In some way or another, we all feel stress each day, particularly now in the midst of a pandemic and for some of us, lockdown. Stress can be big, it can be small. We can be acutely aware of the stress we are experiencing or it can be subconscious or chronic. When left unchecked, stress can lead to physiological changes and potentially disease.
Stress is the body's response to both internal and external stimuli that the body perceives to be a threat to its balance mechanisms, or homeostasis, in response the body attempts to restore or maintain balance. When we are experiencing chronic stress, the adaptations that our body undergoes to manage the stress can turn pathological leading to further imbalances and potentially disease.
In times of stress, the hormone cortisol is released into the bloodstream along with adrenaline and cholesterol, activating the pituitary and adrenal glands and stimulating the secretion of adrenocorticotropic hormone (ACTH) in response to the stressor. The increased cortisol prompts the ‘fight or flight’ response from the sympathetic nervous system and increases the internal (endogenous) production of blood glucose from the breakdown of stored proteins and fats for energy, while also increasing blood pressure to the limbs to support muscle function and changes the immune response. These changes to the immune system can lead to increased infection risk if the stress is chronic. Increases in blood glucose levels in response to cortisol may promote insulin resistance, change the way we breakdown and metabolise macronutrients, the way bones are formed and impact memory and cognition.
Studies have shown that chronic stress and subsequent high cortisol levels are associated with an increased risk of psychological disorders, insomnia, gastrointestinal disorders, hypertension, cardiovascular disease, metabolic syndrome and an increase in inflammation.
Furthermore, high cortisol levels may increase appetite as the body adapts to increased demand for energy supply in response to the stress. This appetite increase may lead to weight gain with increased weight deposited in the abdominal area, increasing metabolic syndrome and cardiovascular disease risk.
Normal cortisol secretion by the body follows the circadian rhythm, in that it is released in the morning in response to day light to stimulate alertness for the day, with levels decreasing throughout the day and into the evening to allow for sleep (De Sio et al., 2018, p. 9013). An increase in stress and cortisol levels can make falling asleep in the evening hard and may promote insomnia.
Chronic occupational stress, such as police work, is associated with an increased risk of adverse health, therefore, people with high levels of occupational stress may need support with their diet and lifestyle to lower their risk of cardiovascular disease, metabolic syndrome and compromised immune function. Working remotely may contribute to our stress levels as we no longer have the social interaction and support from peers and colleagues to reduce the stress associated with high workloads, making social interaction, exercise and stress reduction even more important in times of remote workplaces.
Interestingly, it is not all bad when it comes to stress. Work related stress and general stress within reason can support alertness and support energy production by the body, it is only when stress exceeds our body's coping mechanisms that it may be detrimental.
So, how do we lower our stress levels? Studies have shown that social interaction and interpersonal touch can reduce cortisol levels and blood pressure associated with stress. Think of the small child looking for comfort or reassurance in the arms of their parents, a wonderful coping mechanism to reduce emotional and physical stress. While communication mediums like FaceTime, Zoom and Skype give us the social and emotional contact with another person, they lack the tactile benefits. Thankfully research has shown that they can still function to reduce cortisol levels without the associated touch of another person. With lockdowns lifting throughout Australia, now is the time to meet up with friends and family, go for a picnic, get back into your exercise routine, or start a new one (I am working on the Couch to 5km running app) and get back into nature to support a reduction in stress.
Cortisol secretion and chronic stress
Stress is a biological response to either internal and external stimuli that threatens the body’s homeostasis (Amabebe & Anumba, 2018, p. 1). In the presence of stress, adaptive and compensatory physiological responses are made by the body in an attempt to restore homeostasis, however with chronic stress, the physiological changes can turn pathological leading to further imbalances (Walvekar et al., 2015, p. 10).
In times of stress, the steroid hormone cortisol is released into the bloodstream along with adrenaline, cholesterol (both LDL-cholesterol and HDL-cholesterol) (Maduka et al., 2015, p. 134). It is suggested by Maduka et al., that the increase in serum cortisol is a result of the hypothalamic neuronal secretion of corticotropin releasing hormone (CRH) and arginine-vasopressin into the hypophyseal portal system leading to the activation of the pituitary and adrenal glands via the HPA system to stimulate the secretion of adrenocorticotropic hormone (ACTH) in response to the stressor (2015, p. 135).
An increase in serum cortisol prompts the ‘fight or flight’ response by upregulating gluconeogenesis, proteolysis and lipolysis to increase blood glucose levels and supporting an increase in the production of ATP, while also increasing blood pressure to the periphery to support muscle function and alters the immune response (Amabebe & Anumba, 2018, p. 1). Ongoing stress can lead to an increased risk of infection (Maduka et al., 2015, p. 135). Increases in glucose production in response to high cortisol levels also induce insulin resistance, alter macronutrient metabolism, sodium transport, bone formation and impact memory and cognition (Amabebe & Anumba, 2018, p. 2).
Studies have shown that chronic stress and associated high cortisol levels are associated with an increase in psychological disorders, insomnia, gastrointestinal disorders, hypertension, cardiovascular disease and metabolic syndrome (Walvekar et al., 2015, p. 10). Hyperactivity of the HPA axis is associated with high cortisol secretion in metabolic syndrome (Walvekar et al., 2015, p. 10). Furthermore, high cortisol levels are associated with an increase in appetite stimulation as an adaptive mechanism to increase energy supplies, with high cortisol levels associated with an increase in weight gain, with a focus on the deposition of weight in the trunk, increasing metabolic syndrome risks (Lawson et al., 2011, p. 6).
Cortisol levels can be tested in urinary, salivary and serum tests which allow for the daily fluctuation based on the circadian rhythm (De Sio et al., 2018, p. 9013). Accurate cortisol levels are best tested by serum test at 8:00am in the morning to account for circadian fluctuation, or through 24 hour urine collection testing (De Sio et al., 2018, p. 9016).
Occupational stress such as police work is associated with increased risk of adverse health, which is important for Nutritionists to understand. Supporting clients with high levels of occupational stress through diet and lifestyle advice can lower their risk of cardiovascular disease, metabolic syndrome and compromised immune function.
Studies have shown that social interaction and interpersonal touch can reduce cortisol levels (Sumioka et al., 2013, p. 1).
Amabebe, E., & Anumba, D. O. C. (2018). Psychosocial stress, cortisol levels, and maintenance of vaginal health. Frontiers in Endocrinology, 9(SEP), 1–11. https://doi.org/10.3389/fendo.2018.00568
De Sio, S. D., Letizia, C., Petramala, L., Saracino, V., Cedrone, F., Sanguigni, P., Buomprisco, G., Perri, R., Battagliola, E. T., Mannocci, A., & La Torre, G. (2018). Work-related stress and cortisol levels: Is there an association? Results of an observational study. European Review for Medical and Pharmacological Sciences, 22(24), 9012–9017. https://doi.org/10.26355/eurrev_201812_16672
Joshua, J. J., & Sherita, H. G. (2017). Cortisol dysregulation: the bidirectional link between stress, depression and type 2 diabetes mellitus. Annals of the New York Academy of Sciences, 1391(1), 20–34. https://doi.org/10.1111/nyas.13217.Cortisol
Lawson, E. A., Eddy, K. T., Donoho, D., Misra, M., Miller, K. K., Meenaghan, E., Lydecker, J., Herzog, D., & Klibanski, A. (2011). Appetite-regulating hormones cortisol and peptide YY are associated with disordered eating psychopathology, independent of body mass index. European Journal of Endocrinology, 164(2), 253–261. https://doi.org/10.1530/EJE-10-0523
Maduka, I. C., Neboh, E. E., & Ufelle, S. A. (2015). The relationship between serum cortisol, adrenaline, blood glucose and lipid profile of undergraduate students under examination stress. African Health Sciences, 15(1), 131–136. https://doi.org/10.4314/ahs.v15i1.18
Sumioka, H., Nakae, A., Kanai, R., & Ishiguro, H. (2013). Huggable communication medium decreases cortisol levels. Scientific Reports, 3, 1–6. https://doi.org/10.1038/srep03034
Walvekar, S. S., Ambekar, J. G., & Devaranavadagi, B. B. (2015). Study on serum cortisol and perceived stress scale in the police constables. Journal of Clinical and Diagnostic Research, 9(2), BC10–BC14. https://doi.org/10.7860/JCDR/2015/12015.5576