Economic Stress Linked to Worsening Biological Health, Study Finds
People who experience stressful life events and situations are more likely to have poorer biological health, according to a new study by UCL researchers, as indicated by biomarkers related to the interaction of the immune, nervous, and endocrine systems.
The study, published in the journal Brain, Behavior and Immunity, found that not only major stress experiences, such as bereavement, but also chronic challenges, such as financial strain, negatively affect the healthy interaction of these systems.
Maintaining good health requires communication between the immune, nervous, and endocrine systems. When these processes are disrupted, they can lead to a variety of mental and physical illnesses, ranging from cardiovascular disease to depression and schizophrenia.
When threats such as stress occur, immune, nervous, and endocrine system signals are activated, spurring physiological and behavioral changes.
In this new study, researchers analyzed blood levels of four biomarkers in 4,934 participants aged 50 and older in the English Longitudinal Study of Aging. Two of these were proteins involved in the innate immune response to inflammation (C-reactive protein and fibrinogen) and two were hormones involved in the physiology of the stress response (cortisol and IGF-1).
The researchers used latent profile analysis, a sophisticated statistical technique, to identify clusters of biomarker activity; three groups were identified, low risk to health, moderate risk, and high risk. The researchers then examined how prior exposure to stressful situations affected the likelihood of being in the high risk group.
They found that overall exposure to stressful situations, ranging from being an informal caregiver to having experienced bereavement or divorce in the past two years, increased the likelihood of being in the high-risk group by 61% after four years.
Apart from that, the effect was cumulative: those who experienced two or more stress-inducing situations increased their likelihood of belonging to the high-risk group by 19% for each stressor experienced.
Those who reported only economic strain (the perception that they may not have sufficient financial resources to meet future needs) were 59% more likely to be in the high-risk group four years later.
Lead author Dr. Candidate Odessa S. Hamilton (UCL Institute of Epidemiology and Health Care) said, “When the immune and neuroendocrine systems are functioning well, homeostasis is maintained and health is preserved. Chronic stress, however, can disrupt this biological exchange and cause disease.
We have found that economic stress is most detrimental to biological health.” This may be because this type of stress invades many aspects of our lives and can lead to family conflict, social exclusion, and even hunger and homelessness.
Prolonged stress experiences can disrupt communication between the immune and neuroendocrine systems. This is because the response to stress is similar to the response to disease and activates some of the same pathways (e.g., both responses trigger the production of immune system signals called inflammatory cytokines).
The researchers also looked at genetic variants previously found to affect immune and neuroendocrine responses and found that the association between a stressful living environment and being in a high-risk group four years later was true regardless of genetic predisposition.
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