The Intersection Between Chronic Stress, Trauma, and Immunity

Introduction

On April 23, 2020, The Atlantic published an article entitled “Why Some People Get Sicker Than Others,” in which the author James Hamblin points out the incredible variability of the immune response of different people who contract coronavirus.  Hamblin quotes Robert Murphy, a professor of medicine and the director of the Center for Global Communicable Disease at Northwestern University who noted that when doctors see this kind of variability it has less to do with the virus and more to do with the immune response of the host.

As soon as news of the pandemic first hit the news, we all learned that older and chronically ill people are most likely to get very sick or die from COVID-19.  In mid-April, the Centers for Disease Controls and Prevention released its first official report on who has been hospitalized in critical conditions for COVID-19.  This report illuminated that in the United States, African Americans, Indigenous communities, and Latinos have become critically ill and died at significantly higher rates than white Americans.  Given the fact that African Americans, Latinos and Indigenous communities in the U.S. also have significantly higher rates of some of the chronic diseases known to be risk factors for life-threatening COVID-19 complications combined with the fact that there are severe, long-term disparities for these communities in access to quality healthcare, healthy food and water, and the impact of the chronic stress or trauma faced by these communities, this news was not surprising to anyone who understands that, as Hamblin writes:

Variation in immune response between people is due to much more than  age or chronic disease.  The immune system is a function of the communities that brought us up and the environments with which we interact every day.  Its foundation is laid by genetics and early-life exposure to the world around us—from the food we eat to the air we breathe.  Its response varies on the basis of  income, housing, jobs, and access to health care. . .The people who get the most severely sick from COVID-19 will sometimes be unpredictable, but in many cases, they will not.  They will be the same people who get sick from most every other cause.

This article is an exploration of the complex question of how our external environment—including living with chronic stress and unresolved trauma, overwork, inadequate rest, lack of access to adequate nutritious food, air and water quality, living conditions and much more—impacts the immune system.  My intention in writing it is to pose questions and invite further exploration among both healthcare practitioners, policymakers and individuals who are or wish to become more empowered when it comes to understanding factors affecting their own health.

While the pause of the COVID-19 pandemic and closure of my clinic has provided me with the time to both research and write on this topic, my interest in this subject predates by many years the current pandemic.  I firmly believe that part of what is needed to effectively address the impact of this pandemic is to focus on developing a better understanding of differential immune and physiological responses of individuals exposed to the virus, in addition to better understanding the nature of the virus itself.  I also believe that the relevance of understanding these interactions between external and internal factors on the health of individuals and communities is profoundly important for implementing longer-term and much-needed systemic change in our healthcare systems.

In Chinese medicine, which is where my expertise lies and therefore where I primarily focus in this article, it is a given that for a practitioner to correctly diagnose and prescribe an effective treatment strategy for a patient, she must understand the nature of the pathogenic factor, external and internal factors affecting a patient, and the complicated interactions between the pathogen and a person’s differential immune response.

This holistic approach is not the norm in modern allopathic (Western) medicine, which is frequently characterized by a silo approach that ignores or even denies the existence of the numerous complex interactions within an individual person’s physiology, let alone the interaction between a person’s complex internal and external experiences and his physiology.  However, there are exceptions to this norm in allopathic medicine, especially in the relatively nascent field of psycho-neuro-immunology.  With the caveat that psycho-neuro-immunology is *not* my area of expertise, I do include a discussion of this topic with citations for further exploration.

There is No One-Size-Fits-All Treatment Strategy in Chinese Medicine

As stated above, from a Chinese Medicine (CM)  perspective, understanding differential immune responses to COVID-19 (or any virus) is both essential for correctly diagnosing and for developing an appropriate treatment strategy for any given patient. As a CM practitioner, I benefit from insights first written down by doctors millennia ago, refined by thousands of CM doctors over the course of centuries, and observed in my own clinical practice about the interconnectedness of the body, mind, emotions, as well as the integral relationship between an individual and her environment.  The Chinese medical practitioner must take into account various underlying physiological realities for a given patient, including genetics (or constitution), as well as environmental factors, including lifestyle, diet, and the effects of chronic stress or trauma.

One of the most important ancient Chinese medical texts is the Huangdi Neijing (The Inner Canon of the Yellow Emperor), which scholars date to more than 2,000 years ago. The Huangdi Neijing emphasizes the negative impact on health when one or does not live in alignment with the seasons; fails to exercise restraint in food and drink; doesn’t get adequate rest; “recklessly overworks;” engages in “sexual excess,” and is unable to moderate his emotions.  This medical text sets the stage for a profound understanding of health based on a holistic model of an individual who lives a life of balance in diet, drink, work, rest, temperance in emotional vicissitudes, and lives in alignment with the seasons.  The Huangdi Neijing conversely describes the susceptibility to disease (compromised immunity) of the individual who lives out-of-balance with these natural rhythms.  All subsequent classical Chinese medical texts were based on these simple yet profound principles outlined in depth in the Huangdi Neijing.

Systemic Racism and Structural Inequality in the United States Must Be Factored Into Discussions about Health and Immunity

Today in the United States, many of us are largely detached from living in synch with our natural environment and a great number of us never learned tools with which to regulate our emotions.  However, as an educated white person with the means to follow the Huangdi NeiJing’s ancient guidelines for healthy living, I and people like me, are largely able to choose to implement a version of these guidelines, thereby setting ourselves up for greater resilience and immunity.  In other words, some segments of our unequal society are more readily able to make choices about lifestyle, diet, and learning how to regulate our emotions than others.  Structural racism, inequality and poverty are critically important factors to account for in any discussion about how and why in the U.S. communities of color have higher rates of chronic underlying disease, as well as why they are more vulnerable to becoming critically ill and dying from COVID-19.  As I will outline in this article, chronic stress and trauma (both of which are highly prevalent among Black, Indigenous, Latino and poor communities) adversely impact immunity and increase inflammation, which creates greater vulnerability to becoming critically ill and dying when an individual is exposed to the novel coronavirus.  This fact, coupled with unequal access to quality food, air, water, and healthcare for many black and brown communities in the United States cannot be glossed over, lest any reader is inclined to affix blame on more vulnerable communities for not adhering to “healthier” or “better” lifestyles.

Concept of Immunity in Chinese Medicine:  Wei Qi/Protective Qi

While attempting to make a direct one-to-one correlation between Western and Chinese medicine is impossible, there are many concepts from Chinese medicine that can be explained in terms that a lay reader is able to understand.  In any CM discussion about immunity, we must understand the concept of Wei Qi.  Wei Qi is commonly translated as either Protective Qi or Defensive Qi.  I use all three of these terms interchangeably.  According to CM, our Wei Qi is governed by the Lungs, which spreads Protective Qi throughout the body, specifically to the areas between the skin and muscles.  Wei Qi itself is produced by the combination of the air we breath and the nutrients we absorb from food.  This means that strong Protective Qi (or strong immunity) from a CM perspective derives from a combination of heredity (constitution in CM terminology), good nutrition and healthy digestive function, the quality of the air we breathe, as well as the quality of the breaths we take.  Conversely, weakness or deficiency of Protective Qi results from poor air quality, poor nutrition and/or a weakness in the digestive system that prevents the body from efficiently absorbing and assimilating nutrients.

There are three primary functions of Wei Qi:

1)  It helps to prevent the invasion of exogenous pathogens.  In Chinese medicine terms, these pathogens take the form of wind, cold, heat, dampness and other climactic factors.  In Western medical terms, Wei Qi protects against germs, viruses and bacteria.

2)  It warms and nourishes the body.

3)  It helps to regulate body temperature.

Just as in allopathic medicine, poor immunity leads often leads to greater susceptibility to respiratory illnesses, weak or deficient Protective Qi leads more readily to invasion by external pathogens and a lesser capacity to successfully fight a viral or bacterial pathogen when it moves deeper into the body where it might attach to one or more organs, creating the potential for more serious illness.

CM Perspective:  Impact of Chronic Stress or Trauma on Wei Qi

 In previous articles, I’ve written extensively on Chinese medicine’s understanding of the impact of unmetabolized emotions.  (To date, I’ve written articles on the specific impact of grief, fear, and anger on the body from a CM perspective).  As previously mentioned, the Huangdi NeiJing describes how a person’s emotional regulation or lack thereof is directly connected to her physiology.  This and subsequent classical Chinese medical texts describe in great length how excess or unmetabolized grief hurts the optimal functioning of the Lungs, while excess or unregulated worry negatively affects digestion and metabolization of food.  Excess or unregulated fear hurts the optimal functioning of the Kidneys, while excess or unprocessed anger hurts the optimal functioning of the Liver.  Finally, either over-excitement or a lack of joy (depression) affects the optimal functioning of the Heart.  To use more modern terminology, the Huangdi Neijing and other classical Chinese medical texts recognized thousands of years ago that when individuals undergo chronic stress or acute trauma and lack the tools to address the resulting emotional dysregulation, the impact on immunity and overall physiological function is as potentially harmful as poor nutrition or toxic air quality.

Returning for a moment to the concept of Wei Qi/Protective Qi, the HuangdiNeiJing teaches us that excess or unmetabolized grief over time adversely impacts the capacity of the Lungs, which in turn negatively affects the quality of our breathing, as well as the strength of our Protective Qi.  Similarly, excess worry (specifically of the kind that leads to rumination) negatively impacts our digestive organs, which can lead to less-than-optimal absorption and metabolization of nutrients (among other digestive problems) and also adversely affects the strength of our Protective Qi.  Finally, due to CM’s sophisticated understanding of the interactions between all of the body’s physiological systems, unregulated or excessive fear, anger and overexcitement or depression also affect our Protective Qi, albeit less directly than grief and worry.

Western Medicine:  A Brief Overview of the Connection Between Chronic Stress and Immunity

As mentioned, allopathic medicine, in some corners, has also recognized the impact of chronic stress on our physiology.  Hans Selye (1907-1949), an Hungarian-Canadian endocrinologist conducted pioneering work on the effects of what we now call chronic, unremitting stress on the physiology of our bodies.  Selye is considered the grandfather of the field referred to as “Psycho-Neuro-Immunology,” which focuses on the science of the interactions between the psyche and the body’s nervous system, which in turn impacts the body’s immune, endocrine, digestive and reproductive systems.  Selye coined the term “stress” in its modern usage; he conceived of stress as a wide-ranging biological process in the body that consists of myriad internal alterations that occur when a person perceives a threat to her well-being or safety.  Selye documented in multiple studies that have since been replicated and expanded upon that stress is not just a matter of subjective experience, but rather a set of measurable processes in the brain that set off a host of physiological reactions in the body impacting different physiological symptoms, as well as the functioning of various organs.

Selye first described the hypothalamic-pituitary-adrenal axis (HPA axis), which is a complex system that is designed to maintain homeostasis in the body by: regulating the neuroendocrine and sympathetic nervous systems; modulating immune function; and regulating digestion and metabolism.  The hypothalamus (located in the forebrain) connects the autonomic nervous system and the endocrine system with the pituitary gland (at the base of the brain), which signals to the adrenal glands (atop the kidneys).  The hypothalamus is critical in maintaining bodily homeostasis through regulating sleep, emotions, body temperature, hunger, thirst and more.  The pituitary gland is considered the “master gland” as it regulates other glands of the endocrine system.  The adrenal glands produce important hormones, including cortisol, that mobilize the body for a “fight or flight” response in times of perceived or actual danger.

The various parts of the HPA axis work together like an interwoven web and if one part of the axis is malfunctioning, it affects subsequent reactions throughout the axis. What’s now referred to in Psycho-Neuro-Immunology literature as  “HPA axis dysregulation” occurs when the body continually produces stress hormones.  The HPA axis becomes less sensitive and the system has less capacity to restore the body to homeostasis.

HPA Axis Dysregulation and the Immune System

Broadly speaking, the immune system comprises cells, proteins, organs, and tissues that work together to provide protection against bodily disease and damage.  Healthy or acute stress produces higher levels of pro-inflammatory cytokines, which is a necessary short-term response for eliminating pathogens and initiating healing.  Chronic stress (lasting from days to years) also produces higher levels of cytokines; however, an overload of cytokines in the system leads to systemic inflammation and results in reduced immune function.  Both systemic inflammation and decreased immune function are linked with harmful chronic diseases and conditions, many of which are associated with higher levels of critical illness and death due to COVID-19.

How does chronic, systemic inflammation influence immunity?  Immune cells have receptors for the stress neurotransmitters and hormones, including cortisol, epinephrine and norepinephrine.  As noted, the release of these chemicals ideally prepares the body to mount an immune response when needed to fight a pathogen.  However, under chronic stress, sustained release of these chemicals increases systemic inflammation and decreases the responsiveness to some immune cells, such as lymphocytes.  Over time, increased inflammation and decreased responsiveness of immune cells will lead to systemic changes in our immune response.

Chronic psychological stress has been implicated in altered immune functioning in many inflammatory diseases such as Rheumatoid Arthritis and Irritable Bowel Syndrome.  Chronic stress also has been shown to enhance risk for developing autoimmune disease, which is caused when the immune system misidentifies self tissue as foreign and mounts an attack against it.  Additionally, many individuals with autoimmune disease have demonstrable difficulty in down-regulating their immune responses after exposure to stressors.

Concluding Thoughts and Further Questions:

 In sum, it is my strong view that both Chinese medicine and the more holistic forms of allopathic medicine have much to teach both healthcare professionals and policymakers, as well as individuals about the need to further understand differential immune responses in order to develop more effective and, in some cases, individualized treatment strategies for COVID-19 and other pathogens that are or will be of increased danger to everyone, but especially immuno-compromised populations.  In the longer term, understanding and accounting for the linkages between trauma/chronic stress and resulting emotional dysregulation and immunity, combined with a deeper understanding of the myriad interconnections between immunity and nutrition, regular exercise, environmental factors (air, water, outdoor green space), should inform more nuanced and effective policy strategies focused on systemic changes that could, over time, lead to decreased rates of chronic disease, inflammation, and greater immunity and resilience.  I’m not suggesting that there are any simple fixes, but I am suggesting that the “new normal” everyone keeps referring to during the COVID-19 pandemic could, with the right leadership, smart policy, and cooperation between experts in a variety of fields, look a lot better for a much broader array of people than the old normal.

(For more in-depth research on the work of Hans Selye and the subject of Psycho-Neuro-Immunology, here are some excellent resources:  The Stress of Life by Hans Selye; When the Body Says No by Gabor Mate; The Body Keeps the Score by Bessel Van Der Kook)