Why Zebras Don’t Get Ulcers

It is only the beginning of the spring semester but I am sure many of us are already feeling “stressed.” This simple word has a large impact on all of us, including myself, and as humans we are constantly trying to find better ways to cope with stress in order to live a healthy lifestyle. Stress has always interested me because of its impact on our health and the long-term effect it can have on our minds and bodies. So when I started to think about the many ways that stress is induced in humans, I also started to wonder about animals…do animals experience the same stress that we do? Is my dog ever stressed? He sure seems happy sleeping 80% of the day and having the freedom to run around outside. When compared to a wild animal maybe his stress level is lower than theirs?

In my Jan Plan class sophomore year we read a book called, Why Zebras Don’t Get Ulcers by Robert M. Sapolsky. In his book, one of the topics he touches upon is the type of stress within the animal kingdom. He describes how wild animals, like zebras, generally experience episodic stress, like running for their lives from a lion. In contrast, a human could also experience episodic stress running from a lion but we generally experience chronic stress that occurs throughout our lifetime. We might worry about a test, experience stress trying to get a job, or become stressed just by sitting in a traffic jam on our way to class or work. Therefore a zebra’s episodic stress does not ultimately lead to stress-related disorders like decreased neurogenesis, ulcers, hypertension, or increased hippocampal neuronal atrophy because their stress happens less often than ours.

Sapolsky explains that as a response to the signals in our brain from the region of the hypothalamus, the adrenal gland will secrete glucocorticoids which will then respond to our stress. Some actions from the glucocorticoids will help mediate the stress response while other actions help re-establish homeostasis. These effects of the glucocorticoids for wild animals are useful when they are running away from their predators because of the fight-or-flight response that is induced. When humans experience the secretion of glucocorticoids at high quantities throughout their lifetime, this is not as helpful for our system and is indeed harmful. Humans are not made to experience the daily stress of getting to a job on time or worrying about making enough money to live comfortably; we are made to experience episodic stress like our fellow animals. So, I learned that since animals experience episodic stress, they are not likely to develop long term negative effects like we do, therefore they would not develop an ulcer. So every once in a while sit back, take a deep breath and relax. Though we experience different levels of stress when compared to wild animals, we should be thankful we don’t have to run for our lives from a lion.

Citation: Sapolsky, Robert M. Why Zebras Don’t Get Ulcers: A Guide to Stress, Stress Related Diseases, and Coping. New York: W.H. Freeman, 1994. Print.

I added a youtube video of Robert Sapolsky talking about this topic if you are interested!

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