In a riveting Q&A session following a keynote lecture, Dr. Robert Sapolsky, a world-renowned neuroendocrinologist, unveiled some mind-bending truths about stress, cortisol, and health.
"There is this dichotomy between adrenaline sympathetic nervous system and an acute stressful crisis and cortisol chronic stress chronic psychosocial stress", said Dr. Sapolsky.
The Dual Nature of Cortisol
First, the bad news: cortisol has long been vilified as the ultimate villain in stress-related diseases. However, Dr. Sapolsky shakes this belief, pointing out that it's not entirely true.
"What you get is cortisol is the villain in every single scenario of stress-related disease, except it turns out that it's not true."
The truth, according to Sapolsky, is that cortisol operates on an inverse U relationship with health outcomes.
The Cortisol Balance
An optimal level of cortisol enhances immune defenses, oxygen, and glucose delivery to the brain, and even improves memory. The problem arises only when this balance is tipped.
"It is only when you get past the point of it being stimulatory that you fall into the range where it does exactly the opposite."
The balance is personal. It is defined by each individual's stress profile and circumstances that feel overall benevolent. Dr. Sapolsky illustrates this idea using the example of a rollercoaster ride.
"When you get into a roller coaster, you don't get on thinking there's a chance you're gonna be decapitated."
In the optimal cortisol range, transient stressors feel great when they're in a circumstance of benevolence and safety. The stimulation induced by moderate stressors like riding a roller coaster or watching a scary movie is beneficial.
Cortisol, Stress, and Immune System
In an interesting twist, Dr. Sapolsky explains that cortisol has a complicated relationship with the immune system.
"Cortisol most definitively does what it does is suppress the immune system."
However, a moderate increase in cortisol levels enhances immune defenses and inflammation, proving that too little can be as bad as too much.
Analgesia, Autoimmune Disorders, and Stress
Dr. Sapolsky also addressed questions around analgesia and autoimmune disorders in relation to stress. He explains that the challenges lie in individual differences in hormone production and receptor sensitivity.
"As soon as you are sort of wrestling with sort of individual differences in an endocrine realm like this, the usual suspects are either individual differences in how much hormone you're making, releasing beta endorphin or individual differences in the number of receptors."
In the realm of autoimmune disorders, Dr. Sapolsky described the situation as "fiendishly complicated." He noted that stress enhances immune defenses during the onset of stress, but chronic stress suppresses them. Moreover, synthetic versions of cortisol can be used to suppress the immune system, but periods of stress can also increase the risk for flare-ups of autoimmune diseases.
"Severe levels of immunosuppression, severe levels of enhancement do exactly the opposite."
Social Grooming and Health
The influence of social relationships on stress and health also received mention. Dr. Sapolsky highlighted a study showing that grooming another primate was a better predictor of lower cortisol levels than being groomed.
"One very interesting study looking at how much any given primate was grooming somebody else versus how much they were being groomed, how much they were grooming was the bigger predictor of the lower cortisol levels."
This fascinating discussion with Dr. Sapolsky provides an insightful exploration into the intricate mechanisms behind stress and health, underlining the importance of striking a balance to maintain our well-being.
The Lasting Impact of Childhood Stress
The discussion wrapped up with a profound exploration of the impact of early life stress on adult health.
"Here's cutting-edge molecular biology showing why childhood matters and why childhood matters for a long time afterwards."
While early life stress can have long-lasting and even multi-generational effects, Sapolsky emphasizes the importance of environment, suggesting that changing one's environment in adulthood could help modify the impact of these adverse experiences.
In essence, this engaging and insightful Q&A session with Dr. Robert Sapolsky illuminates our understanding of stress, cortisol, and health, and emphasizes the critical role of balance in maintaining our overall well-being.