Health TEDTalks

Stress as a positive: Recent research that suggests it has benefits

Aerialist Nik Wallenda looks down and sees the 1,500-foot drop to the bottom of the Grand Canyon below him. All that stands between him and a lethal landing is the 2-inch tightrope that he has decided to traverse on camera, the moment being broadcast around the world on live television. If most people were to rank the most stressful events of their life, this would very likely be near the top of the list. But Wallenda thrives on stress of this magnitude.

In June, Wallenda balanced his way across a quarter-mile gap in the Grand Canyon. And with his feet firmly back on the ground, he shared how he is able to perform stunts like this: by seeing the physical manifestations of stress as positives. Yes, the body will start to shake on the tightrope. But this is not a sign of weakness; it is instead a natural response that is preparing him for what is to come. In moderate amounts — and perhaps this comes with decades of training — stress can be helpful in willing strength and focus when it is needed most.

Kelly McGonigal: How to make stress your friend Kelly McGonigal: How to make stress your friend In today’s talk, given at TED2013, health psychologist Kelly McGonigal reveals a similar approach to stress. She shares a fascinating idea: that the harmful effects of stress may be a consequence of our perception that it is bad for our health.

“Can changing how you think about stress make you healthier? Here the science says yes,” says McGonigal. “Your heart might be pounding, you may be breathing faster… but what if you viewed them as signs that your body was energized and it’s preparing you to meet this challenge.”

McGonigal says that a paradigm shift when it comes to stress could literally be life saving. In this talk, she shares some of the research behind her conclusion. Below, we’ve rounded up some of the studies she mentioned, as well as some further research that hints at some surprising upsides of stress. 

Stress may actually be correlated with longevity—if a person doesn’t view it as a negative

The study: Researchers at the University of Wisconsin-Madison asked almost 29,000 people to rate their level of stress over the past year as well as how much they believed this stress influenced their health — a little, a moderate amount or a lot. Over the next eight years, public death records were used to record the passing of any subjects.

The findings: People who reported having high levels of stress and who believed stress had a large impact on their health had a whopping 43% increased risk of death. On the other hand, those that experienced a lot of stress but did not perceive its effects as negative were amongst the least likely to die as compared to all other participants in the study.

Further reading: Check out this paper, “Does the perception that stress affects health matter?” And these two similar studies back up the idea: (1) “Increased risk of coronary heart disease among individuals reporting adverse impact of stress on their health: the Whitehall II prospective cohort study” (2) “Meta-analysis of perceived stress and its association with incident coronary heart disease.”

A possible antidote to negative effects of stress: giving to others

The study: Lead author Michael J. Poulin of the University of Buffalo and his team interviewed almost 850 people, ages 34-93, living in Detroit, Michigan. Participants were asked to report stressful events they had encountered in the past year and how much, in the same time period, that they had assisted others.  Deaths that occurred within the group in the next five years were tracked using obituaries and public death records.

The findings: Every major stress event increased an individual’s risk of death by 30%. But, overall, this increase was erased for those who reported high rates of helping others, even if they additionally dealt with a lot of stress. The evidence suggests that giving to others significantly reduces stress-induced mortality.

Further reading: “Giving to others and the association between stress and mortality”

Moderate stress can lead to cell growth in the brain’s learning centers

The study: In this 2013 study out of University of California, Berkeley, adult rats were immobilized in a small space for three hours or left unchanged. Two days and then two weeks later, the rats were given a fear-conditioning test, which evaluates the rats freezing or avoidance behavior when in a context that last lead to a negative consequence such as a shock. The measure is known as ‘fear extinction memory.’

The findings: The immobilized rats showed an increased level of the stress hormone corticosterone (the rat equivalent of cortisol in humans) as well as an increased growth of neural stem cells in their hippocampus, an important learning center of the brain. As compared to the control group, these rats had similar results on the fear extinction memory test given two days after the initial stressor, but showed significant improvement on the test after two weeks. The authors put fourth that these newly proliferated cells, after taking multiple days to integrate to fullest capacity, helped in learning at this improved level. Overall, it suggests that moderate levels of stress enhanced neural function and learning.

Further reading: “Acute stress enhances adult rate hippocampal neurogenesis and activation of newborn neurons via secreted astrocytic FGF2”

Stress can summon helper hormones to vulnerable areas

The study: A small amount of stress has previously been found to initiate the redistribution of immune cells, which is thought to aid in survival by sending protection where stress is occurring. Researchers at Stanford University set out to learn more about the shifting levels of these cells, like white blood cells, over time and how different stress hormones trigger the response. Rats were either restrained for a random period from two minutes to two hours or injected with stress hormones (epinephrine and corticoterone) to mimic the effects of such an event. Blood samples were collected throughout.

The findings: The restraint experience and the injection brought on consistent patterns of mobilization in the rats. For example, after the actual stressor, the concentration of a majority of immune cell types monitored followed a pattern of increase and then subsequent decrease in the rat’s blood. Further, specific hormones stimulated unique reactions in a subpopulation of immune cells. By understanding this system, researchers hope to crack the code that would predict which hormone to administer in order to stimulate immune cell aggregation in a specific vulnerable region, just as the body does naturally in response to acute stress.

Further reading: Read the study, “Stress-induced redistribution of immune cells–from barracks to boulevards to battlefields: a tale of three hormones.” And watch the TEDx Talk from the lead author called “The positive effects of stress.”

Stress can induce both good and bad habits

The study: Do you bite your nails, change your eating habits or fall back into addictive dependencies when you are stressed? It is commonly thought that the pressures and anxieties of life are a major initiator of such bad habits. Scientists from the University of California, in the first of five experiments, asked 65 students to record what section of the newspaper they read and what they ate for breakfast over a period of several weeks. Reports for the first three weeks were used to determine habits to then compare data from the next four, a time when the presence of exams lead to depleted willpower. A separate group of students rated breakfast and newspaper options on a scale based on desirability (with the most desirable being the goal), specifically based on which were healthier or more educational, respectively.

The findings: By comparing the students’ choices in more and less stressful periods to the more desirable actions, it was observed that when willpower is depleted, people often return to their habits regardless of its effect on reaching a goal. Importantly, however, the action that became repeated for each individual could be either harmful or helpful –it simply depended on whether it sincerely is a natural tendency. This suggests that breaking a bad habit is most successful when more willpower is maintained, but that times of less control may not be so bad if there are some good habits to fall back on.

Further reading: “How do people adhere to goals when willpower is low? The profits (and pitfalls) of strong habits

A stress-is-enhancing mindset may have lasting effects

The study: Employees at a financial institution were asked to take a test on their stress mindset before and after watching three videos over the course of a week that either presented stress as enhancing or harmful. In a second study, students who had previously taken a survey on their stress mindset were told in class that five of them would be randomly selected to give a speech that would also be videotaped. For each student, mouth swabs were taken to measure cortisol levels. Each was also asked to decide, if chosen to speak, whether or not they would receive feedback from their peers and business school experts who watched the footage.

The findings: In the first study, not only were many people influenced by the message of the videos. Those that viewed the video that approached stress as enhancing reported better work performance as well as less psychological complications. As for the students, those who naturally saw stress as helpful had a more moderate cortisol response upon hearing about the speech possibility — and they were more likely to request feedback.

Further reading: “Rethinking stress: the role of mindsets in determining the stress response”

Kelly McGonigal asks the TEDGlobal 2013 audience how much stress they've experienced in the past year. Photo: James Duncan Davidson

Kelly McGonigal asks the TEDGlobal 2013 audience how much stress they’ve experienced in the past year. Photo: James Duncan Davidson