An invitation to see social determinants of health in a new light.
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An invitation to see social determinants of health in a new light.
Written by Johanna Lynch – University of Queensland
In this issue on experiencing as a whole person we will reflect on dynamic impacts of life story on health that are relevant to clinical care. This process will be like flying over a landscape (macro population-based studies) and examining each house plan in detail (micro biological studies). It will still not be able to tell us what is going for each person inside their home (the clinical needs) as in many areas, further clinical studies are needed to help us understand the whole person in their context. I hope these thoughts inspire your curiosity about how relationships, context, meaning, story, hope, and justice impact biological health of the whole person.
Patterns of whole person interconnections relevant across the disciplines can be seen across both macro and micro perspectives . Population and public health researchers and those who study social determinants of health (at a macro level), alongside molecular biologists, psychophysiologists, interpersonal neurobiologists, and those who study psycho-neuro-endocrine-immunology (at the micro level) explore the impact of lived experience and relationships on health. Drawn together these studies give insights that could transform healthcare priorities.
Interconnectedness is so difficult to study in a world focussed on siloed disciplines. Insights that change how we understand whole person health usually come from those working on the borders1 – rarely from within the mainstream of an established and powerful discipline. This work done outside established disciplines often does not have funding, knowledge translation pathways, or champions who are respected or valued by the mainstream, and so there can be decades of ignorance between discovery and any changes to practice. 2 Learning from cross-disciplinary research can inspire us to see and care in new ways.
Firstly, a few random insights into interconnections to start – about biological impacts of tickling rats, and kangaroo cuddles for neonates; the ways that stressful marriage and unregulated anger delay wound healing; and the way that the immune threat of COVID-19 impacted those experiencing structural racism. Tickling rats (a proxy for relational touch) is associated with lower stress hormone, lower anxiety measures, and more positive vocalisation and approach behaviours.3 Neonatal units now prioritise ‘kangaroo’ (skin-to-skin) cuddling for preterm infants as it was found to reduce stress hormones, improve oxygen levels, blood pressure, and heart and breathing rates.4 Wounds heal slower (a functional measure of health), and blood levels of the bonding hormone oxytocin are lower if a person is in a stressful marriage5 or if they have difficulty regulating their anger.6 Finally, USA research showed there were more deaths from COVID-19 in communities without household internet and with lower attainment of a high-school diploma, (which, due to structural racism, equated to neighbourhoods with higher percentages of Black residents).7 These snap shots show how tuning into the molecular biology or the population experience can reveal patterns that matter.
Now let us focus on a few patterns within the macro and micro research worlds:
Three insights from population-based research, will show the impact of lived experience on our bodies from a macro angle:
One prospective study, done by Robert Anda’s team, from the USA Centre for Diseases Control, studied the impact of hopelessness on cardiac death in a cohort with no cardiac risk factors or other serious illness.8 He studied 2832 USA adults aged 45-77 and asked them about hope – asking them: In the past month have you felt so sad, discouraged, hopeless, or had so many problems that you wondered if anything was worthwhile? Participants were asked to rate themselves on a six-point scale from “not at all” to “extremely so – to the point that I have just about given up”. After adjusting for demographic and risk factors, this work showed that people with hopelessness were at increased risk of both fatal and nonfatal ischaemic heart disease. This risk was dose dependent – the more hopeless, the more cardiac death and nonfatal heart attacks. This trend was more marked in people of colour, the least educated women, and those who were unmarried. This research was published in 1993 and yet monitoring hope as an important outcome of therapeutic care is still not usual practice.
The second area of population-based research that helps us to notice the impact of lived experience on the body is from those who study social determinants of health.9 Social determinants of health are defined as “the conditions in which people are born, grow, work, live, and age, and the wider set of forces and systems shaping the conditions of daily life”.10 It includes structural inequities in power, money and resources as well as practical things like crowding, noise, poverty, food insecurity, low education, unemployment and job insecurity, social exclusion, racism, sexism, discrimination, and war. In our own community, colonisation and dehumanising public policy have changed health outcomes of First Nations people. Those who study the biology of the social determinants of health ‘exposome’ would contend that exposure to social inequity has more impact on health than healthcare.11 They mention increased chronic inflammation, neurodegeneration, infection, cancers, cardiometabolic and autoimmune diseases.11 Health disparities in communities that endure inequity are patterns that should change clinical assessment and policy priorities across sectors.12-14
The third body of research is the Adverse Childhood Experiences (ACE’s) research that started with Vincent Felliti (an American physician) and Robert Anda (a population scientist). They studied 9503 Californian adults who reported childhood experiences of maltreatment and followed them forward for decades to monitor risk behaviour, health status, disease, or death.15-18 They were interested in the prevalence and impact of a history of childhood psychological, physical, and sexual abuse; violence against the mother, or living with household members who were substance users, mentally ill, or suicidal, or ever imprisoned. They were also interested in the links to health risk factors and health outcomes. They found a dose-relationship between number of childhood adversities and prevalence of health risk behaviours (including smoking, severe obesity, physical inactivity, depressed mood, suicide attempt, alcoholism, drug use, > 50 lifetime sexual partners, and history of a sexually transmitted disease).15 Independent of these risk factors, their publication in 1998 also showed a direct impact on health – they showed a dose-dependent relationship between the number of ACE’s and ischaemic heart disease, cancer, chronic bronchitis, emphysema, history of hepatitis or jaundice, skeletal fractures, and poor self-rated health.15 More associations have been documented since – including FMRI studies showing changes to the brain associated with ACEs.19 In their original paper, Felitti and Anda also predicted that medicine would have difficulty attributing physical disease to psychological wounding and adult disease to childhood experiences.15
In 2002, Vincent Felitti expanded on this in a paper detailing how the health of a child can deteriorate into adult sickness , saying “we have shown that adverse childhood experiences are both common and destructive. This makes them one of the most important, if not the most important determinants of health and well-being of the nation.” 17p.46 He also added: “Unfortunately, these problems are both painful to recognise and difficult to cope with. Most physicians would far rather deal with traditional organic disease…comfortably focussed on tertiary consequences far downstream… the primary issues are well protected by social convention and taboo … we have limited ourselves to the smallest part of the problem: the part where we are comfortable as mere prescribers of medication.” 17p.46
The recent Australian Childhood Maltreatment Study has confirmed many of Felitti and Anda’s findings. It has confirmed through telephone interviews with 8500 representative adult Australians who report that before the age of 18 years old they have experienced physical (32%), sexual (39%), emotional (31%) abuse, and exposure to domestic violence (40%).20 This study also confirmed the link to increased physical and mental illness and increased use of the health system.20
Inequities and maltreatment impact life expectancy – they are inscribed on the body,21 and yet we do not routinely integrate social determinants of health into clinical understanding of disease. We rarely understand the importance of justice, community development and empowerment to health.
The other area of research that can help us to see new patterns, is those who study molecular, cellular, or structural systems of the body. A key embodied form of research is the stress research that started with Hans Selye describing ‘eustress’ (tension that can lead to growth), and ‘stress’ (physical changes in the body in response to internal or external ‘stressors’).22 He originally noticed that people in hospital with different diseases seemed to be trying to adapt in similar ways – with fatigue, loss of appetite, fever, and weakness – which he called ‘stress’. This body of research has developed over the years into those who describe ‘positive’, ‘tolerable’, and ‘toxic stress’ (described as “a physiologic memory or biological signature that confers lifelong risk well beyond its time of origin”23p. E238).
There is now an exploding body of research trying to work out how life experience impacts the body. We all know that life stresses impact a person’s health. We have seen people’s tired worn-out faces and know they have had a ‘hard life’. This is now being confirmed at a cellular level as we learn how stressors impact our body. Psycho-neuro-endocrine-immunology research clarifies that all forms of threat have an impact: “the disparity between physical and psychological stressors is an illusion. Host defence mechanisms respond in adaptive and meaningful ways to both.”24p.114
The stress research includes explorations into molecular changes in cellular energy and sugar management (linked to diabetes, fatigue, DNA changes, aging and cell death)25-29, changes in brain connectivity and neurodevelopment30 (linked to capacity to self-soothe, learn, and perceive accurately), autonomic nervous system reactivity (connected to cardiac risk31, and irritable bowel32), cranial nerves (linked to hearing, learning, and social connectedness33), and the immune system34,35 (connected to asthma36, dermatitis37,38, infection and cancer39 risk). Importantly, toxic stress becomes tolerable stress if another safe person is able to buffer the effect of the stressor.40
Allostatic load was named by Bruce McEwen’s team – to describe a theory of how stressors changed the body.41 He theorised that the body started in homeostasis where it could keep the body stable in its context, but then when the stressors started to impact, the body moved into ‘allostasis’ where it was trying to adapt, and then final into ‘allostatic overload’ when it couldn’t adapt anymore and permanent changes started to lead to disorder and disease.
A way to explain this is to think about our knees – when we are young our knees can jump and run and twist (and shout!) (homeostasis), if we put on weight (the stressor), the muscles around our knees adapt – they become stronger and ready to protect and move the knee (allostasis). If we continue to gain weight the muscles around our knees will not be able to adapt enough – and predispose us to injury to the cartilage and knee arthritis (allostatic overload).
This very ordinary process in our knees is played out in the molecular complexity of every cell in our bodies as we age or are overloaded by stressors. Allostatic overload due to stressors causes multisystem physiological dysregulation that impacts metabolic, cardiac, immune and neuroendocrine systems.42 It is especially important in disadvantaged communities with a known health gap where there are daily stressors, including racism.43
Another key growing area of research has come from a psychophysiologist who started out studying low heart rate in premature infants – Stephen Porges.44 This work led to an understanding of heart rate variability45 that is how stress is measured in smart watches! His work has become very important in the trauma treatment community. He now studies the autonomic nervous system that organises our bodily temperature, oxygen levels, blood flow, thirst, hunger, and so much more – all while we are barely aware of it. You may have heard talk of the vagus nerve’s role in mental health? The vagus nerve is a cranial nerve that originates in the brainstem – it receives (afferent fibres) and sends (efferent fibres) messages to the face, larynx, ear, oesophagus, heart, lungs, spleen, kidneys, adrenals, pancreas, and gastrointestinal system. Part of its impact on wellbeing is that it has been implicated in effects of the microbiome on mental health. 46
Stephen Porges’ work into the structure of the vagus nerve has shown that our body automatically monitors for threat all the time even when we are not aware (he calls that ‘neuroception’47), it activates for fight or flight, or it shuts down (‘freezes’) if life threatening danger occurs. He has also shown that when we feel safe, our body can have needed restful restorative sleep, and we can also feel relaxed and sociable with other people. He has called this the Social Engagement System48 that may help us understand the important way that relationships impact health.
A final word from modern stress researcher Robert Sapolsky – from his great book – Why Zebras Don’t Get Ulcers:
“Something akin to love is needed for proper biological development and its absence is among the most aching, distorting stressors that we can suffer. Scientist and physicians and other caregiver have often been dim at recognising its importance in the mundane biological processes by which organs and tissues grow and develop.”49p.98
So – as we come to the end of this flight over the landscape (macro view), and exploration of each house plan (micro view), can we end with a reflection on the life of each person in their home? Let’s reflect on how magnificently life experience and adaptive responses of our biology are woven together and how important love and connection are to health. 49,50 We can be more aware of how our bodies are impacted by injustice, fear, life experience, maltreatment and adversity, hope, relationships, and by the absence of ‘something akin to love’49. I want to also remember with thankfulness all the places my knees have taken me – all the kneeling with children in grass, all the joyful dancing, and stunning mountains they have climbed. What are you thankful for in your body and the experiences it has weathered?
The author would like to thank Dr Rubayyat Hashmi for helpful comments on an earlier draft.
About the writer
Dr Johanna Lynch MBBS PhD FRACGP FASPM Grad Cert (Grief and Loss) is a retired GP who writes, researches, teaches, mentors and advocates for generalist and transdisciplinary approaches to distress that value complex whole person care and build sense of safety. She is an Immediate Past President and Advisor to the Australian Society for Psychological Medicine and is a Senior Lecturer with The University of Queensland’s General Practice Clinical Unit. She spent the last 15 years of her 25 year career as a GP caring for adults who are survivors of childhood trauma and neglect. She consults to a national pilot supporting primary care to respond to domestic violence.
The ALIVE National Centre is funded by the NHMRC Special Initiative in Mental Health.
The ALIVE National Centre for Mental Health Research Translation acknowledges the Traditional Owners of the land on which we work, and pay our respects to the Elders, past and present. We are committed to working together to address the health inequities within our Aboriginal and Torres Strait Islander communities.
WARNING: Aboriginal and Torres Strait Islander viewers are warned that this site may contain images and voices of deceased persons.
This map attempts to represent the language, social or nation groups of Aboriginal Australia. It shows only the general locations of larger groupings of people which may include clans, dialects or individual languages in a group. It used published resources from the eighteenth century-1994 and is not intended to be exact, nor the boundaries fixed. It is not suitable for native title or other land claims. David R Horton (creator), © AIATSIS, 1996. No reproduction without permission. To purchase a print version visit: https://shop.aiatsis.gov.au/
The ALIVE National Centre for Mental Health Research Translation is funded by the National Health and Medical Research Council (NHMRC) Special Initiative in Mental Health GNT2002047.