"The Stress Test"
Did you know that stress can kill you?
Did you know that stress can influence your biology, psychology and behaviour in ways that may damage your health?
Did you know that stress is associated with dying younger?
Did you know that stress is associated with suicide?
Do you want 10 tips to help you cope better with stress?
Alarmingly, many people are unaware that stress is a quiet killer and overtime it can negatively impact on your health and wellbeing. The aim of this brief blog post is raise awareness that stress can be damaging for your health.
Extent of the problem
Stress is everywhere; it impacts everyone and pervades all aspects of our lives. Stress is now one of the most common causes of long-term sick leave and accounts for in excess of 12 million working days lost per annum in the UK (HSE, 2020). In 2019/20, work-related stress, depression and anxiety accounted for 51% of all cases of work-related illnesses in the UK (i.e., 828,000 cases). In the United States, the impact of stress is also far reaching, with 66% of Americans reporting that stress is impacting on their physical health and 63% believing the same for their mental health (American Psychological Association, 2012).
What is stress?
Stress is best viewed as an umbrella term that includes stressors, which are events and issues in your environment that can cause strain. Stressors can be large such as major life events (e.g., death of a loved one, losing your job) or working in a stressful work environment (with high demands and low levels of control), as well as small, such as encountering daily hassles/stressors (e.g., being late for meeting, argument with your partner). Importantly, an individual will only “feel stressed” when they believe they do not have the resources to meet the demands of a particular stressor and remember large and small stressors can impact your health.
How can stress influence your health?
It can do this in two main ways:
Stress can directly impact on basic biological processes that are important for your health (e.g., cardiovascular, endocrine and immune processes). These are known as autonomic and neuroendocrine responses that trigger the release of important hormones such as cortisol and adrenaline that may damage your health if released over long periods of time.
Stress can also indirectly impact on your health by changing or disrupting the habitual health behaviours you engage in every day (i.e., eating a balance diet, exercise, sleeping well). For example, stress has been shown to impact on weight gain by influencing changes in eating behaviour. Many adults and children are prone to eating more unhealthy, high fat snack foods on days when they feel stressed, known as stress-induced eating (see figure below). If these changes are maintained overtime, they're likely to be bad for your health.
What happens when you experience stress – a more technical summary
Two systems are activated (see figure 2.3 below). The first and easiest to activate is the sympathetic adrenal medullary (SAM) system; the second is the hypothalamic–pituitary–adrenal (HPA) axis (O'Connor, Thayer & Vedhara, 2021).
To borrow an analogy from Clow (2001: p. 53) activating the SAM system:
“can be likened to lighting a match whereas activating the HPA axis is like lighting a fire. Lighting a match is easy, has an instant effect and the effect does not last long, whereas lighting a fire takes a lot more effort and its effects last much longer. The HPA axis is only activated in extreme circumstances”.
In the context of stress and eating, we are particularly interested in the HPA axis. When an individual experiences an unpleasant event in their environment that they perceive as stressful, the hypothalamus releases corticotrophin releasing factor (CRF). Once released, CRF is transported in the blood supply to the pituitary gland where it stimulates the release of adrenocorticotrophic hormone (ACTH). Subsequently, the latter hormone travels through the circulatory system to the adrenal cortex where it stimulates production of the glucocorticoid cortisol – known as the ‘stress hormone.’ One of the central functions of cortisol is to increase access to energy stores, increase protein and fat mobilization, and decrease inflammation. Therefore, when an individual experiences stress, the release of cortisol triggers excess energy stored in the muscle and liver as glycogen to be liberated and broken down into glucose ready for utilization by the muscles and brain.
Stress in the 21st Century
It is important to remember that in our evolutionary past, the human stress response existed to deal with acutely stressful encounters such as being attacked by a wildebeest on a prairie. When such stressors occurred, the stress response system switched on to deal with the stressor – the fight or flight response – and then would switch off and our basic biological systems would go back to normal. However, many of the stressors we encounter in modern life are regular, frequent and spill-over from work into leisure time. The stressors we encounter arise from all aspects of our life (home, work, family, relationships etc.) and they can be large and small. As result, many of us are exposed to stressors all of the time which means that our stress response system may remain switched on for longer periods of time. This excessive wear and tear can lead the system to “break” or become dysregulated, which may be damaging for our health. One leading stress researcher calls this “allostatic load” and suggests that the long term impact of stress affects the body at cardiovascular, metabolic, neural, behavioural and cellular levels (McEwen, 1998).
Worrying is bad for your health!
Recent developments in stress research have highlighted the importance of worry, rumination and repetitive thought in improving our understanding of how stress leads to disease. These repetitive thoughts we have about past stressful events or feared future events are known as perseverative cognition (PC). Brosschot et al. (2006), in their perseverative cognition hypothesis, have suggested that worry or repetitive thinking may lead to disease by prolonging stress-related physiological activation by amplifying short-term responses, delaying recovery or reactivating responses after a stressor has been experienced. More recently, Ottaviani et al. (2016) conducted a comprehensive meta-analysis and concluded that there was clear evidence that PC affects cardiovascular, autonomic and endocrine nervous system pathways consistent with a pathogenic route to long-term disease outcomes (see figure below). Specifically, they found higher levels of heart rate, blood pressure and cortisol activity and lower heart rate variability during PC or related to trait PC. In other words, the repetitive thoughts we have in our mind about past stressful events or feared future events may be damaging for our health. Recently, we have also shown (see figure below) that worry and rumination are also associated with increases in health risk behaviours such as substance use, alcohol consumption, unhealthy eating, smoking and sleep (Clancy et al., 2016; 2020). Therefore, be aware that worrying and ruminating about stressful events may be bad for your health! One of our recent reviews has
Stress and suicide
Our recent work has also shown that exposure to stressors (and trauma) over time may cause the stress response system to "break" leading to increased vulnerability to suicide. A number of recent studies have shown that individuals who have previously tried to take their own lives or have thought about ending their lives also release less cortisol when they are stressed (O'Connor et al., 2017; Melhem et al., 2016). As you can see below, our recent study found that individuals who had previously attempted suicide released the lowest cortisol levels in response to a laboratory stressor. Moreover, evidence is emerging suggesting that early life experiences, such as childhood trauma, are associated with "broken" stress responsivity (also known as blunted HPA axis reactivity) and influences daily cortisol levels upon awakening in adulthood in these vulnerable individuals (O'Connor et al., 2018; O'Connor et al.., 2020). These findings are important as they show that stress plays an important role in suicide behaviour. However, future work is required to understand the exact mechanisms that link stress, cortisol, trauma and suicide risk.
The Importance of being Stress Aware
As mentioned at the beginning of this blog, many people do not know that stress can impact on their health by directly influencing vital biological processes or indirectly by modifying the types of health behaviours they regularly engage in. Therefore, it is important to be more stress aware and to take steps to try to lead a more stress-protected life. Below are some easy tips to help you cope better with the stressors and strains of busy, hectic lives.
Ten Tips to Cope Better with Stress
Are you an emotional eater?
Do you tend to eat more when you’re anxious, emotional or stressed? If so, download our Stress Management Support tool and give it a try.
Are you a worrier? If so, here’s a recent blog outlining evidence-based ways to help you worry less
Further links to our work are below