Allostatic Load

Each moment we clash with internal (thoughts) and external events that challenge our systems. These repeated exposures create flashes of stress, knocking our bodies out of homeostatic balance. Our bodies are equipped with operation systems that promote adaptation to the disruptions, reacting to regain balance by preparing the body and executing behaviors in response to the challenges. When we fail to respond, stress accumulates creating what is called in psychology a heavy allostatic load.

When we are walking alone down a dark street, a passing shadow may activate our stress response—our heart speeds, our muscles tighten, our attention focuses. Our body is ready to flee or fight to regain safety. Of course, stress is induced by many other incidents beyond physical safety. We may experience stress while balancing our budget, or arguing with our spouse. Life threatens on a variety of levels; and those threats spark stress.

Science has identified the autonomic nervous system and the hypothalamo-pituitary-adrenal axis as primary contributors to this preparing and balancing process. The systems are known as allostatic systems and the process as allostasis.

Allostatic Load

Allostatic systems don’t operate without costs. Adaptation to regain balance requires energy. Stress is blamed for many illness and diseases—heart disease, cancer, asthma, GI disturbances, the common cold (McEwan, 1998).

While are allostatic processes keep us balanced, they exact their toll, drawing from critical resources. More stress leads to less energy available for other life functions. Our bodies, when over-taxed, become vulnerable to physical and mental illness. Drained of critical resources we fail to meet many other life challenges.

The cumulating effects of stress from common and major life challenges is referred to as allostatic load. When we operate efficiently, meeting challenges, arriving at solutions, and succeeding in the major demands of life, the allostatic load is manageable. We minimize the ill effects, and benefit from a well functioning system.

What Are Stressors?

Stressors are physical and psychological threats to safety, status, or wellbeing. Most notable are the physical and psychological demands that exceed available resources to adequately respond (Rabey & Moloney, 2022).

Stressors are magnified in unpredictable environments where events conflict with our expectations. Chaos creates a heightened awareness, easily jolting biological reactions, creating stress.

When stressors accumulate quicker than our ability to process and return to homeostatic balance, our allostatic load accumulates.

Allostatic Overload

When the accumulation of stress (allostatic load) exceeds our ability to cope, then we enter a state of allostatic overload, where vulnerability is heightened, and the smooth operation of system may begin to malfunction, failing to respond adequately to life challenges.

Physical and Mental Illness and Allostatic Load

Illness typically not traced to a single cause. Even when we can identify the precipitating event that triggered the illness, the event alone is not the sole cause. Pain, disease, and illness reflect a “complex, dynamic, emergent process whereby multiple factors contribute to an outcome and seemingly small triggers can evoke powerful responses” (Rabey & Moloney, 2022).

We have a basic biological reaction to stress “irrespective of the agent used to produce stress” (Selye, 1951). When stress remains unresolved, stressors lead to disease (Murphy, 2021). 

Hans Selye pioneered the stress disease theory. He hypothesized that “stress is a major cause of disease because of the long-term hormonal changes stress causes in the body.” Selye taught that that “the body has a limited supply of adaptive energy with which to deal with stress and that this amount declines with continuous exposure.” In line with allostatic load, Selye’s theory proclaimed that  “when there has been trauma, stress levels are chronically high and the body loses its capacity to adapt or recover, leading to adrenal fatigue and exhaustion” (Heller & LaPierre, 2012, Kindle location 1,768).

Lucy Prior wrote, “repeated exposure to such stressful environments result in “wear and tear” on the body and this weathering can negatively influence health, a process captured through the concept of allostatic load” (2021).

Three Types of Allostatic Load

Bruce McEwen coined the term allostatic load. He was an American neuroendocrinologist and head of the Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology at Rockefeller University.

According to McEwen’s stress theory, allostatic loads increase and cause problems when any one of three circumstances occur:

• Frequent Stress
• Failure to Shut down
• Inadequate Response

Frequent Stress

When our allostatic system is overworked, the allostatic load accumulates. Our bodies fail to productively process the constant flow of stress. the load increases and our bodies pay a price.

Consider hiking up a steep hill. You have sufficient energy to make it to the top. Now consider hiking up the hill with a backpack. As you begin the ascent, every few feet you place a heavy boulder in the backpack, eventually the weight of the backpack exceeds your strength to accomplish the climb.

Exposure to stressful events that exceed our ability to process eventually accumulate and the allostatic load overwhelms, expressing the overwhelm in physical and psychological ways.

Failure to Shut Down

Failure to shutdown stress responses refers to the inability to process a stressful event efficiently. The individual suffers prolonged elevation of blood pressure or a hypersecretion of cortisol after a physiological stressor.  While their life stressors may not exceed normal experience, the physiological experience of stress is heightened because the body continues to respond to the event as if they are still threatened long after the threatening event has ran its course.

This phenomenon is expressed through excessive rumination, and may culminate in illnesses such as depression.

McEwan explains, the “persistently elevated blood pressure and glucocorticoids accelerate obesity and type II diabetes; persistent glucocorticoid elevation and/or excitatory activity in the brain causes dendritic atrophy and neuronal death in the hippocampus; blood pressure elevations in repetitive, time pressured work” (1998, 2000).

The constant and perpetual existence of stress rips through our brains, eating away and core structures, creating new vulnerabilities, and worsening abilities to process new stressors. When systems do not shut-off, in time, they promote pathologies. This state describes a stress response system that is unable to respond adequately to stressors. Suprizingly, research has discovered that failure to consciously recognize emotion doesn’t eliminate heightened arousal. Our biological organism still is impacted.

Inadequate Response

Diseases such as alexithymia and emotional detachment have their own collection of physical and physiological baggage that interferes with wellness. Since normal avenues of healthy response to stresses are blocked, the body adapts by elevating activity on other systems. McEwan explains that failure to respond to a challenge may lead to “autoimmunity and inflammation and possibly chronic fatigue syndrome and fibromyalgia” (1998).

Subjective Interpretations and Allostatic Load

Stressors are real identifiable events. They can be internal such as thoughts or memories or external such as losing a job or an unexpected bill. However, a stressors impact on the individual varies. We view events differently. We interpret their meaning and these interpretations may magnify or minimize the experience of stress. 

Many therapies, based on cognitive-behavioral model, work to minimize stress by improving subjective interpretations.

Interpretations may enhance of minimize stress. Life, however, is stressful. Some events are difficult to process. We must also find ways to regulate stress that involves accepting the event as stressful and working through the discomfort.

Allostatic Load and Genetics

We are built different. We experience stress differently. Our stress response is more than a difference in subjective interpretations. We inherent a genome that varies in resilience or sensitivity.  According to the The diathesis–stress model disorders develop as a result of interactions between pre-dispositional vulnerabilities (the diathesis), and stress caused by life experiences (Murphy, 2021).

Epigenetics are at play here, activating dispositional vulnerabilities when allostatic loads exceeds an individuals ability to cope. Consequently, constantly experiencing high allostatic loads tands to activate dispositional vulneribilities.

Lightening Our Allostatic Load

We can lighten our load in several ways, improving present and future health.  Healthy stress management begins with implementing other behaviors that strengthen our bodies and minds. Basically, we can’t shortcut around the basics principles of wellness. When we get enough sleep, consume healthy foods, and exercise, we resiliently regulate and process stressors when we get enough sleep, consume healthy diets, and exercises regularly. The big three (sleep, diet, and exercise) are indispensable tools in managing allostatic loads.

These are defocusing practices that can temporarily pull attention away from the stressor, allowing the body to reset, return to a homeostatic balance where effective problem solving cognitions can thrive. Others provide and invaluable resource. We can draw upon their soothing calmness. Connection can fire internal secretion of oxytocin which effectively counteracts the heighten cortisol associated with stress.

Linda Graham, a marriage and family therapist, mindfulness teacher, and expert on the neuroscience of human relationships, explains “the hormone oxytocin is the neurotransmitter of the ‘calm and connect’ response and is the brain’s direct and immediate antidote to the stress hormone cortisol” (2013). Not all stressors are inevitable. Some are direct consequences of choice. We can structure budgets, relationships, and environments to eliminate many of the stressors that vex our lives. By choosing what and when to invite stress, we can more effectively manage the unplanned stressors when they come.

A Few Words by Psychology Fanatics

Research strongly supports theories suggesting stress negatively impacts our physical and mental health. Flourishing requires managing stress, regulating intensities and length of stressful events. 

References:

Graham, Linda (2013). Bouncing Back: Rewiring Your Brain for Maximum Resilience and Well-Being. New World Library; 1st edition​

Guidi J, Lucente M, Sonino N, Fava G, A. (2021) Allostatic Load and Its Impact on Health: A Systematic Review. Psychother Psychosom

Heller, ​Laurence; LaPierre, Aline (2012). Healing Developmental Trauma: How Early Trauma Affects Self-Regulation, Self-Image, and the Capacity for Relationship. North Atlantic Books; 1st edition

​McEwen, B. (1998). Stress, Adaptation, and Disease: Allostasis and Allostatic Load. Annals of the New York Academy of Sciences, 840(1), 33-44.

McEwen, B. (2000). Allostasis and Allostatic Load: Implications for Neuropsychopharmacology. Neuropsychopharmacol 22, 108–124. 

Murphy, T. Franklin (2021). General Adaptation Syndrome. Psychology Fanatic. Published 11-12-2021. Accessed 4-9-2022.

Murphy, T. Franklin (2021) Diathesis Stress Model. Psychology Fanatic. Published 9-7-2021. Accessed 4-9-2022

Prior, Lucy (2021) Allostatic Load and Exposure Histories of Disadvantage. The International Journal of Environmental research and Public Health.

Rabey, M., & Moloney, N. (2022). “I Don’t Know why I’ve Got this Pain!” Allostasis as a Possible Explanatory Model. Physical Therapy, AdvanceArticle, 1-1.