Top Line
Stressors are inevitable -- nevertheless, we still can counter the negative health implications of stress by choosing how we perceive it, using mind-based strategies like meditation to reduce it, and maintaining an active and exercise-rich lifestyle to bolster the immune system.
Why It Matters
While short term stress does not seem to negatively affect immune system function, exposure to stressors over time -- physical or psychological -- may increase your risk of death by more than threefold. (1)
Key Takeaways
- The nervous system affects the immune system. (13)
- Long-term stress is a major risk factor for the development of disease. (9)
- Meditation, standard relaxation training, progressive muscle relaxation, and exercise can reduce stress and anxiety -- thereby boosting immune function. (2, 3, 11)
There has never been a better time to utilize mind-based (e.g. mediation) and physical-based (e.g. exercise) therapies to combat stress, with COVID-19 undoubtedly one of the largest scale perceived physical and psychological threats in recent history. This event has caused countless Americans concern not only about their health or that of their loved ones, but also about their livelihoods and futures as caused by astronomical spikes in unemployment and a precarious economy. The immunological effects of 2020’s quarantine, political turmoil, and uncertainty are yet to be characterized, however, what is well-documented is that long term exposure to stressors can have severe consequences to your health and wellbeing.
The Brain & Body
The mind, or from an anatomical perspective, the brain, acts as the body’s central hardware and together with the spinal cord makes up the Central Nervous System (CNS). The mind is responsible for consciousness, emotions, memories, reasoning and cognition, and behavior.
The body is a broad reference to the remaining anatomical structures and physiological processes in the human organism.
The brain and body are in constant two-way communication. Perhaps the most relatable example of this bi-directional communication is between the brain and the heart. The heart possesses its own pacemaker, however rhythms (heart rate and force of contraction) may also be controlled outside of the heart by the autonomic nervous system, the body’s “cruise control”.
Sympathetic activity or ‘fight or flight’ mode of the nervous system is responsible for increasing heart rate by controlling the force of contraction, ultimately mediating stroke volume and blood pressure, and involves the norepinephrine neurotransmitter. It takes little more than a loud unexpected sound or an upsetting email for the nervous system to “override” the heart’s internal controls.
The opposite of sympathetic activity is parasympathetic activity, also known simply as the ‘rest and digest’ mode of the nervous system. It is generally responsible for slowing your heart rate and lowering blood pressure.
What is “Stress?”
Stress is defined as an acute threat to an individual’s homeostasis (state of equilibrium) by real or perceived events -- which immediately triggers sympathetic activity in our nervous system (“fight or flight”).
Stressors are considered to be physiological or psychological threat events. (8)
Stressors encompass a wide range of sources, from something as innocuous as a tough workout, to a difficult situation at work, or to an imminent attack by a wild animal.
Regardless of the source, the nervous system response is the same. This means that being fired can be interpreted just as severely as staring at the teeth of a snarling wolf just a few yards away.
How our nervous system responds to stress, should be familiar. In the words of Eminem, reflecting on performance anxiety, “his palms are sweaty, knees weak, arms are heavy” (“Lose Yourself”).
These physical reactions to stress are generated by brain circuits that associate a stimulus with an emotional value (i.e fear, sadness, anger, etc.), which ultimately results in a cascade of sympathetic activations. (8)
How Does Stress Affect Immune Function?
When the nervous system is sympathetically activated, it can affect the immune system in two ways:
- Electrical. It disrupts the “normal” autonomic nervous system function (“cruise control”), which then interferes with immune system functions that occur during “normal” operation.
- Chemical. It causes the endocrine system to initiate hormonal consequences which in turn adversely affect the immune system. (13)
A growing body of research now suggests that chronic stress is a major risk factor for the development of a number of diseases, including cardiovascular disease, cancer, arthritis, and major depression. (9)
A longitudinal study by Aldwin et al., (2014) of stressful life events and everyday hassles, such as long lines at the local store or being stuck in heavy traffic, collected data from 1,293 men between 1989 and 2005, and then followed the men until 2010. The study found about 43% of the men had died by the end of the study period. Around a third of the men who reported having few stressful life events had died, while closer to half of the men reporting moderate or high numbers of stressful events had died by the end of the study. The authors concluded that participants with consistently high hassles/stressors had over three times greater mortality risk. These findings stress the importance of the age-old expression ‘don’t sweat the small stuff’.
Managing Stress: Strategies, Treatments & Prevention's
Stressful life events with the magnitude of the COVID-19 global pandemic or the civil unrest and political turmoil that ensued, are near impossible to avoid, but individuals may live longer if they're able to control their attitudes and maintain a positive mindset.
Positive well-being, defined as the presence of favorable emotional or cognitive psychological attributes such as optimism, has been associated with improved immune function, increased cardiovascular health and lower levels of inflammation. (10)
Mind-based therapies such as meditation, standard relaxation training, and progressive muscle relaxation have been found to reduce stress levels and anxiety. (3,12)
Given the bi-directional relationship of the mind and body, it comes as no surprise that in addition to mind-based therapies exercise has a profound mitigatory effect on stress.
Research indicates that being physically active improves the way your body can cope with stress. (7) Moderate to vigorous intensity exercise elicits changes to hormones and neurotransmitters e.g. dopamine release. (4,6) This chemical buffering mechanism can have a profound effect on mood and behaviors.
If the origin of stress is work-related, breaking the exercise into multiple shorter duration sessions e.g. before work and on lunch break can help mitigate stress throughout the day. (7)
The physiological benefits of regular exercise is recognized across a variety of settings. A study by Battaglia et al., (2015) found that a 9‐month selected physical exercise program enhanced psychological well‐being in a prison population. (2) Sixty‐four participants were randomly assigned across three groups: aerobic and strength training, high‐intensity strength training, and a control of no exercise. Participants assigned to exercise groups had significantly reduced depression scale scores compared with those in the control group. These findings are consistent with previous studies that have shown exercise to have antidepressant and anxiolytic effects, which protect against the harmful consequences of stress. (11)
Stressors are inevitable, especially now. Nevertheless, we still can counter negative health implications by choosing how we perceive stress, using mind-based strategies like meditation to reduce it, and maintaining an active and exercise-rich lifestyle.
George Crouch, MSc
References
- Aldwin, C. M., Jeong, Y. J., Igarashi, H., Choun, S., & Spiro III, A. (2014). Do hassles mediate between life events and mortality in older men?: Longitudinal findings from the VA Normative Aging Study. Experimental Gerontology, 59, 74-80.
- Battaglia, C., di Cagno, A., Fiorilli, G., Giombini, A., Borrione, P., Baralla, F., ... & Pigozzi, F. (2015). Participation in a 9‐month selected physical exercise programme enhances psychological well‐being in a prison population. Criminal Behaviour and Mental Health, 25(5), 343-354.
- Chiesa, A., & Serretti, A. (2009). Mindfulness-based stress reduction for stress management in healthy people: a review and meta-analysis. The Journal of Alternative and Complementary Medicine, 15(5), 593-600.
- Esch, T., & Stefano, G. B. (2010). Endogenous reward mechanisms and their importance in stress reduction, exercise and the brain. Archives of medical science: AMS, 6(3), 447.
- Ginty, A. T., Kraynak, T. E., Fisher, J. P., & Gianaros, P. J. (2017). Cardiovascular and autonomic reactivity to psychological stress: neurophysiological substrates and links to cardiovascular disease. Autonomic Neuroscience, 207, 2-9.
- Greenwood, B. N., & Fleshner, M. (2011). Exercise, stress resistance, and central serotonergic systems. Exercise and sport sciences reviews, 39(3), 140.
- Jackson, E. M. (2013). Stress relief: The role of exercise in stress management. ACSM's Health & Fitness Journal, 17(3), 14-19.
- Motzer, S. A., & Hertig, V. (2004). Stress, stress response, and health. The Nursing Clinics of North America, 39(1), 1-17.
- Muscatell, K. A., & Eisenberger, N. I. (2012). A social neuroscience perspective on stress and health. Social and Personality Psychology Compass, 6(12), 890-904.
- Rausch, S. M., Gramling, S. E., & Auerbach, S. M. (2006). Effects of a single session of large-group meditation and progressive muscle relaxation training on stress reduction, reactivity, and recovery. International Journal of Stress Management, 13(3), 273.
- Salmon, P. (2001). Effects of physical exercise on anxiety, depression, and sensitivity to stress: a unifying theory. Clinical Psychology Review, 21(1), 33-61.
- Sin, N. L. (2016). The protective role of positive well-being in cardiovascular disease: review of current evidence, mechanisms, and clinical implications. Current Cardiology Reports, 18(11), 106.
- Sin, N. L., Graham-Engeland, J. E., Ong, A. D., & Almeida, D. M. (2015). Affective reactivity to daily stressors is associated with elevated inflammation. Health Psychology, 34(12), 1154.