Key Points
- Stress has a significant impact on immunity
- Job stress and burnout are implicated in reducing immunity
- Particularly the amount of reward you receive for your efforts is a major factor in how stressed you become and the impact of this on immunity
- Meditation & mindfulness, and exercise reduce stress and improve immunity
Stress has an undeniable and large effect on health and is a less commonly discussed, but extremely important part of encouraging the greatest human resilience and resistance to infections.
A systematic review of 56 studies showed that stress had a significant impact on measures of immunity (reduced natural killer cell activity, NK and T cell subsets, CD4+/CD8+ ratio, and increased inflammatory markers).
Stress has a significant impact on measures of immunity
In particular, the following psychosocial factors of stress were implicated1:
- Job-stress
- Low job control
- High job strain
- Job dissatisfaction
- High effort and low reward work
- Overcommitting
- Burnout
- Unemployment
- Organizational downsizing
- Economic recession
The effort-reward imbalance, in other words, the reward you receive in comparison to the effort required at work, is particularly associated with much higher stress levels, with a demonstrable effect on immunity. Overcommitment or overwork are also associated with reduced immunity. For example, caregivers of dementia patients suffer poorer immune responses and this is considered to be as a result of the demands of their workplace stress,2 but a lower reward-to-effort ratio results in a greater reduction in immunity than over-commitment.3
A lower reward-to-effort ratio results in a greater reduction in immunity than over-commitment
Prenatal stress is also reported to increase the risk of nervous, endocrine and metabolic diseases, along with immune dysfunction. The influence of prenatal stress on the immune system is complicated and includes changes to immune cells, cytokines, and immune organs.4
Effects of stress-reduction on Immunity
A systematic review of 75 studies was conducted to look at the effect of psychological interventions for optimising immune function. Small-to-medium effects were found for the effects of psychological interventions on optimization of immune function. Large effects on immune function were shown for in vivo immune-related challenges in studies which included skin-tests and wound healing, while studies incorporating psychophysiological challenges and in vitro immune-related stimulations also demonstrated better immune responses among those receiving stress-reducing interventions. These findings support the effectiveness of stress-reducing psychological interventions in improving immunity.5
Take-home message
Stress reduces our ability to optimally respond to immune threats. The biggest impact on stress is likely to come from the psychosocial environment and in particular job stress. Out of the subsets of job stress, how much reward we receive for our efforts is the biggest impactor of our stress levels and we should strive to be improving how much reward and perceived value we receive from our work. Also, stress-reduction, in particular mindfulness and meditation, and exercise are keys to improving our relationship with life stress and can mitigate the effects of stress on our immunity.
References
1. Nakata A. Psychosocial Job Stress and Immunity: A Systematic Review. In: Yan Q, editor. Psychoneuroimmunology: Methods and Protocols. Totowa, NJ: Humana Press; 2012. p. 39-75.
2. Whittaker AC, Gallagher S. Caregiving alters immunity and stress hormones: a review of recent research. Current Opinion in Behavioral Sciences. 2019;28:93-7.
3. Eddy P, Heckenberg R, Wertheim EH, Kent S, Wright BJ. A systematic review and meta-analysis of the effort-reward imbalance model of workplace stress with indicators of immune function. Journal of Psychosomatic Research. 2016;91:1-8.
4. Yan W. Impact of prenatal stress and adulthood stress on immune system: a review. 2012.
5. Schakel L, Veldhuijzen DS, Crompvoets PI, Bosch JA, Cohen S, van Middendorp H, et al. Effectiveness of stress-reducing interventions on the response to challenges to the immune system: a meta-analytic review. Psychotherapy and psychosomatics. 2019;88(5):274-86.
