Stress, health and brain function
By Trish Darcy, Jan 1 2017 02:00AM
Chronic stress has been shown to have negative outcomes on health with increased risks for the development of chronic health conditions such as CVD, auto-immune disease, diabetes, and cancer (Cohen et al., 2007).
Our modern fast-paced lifestyles have resulted in an increased exposure to a myriad of stressors including environmental stress (noise and air pollution, technology), lifestyle stress (longer working hours, highly processed foods, sedentary lifestyles), and personal stress (job insecurity, financial debt). In addition, more than half the world’s population and over 70% of Europe’s population now reside in an urban environment (Dye, 2008), with social stress and mental ill-health increasingly associated with urban living (Lederbogen et al., 2011, Peen et al., 2010). This impact of acute and chronic stress can result in depletion and the development of chronic health conditions over time.
The HPA axis plays a central role in maintaining homeostasis in the body, of which the hypothalamus is the main control centre and is directly influenced by stress. Cortisol is the main hormone produced by adrenal cortex in response to stress, and which negatively inhibits both the Hypothalmus and the Pituitary gland in the brain. The HPA axis has been shown to respond differently during chronic stress according to the type of stressor and make-up of the person (Kudielka et al., 2009). Stressors that are experienced as uncontrollable, traumatic, or threaten physical integrity typically result in an abnormal stress response as indicated by cortisol.
Stress interventions, such as exercise and meditation, play a pivotal role in stress management as they modify the biological response of cortisol which in turn can prevent the deterioration of health or the development of other health conditions.