Dr. Dhabhar came to us from the Department of Psychiatry & Behavioral Sciences, and the Sylvester Comprehensive Cancer Center, at the University of Miami Miller School of Medicine. He was the first to discover mechanisms by which short-term stress physiology enhances the body’s immune defenses to increase protection during a fight-or-flight response.
He is interested in developing practical and sustainable interventions to minimize the effects of “bad” stress and maximize the effects of “good” stress. His interests extend from stress-related molecular and cellular mechanisms to their holistic physiological function in individuals, to practical and sustainable implications for public policy and societal well-being.
This month’s seminar had the best turnout yet! Dr. Dhabhar drew a crowd of professors, collages, and students from so many areas here on Dartmouth’s Geisel School of Medicine campus. His intriguing topic generated a swirl of questions and comments from the audience, and conversations continued long after the seminar came to a close.
These are things that struck me (as an utter layman to the topic and associated terms—except for the word ‘stress’…that one I get!) as I listened to Dr. Dhabhar:
Quoting Hippocrates, Dr. Dhabhar said, “It’s far more important to know the person who has the disease than it is to know the disease.” His work is showing people how to maximize mind-body health through hard science psycho-neuro immunology shows us how stress impacts the nervous system, endocrine system, immune system, and overall health, and feeds back to brain creating a loop.
He asked us to consider two things:
1) while “stress is a loaded gun”, has some truth to it, it’s not always.
2) mother nature gave us the stress response to help us survive, not die.
Sometimes we even get stressed on purpose: we go to Halloween haunted houses to get stressed—to get a thrill.
The definition of stress is a constellation of events that begins with a stimulus that precipitates a reaction in the brain that subsequently results in the activation of fight/flight systems in the body. Without the biological stress response, it doesn’t matter; there is no stress.
Short-term stress can last minutes to hours. Chronic stress is weeks to months to years.
Stress affects the heart rate, adrenaline, noradrenaline, cortisol, cytokines—All increase. Some common everyday activities such as exercise and kissing (intimate) also activate this response.
Most research is focused on long-term chronic stress. It is important to investigate and HARNESS the protective effects of short-term stress which affects psychological states, heart rate, blood pressure, hormones, immune cells and factors, functional and health outcomes.
What happens to blood immune cell numbers during short term stress, as some of those events mentioned above, jumping out of an airplane, surgery, and medical procedures? T cells increase just before the surgery begins, decreases during surgery, and everything returns to baseline after surgery. After psychological stressors, things return to baseline 3-4 hours after.
Immune cells are body’s soldiers, when a stress response begins, 1-3 minutes they leave the spleen and enter the blood vessels, resulting in increased lymphocytes and monocytes that enter skin to potential battlefields—they go everywhere (In case a lion bites you!—you know, harkening back to mother natures intended reason for stress: to save your life!) The immune cells are also better able to defend you. But this also means they go to sites of ongoing inflammation, like cardiovascular lesions, which may be a reason for “events.”
What are the factors the distinguish patients who show high vs. low immune cell redistribution during surgery stress: 1. level of chronic stress leading up to surgery. 2. Gender. Women are less able to show adaptive stress and recovery is not as good.
Effects of short-term stress: Mice exposed to UV have lower tumor burden than mice not exposed to stress, especially during the early phases of tumor development, but the effects don’t last forever. If the tumor is already on board, and you pulse the system with stress, you can regress the tumors, until the late stages of tumor.
It’s good for babies to get poked and stressed when injected for immunizations because it stimulates the immune response. In many clinic sites, we want to HARNESS endogenous immune-enhancing mechanisms to augment protective immunity. In patients with inflammatory or autoimmune disease, we need to turn OFF endogenous immunology enhancement to prevent exacerbation of pathological immune reactions. This is one path that stress could exasperate unwanted immune responses.
Chronic stress reduces protective immunity, disrupts day-night biological rhythms & sleep, accelerates aging, and accelerates telomere shortening in response to life stress. In my words: it turns the immune system from protector to killer
Sources of stress (just in case you were wondering): job insecurity, high cost of living, economic uncertainty, relationship conflicts, loneliness, manipulation, and deceit.
Yoda said: Fear is the path to the dark side. Fear leads to anger. Anger leads to hate. Hate leads to suffering. The Dalai Lama basically repeated this message. Chronic stress can drive harmful, feed-forward cycles. What can we do about harmful stress?
How do we break that cycle? By optimizing the stress spectrum. This means minimize or eliminate bad stress. Maximize low or no stress times and events, optimize good stress and shut down the cycle as soon as possible. To stay on the good side of stress, there are things to focus on. Have a good mix of all of the following: LIFESTYLE: sleep, exercise, nutrition. PSYCHO-SOCIAL: coping, social support, authenticity, gratitude, compassion. ACTIVITIES: meditation, yoga, mindfulness, natures, walks, dance, music, art, gardening, fishing, breathing. The activities affect the parasympathetic system by strengthening the calming response, regulating circadian rhythms, biological aging can be slowed down, and the probability dis-regulated responses are decreased.
After his formal presentation, Geisel MED students, and TDI’s MPH and Eichler Fellows students stayed behind for the opportunity to delve deeper and ask Dr. Dhabhar questions over dinner.
Check out photos from the evening here: https://flic.kr/s/aHsmHqRXDM