Can Too Much Stress Make Us Sick?

The Link Between Fight-or-Flight, Health, and Coping

There was a time in human history where the death bells rang if you so much as stubbed succumbed to gangrene. Thanks to the advancement of modern medicine, we no longer worry about this issue. Instead, we worry about mortgages, student loans, deadlines, and how to social distance without going stir-crazy. According to neuro-endocrinologist and MacArthur Genius, Dr. Robert Sapolsky, “we are smart enough to have invented these psychological stressors and then stupid enough to have fallen for them.” Luckily, we still have all the tools to keep things in perspective.

In September 2016, Dr. Robert Sapolsky spoke about his research on how stress affects health, in a fascinating lecture entitled “Why Zebras Don’t Get Ulcers.” He took a topic that is both neuroscientific complex and emotionally difficult to swallow and made it digestible and engaging. Not shying away from the somber urgency of the damage our stressful lifestyles can inflict, Dr. Sapolsky comforted his audience with tangible analogies and comic-relief.

He began the lecture by polling the audience about their family history of cardiovascular diseases, diabetes, stroke, and cancer—all current leading causes of death. Dr. Sapolsky then jokingly asked about the audience’s encounters with leprosy, tuberculosis, and other illnesses that have been nearly eradicated in Western countries that is until he added the flu, to the list, which “no one dies of … anymore.” Little did Sapolsky realize that two years later, a little disease called Coronavirus would force me to write this review in the social isolation. I was reminded that we never know which words get casually thrown around will turn into cruel irony at a moment’s notice.

Having captured the audience’s attention, Dr. Sapolsky proceeded to talk about stressors, e.g. our physical response to something that provokes stress. For animals who depend on avoiding predators or catching prey, a stressor might be something that threatens their survival.

For example, when a lion attacks a zebra, the zebra’s brain triggers a number of physical responses in the body, known as “fight-or-flight.” During this process, the heart to pumps faster, the muscles become stronger, digestion slows, and the brain snaps into focus. Fight-or-flight only lasts for short bursts of time, ending when the zebra either successfully runs away from the lion, or dies trying. When temporary, these responses can be remarkably advantageous to our wellbeing and survival. However, being in fight-or-flight mode for long periods of time can have detrimental consequences, especially when there is no immediate, external threat to justify the stress.

Humans usually do not have bloodthirsty lions chasing them. Instead we have a different definition of stressor: immediate danger, or the thought that we could be in impending danger, such as traffic, general anxiety, or upcoming deadlines. This means that we can still turn on fight-or-flight in response to psychological stressors, even when we are completely out of harm’s way. Long-lasting stress results in the fight-or-flight response becoming worse than the psychological stressor itself.

To explain this, Dr. Sapolsky told a story about Austrian physician Hans Selye, who injected fluids into lab rats to study their digestive system. Every day he would chase them, squeeze them, drop them, and drag them out from under the sink with a broomstick. After months of this, he discovered that all the rats had stomach ulcers from being exposed to such high stress. Selye realized something astonishing about digestive health: the longer a rat’s stress response was activated, the more their stomach was damaged.

To clarify, it is not that the stress response necessarily causes ulcers directly. But when stressed, the stomach stops digesting—which means it also stops processing nutrients and repairing stomach walls. This makes sense in the short-term because if you’re running for your life, it’s not really the time to focus on breaking down that sandwich you had for lunch. However, the longer our stress response persists, the more we delay the digestion process.

Perhaps scariest of all, Dr. Sapolsky went on to say, is the effect that long-term psychological stress has on the brain. In temporary fight-or-flight, our perception is enhanced, memory is sharp, and thinking is quick. However, Sapolsky has found that long-term stress can damage the hippocampus--where memories are processed--by killing neurons and preventing new ones from growing. While the hippocampus withers away, the amygdala--where the brain process fear-- is in overdrive, growing larger, more complex, sending urgent signals to the brain as if the sky were falling at our feet. The changes caused by such long-term wear and tear are often irreversible.

Keep Calm and Cope!

How do we keep our stress in perspective? Ending on a hopeful note, Dr. Sapolsky concludes his lecture and the panel of questions by offering some de-stressing advice. Find outlets and hobbies to release pent-up energy. Try to prepare yourself by anticipating events before they happen. Create a sense of control within your daily routine. Most importantly, however, find other people. We need friends, families, and/or small groups.

“The thing isn’t that we have more stressors. Instead, we have less support now than ever. We move more, we don’t talk to our neighbors, we work longer, we are mobile. Then, when a crisis comes, half of the country realizes we don’t know any of our neighbors because we were too busy being mobile and anonymous, and we don’t have the traditional support.”

In an era of social distancing, this insight has never been more important. If we are to cope with COVID-19, we need quality, loving, mutual relationships; a shoulder to cry on and someone who will cry on ours. After spending twenty years studying this subject, Dr. Sapolsky kept returning to one idea— the thing that saves the body from long-term stress is not social dominance or the hierarchy of status… it’s social support.