Photo by Carolyn Weinstein
By: Nick Perry
When Dr. Robert Sapolsky of Stanford University asked a packed Finney Chapel how many people had a family history of heart disease and cancer on Thursday night, nearly everybody raised a hand. However, when asked about a family history of leprosy and dysentery, all hands went down.
“We are not like normal mammals,” Sapolsky told the crowd. “We don’t get sick like normal mammals, we don’t die like normal mammals.” Sapolsky’s convocation, Why Zebras Don’t Get Ulcers: A Guide to Stress, Stress-Related Diseases, and Coping, discussed the evolution of stress study and how humans have a penchant for causing their own stress.
Stress study is a relatively recent field, explained Sapolsky, and was not fully advanced until scientists began to ask “totally bizarre questions like ‘what’s your psychological makeup,’ or ‘what’s your social status,’ or ‘how are people of your social status treated in society.’” When examining these questions, Sapolsky argued, the exacerbation of diseases can be directly correlated to stress.
When homeostatic balance is lost, animals become stressed and, in the short-term, they turn on the stress response. Humans, however, are a rare animal that turn the stress response on if they “think [their] body is going to be knocked out of homeostatic balance.” Unlike 99% of animals, humans turn the short-term stress response on all the time because they have the capacity to look to the future and complain about it. For this reason, said Sapolsky we are the most vulnerable mammals to stress-related disease.
Sapolsky outlined seven effects of the typical stress response. When an animal is under immediate duress it rapidly mobilizes energy from fat cells, increases its cardiovascular tone, enhances its immune system, sharpens its cognition and alertness, and suppresses digestion, growth, and reproduction. In a stressful situation, all of these steps must occur or, Sapolsky explained, “you’ve got like a 30 second life expectancy.” But humans abuse the stress response and often get sick as they run into what Sapolsky referred to as the “exhaustion phase” when the body is working out of homeostatic balance for too long. While a human will never run out of adrenaline, Sapolsky–in a tribute to Oberlin leftism–argued that the problem is that “after while you’re spending so damn much on your military that you don’t give as much to healthcare and social services.
Sapolsky offered a number of stress-related disorders to each adaptive stress response. By suppressing stress and hostility, disorders such as adult onset diabetes, hypertension, and atherosclerosis can take root in humans. Stress also impairs ability to repair ulcers and suppresses growth. Sapolsky discussed a child who suffered from psychogenic dwarfism while growing up in a stressful, unloving environment, but began to grow when he developed a feeling relationship with a nurse who was studying him. Incredibly, when she left for a two week vacation, the boy stopped growing, only to resume as soon as she returned. This case spoke volumes to the influence of companionship on reducing stress.
Reproductive functions are also thrown off by the stress response, Sapolsky argued. Studies have shown that females under constant stress can begin to run low on estrogen and lose the ability to ovulate. Stressed out males tend to develop erectile dysfunction because, as Sapolsky stated, “In order to get an erection you have to be calm and vegetated.”
Stress can contribute to memory loss, depression, and the endangerment of neuronal development, as well. Since the body releases dopamine when under stress to enhance alertness, if a person is continuously under stress his or her ability to produce a happy feeling becomes inhibited, and neurons can become damaged.
Although stress is related to many diseases, Sapolsky emphatically insisted that it has absolutely no link to cancer as was once thought.
In his concluding statements, Sapolsky presented a study performed on lab rats that examined the development of ulcers on rats in a stressful environment. The experiment put rats in a cage and shocked them at random. The study found that rats who were shocked alone, without warning, were at significantly greater risk of developing ulcers. Meanwhile, rats that were permitted to have an outlet had very reduced chances of getting ulcers. From the study it was concluded that there are specific psychological modifiers to the stress-response. Outlets for frustration, a sense of control, a perception of life improving, and social support can significantly lower stress levels.
Sapolsky reminded the crowd that “none of us are ever going to be stressed running away from saber-toothed tigers, none of us are going to be wrestling for canned food items at the supermarket, instead you’re going to have the luxury to sit around and invent these psycho-social stressors.” He urged people to never be socially isolated because you will become stressed. Humans, Sapolsky claimed, are “smart enough to invent this stuff, and foolish enough to fall for it,” making us very prone to stress-related disorders, and constantly in need of modifiers to the stress-response.