselling or cognitive behavioural therapy)
- Maintain a healthy diet (low in processed foods; high in whole fruit and vegetables, whole grains, moderate amounts of lean meat and fish, beans and pulses and low fat/no added sugar dairy products).
In the next part of this series, I will explore how chronic stress and the hormone cortisol can lead to changes in body composition, specifically an increase in abdominal fat. We will also look at changes you can make to the diet to support your health during stressful periods.
What are your experiences with chronic stress? Feel free to extend the discussion in the comments section below.
Aronson, D. (2009). Cortisol – Its Role in Stress, Inflammation, and Indications for Diet Therapy. Today’s Dietitian. 11(11): 38.
Bergland, C. (2014). Psychology Today: Chronic stress can damage brain structure and connectivity. Available online: https://www.psychologytoday.com/blog/the-athletes-way/201402/chronic-stress-can-damage-brain-structure-and-connectivity
Chrousos, G.P. (2009). Stress and disorders of the stress system. Nat Rev Endocrinol. 5(7):374-8
Smith, S.M. and Vale, W.W. (2006). The role of the hypothalamic-pituitary-adrenal axis in neuroendocrine responses to stress. Dialogues Clin Neurosci. 8(4): 383–395.
Shwartz, M. (2007). Stanford Report: Robert Sapolsky discusses physiological effects of stress. Available online: http://news.stanford.edu/news/2007/march7/sapolskysr-030707.html.
Widmaier, E.P. et al. (2008). Vander’s Human Physiology: The Mechanisms of Body Function. 11th Edition. New York: McGraw Hill.