Researchers find out why some stress is good for you
Overworked and stressed out? Look on the bright side. Some stress is good for you.
“You always think about stress as a really bad thing, but it’s not,” said Daniela Kaufer, associate professor of integrative biology at the University of California, Berkeley. “Some amounts of stress are good to push you just to the level of optimal alertness, behavioral and cognitive performance.”
New research by Kaufer and UC Berkeley post-doctoral fellow Elizabeth Kirby has uncovered exactly how acute stress – short-lived, not chronic - primes the brain for improved performance.
In studies on rats, they found that significant, but brief stressful events caused stem cells in their brains to proliferate into new nerve cells that, when mature two weeks later, improved the rats’ mental performance.
“I think intermittent stressful events are probably what keeps the brain more alert, and you perform better when you are alert,” she said.
Kaufer, Kirby and their colleagues in UC Berkeley’s Helen Wills Neuroscience Institute describe their results in a paper published April 16 in the new open access online journal eLife.
The UC Berkeley researchers’ findings, “in general, reinforce the notion that stress hormones help an animal adapt – after all, remembering the place where something stressful happened is beneficial to deal with future situations in the same place,” said Bruce McEwen, head of the Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology at The Rockefeller University, who was not involved in the study.
Stress. The word alone can make someone feel paranoid, edgy and nervous. But is stress really what is wrong, or is it the way you handle your stress that needs to change? People look at the word stress as an enemy that needs to be terminated for good, even though we all know that stress is an inevitable fact of life. So the question is not so much how do you avoid or get rid of stress, but more how do you deal and handle the stress when it does come to surface (because it will)?
Stress is a factor that induces bodily and/or mental pressure and tension. When you read that definition, you automatically assume that it is a bad thing, right? Why? The reason majority of people look at stress as bad is because of the place they take it to when it comes along. When the mind or body has to work a little stress relationshipharder than usual, people fear it because it is not something that is a part of their normal pattern or comfort zone and so that take that stress to a level of where they feel much discomfort and feel painful, angry and depressing emotions and thoughts. So the first step would be to stop being afraid of unfamiliarity or situations where you have to step out of your comfort zone- and start focusing on the positive points of the stress and use it to your advantage.
Kaufer is especially interested in how both acute and chronic stress affect memory, and since the brain’s hippocampus is critical to memory, she and her colleagues focused on the effects of stress on neural stem cells in the hippocampus of the adult rat brain. Neural stem cells are a sort of generic or progenitor brain cell that, depending on chemical triggers, can mature into neurons, astrocytes or other cells in the brain. The dentate gyrus of the hippocampus is one of only two areas in the brain that generate new brain cells in adults, and is highly sensitive to glucocorticoid stress hormones, Kaufer said.
Much research has demonstrated that chronic stress elevates levels of glucocorticoid stress hormones, which suppresses the production of new neurons in the hippocampus, impairing memory. This is in addition to the effect that chronically elevated levels of stress hormones have on the entire body, such as increasing the risk of chronic obesity, heart disease and depression.
Advantages and disadvantages of stress?
Stress can be a motivator. For example, if your’re stressed out because you have a big assignment due, this may motivate you to work on it and complete it. The stress can help you to put in your very best effort. If you’re afraid of losing your job, stress may encourage you to raise your own standards and make improvements you most likely would not have made without the threat of unemployment.
Stress is a disadvantage because it can potentially raise your heart rate and weaken your immune system. Also, it can be a factor in poor decision making because under stress we may not think logically or consider the consequences of the choices we make.
While we all experience stress frequently in our daily lives, not everyone handles it in positive ways. The key for us all is to learn what strategies and behaviors help us to cope with stress in a positive manner.
Less is known about the effects of acute stress, Kaufer said, and studies have been conflicting.
To clear up the confusion, Kirby subjected rats to what, to them, is acute but short-lived stress - immobilization in their cages for a few hours. This led to stress hormone (corticosterone) levels as high as those from chronic stress, though for only a few hours. The stress doubled the proliferation of new brain cells in the hippocampus, specifically in the dorsal dentate gyrus.
Kirby discovered that the stressed rats performed better on a memory test two weeks after the stressful event, but not two days after the event. Using special cell labeling techniques, the researchers established that the new nerve cells triggered by the acute stress were the same ones involved in learning new tasks two weeks later.
“In terms of survival, the nerve cell proliferation doesn’t help you immediately after the stress, because it takes time for the cells to become mature, functioning neurons,” Kaufer said. “But in the natural environment, where acute stress happens on a regular basis, it will keep the animal more alert, more attuned to the environment and to what actually is a threat or not a threat.”
Stress causes chronic fatigue, headaches, back pain and digestive upsets.
It increases blood pressure which increases the risk of having a stroke or heart attack.
Stress makes asthma worse.
Stress triggers poor decisions such as drinking too much, eating too much, smoking, and drug abuse.
Stress makes it harder to make decisions that will improve your health.
Bad stress makes you feel horrible. Now, what about good stress? Yes, you just heard me say good stress. Stress is a natural thing and should occur in our lives to be healthy and productive. That’s right I said that stress makes us healthy and productive. Stress produces hormones that our body uses for energy. Stress produces what we refer to as adrenaline. Adrenaline helps us preform task quickly. The problem is when we overload the system. The problem is when the feeling of stress does not pass through our perspective filter. When we think of stress we instantly think of it as a negative word. So, our mind tells the rest of our body to act accordingly. We become “stressed out.”
You can take the emotions of stress and turn them into a ruined day. You can create many bad decisions as a direct result of how you chose to view stress. You can harm yourself and others. People have allowed stress to put them in the hospital. Stress has caused people to lose their tempers and hurt other verbally and physically. Stress has ruined days and ruined lives.
They also found that nerve cell proliferation after acute stress was triggered by the release of a protein, fibroblast growth factor 2 (FGF2), by astrocytes - brain cells formerly thought of as support cells, but that now appear to play a more critical role in regulating neurons.
“The FGF2 involvement is interesting, because FGF2 deficiency is associated with depressive-like behaviors in animals and is linked to depression in humans,” McEwen said.
Kaufer noted that exposure to acute, intense stress can sometimes be harmful, leading, for example, to post-traumatic stress disorder. Further research could help to identify the factors that determine whether a response to stress is good or bad.
“I think the ultimate message is an optimistic one,” she concluded. “Stress can be something that makes you better, but it is a question of how much, how long and how you interpret or perceive it.”
The eLife paper was coauthored by UC Berkeley colleagues Sandra E Muroy, Wayne G. Sun and David Covarrubias of the Department of Molecular and Cell Biology; Megan J. Leong of the Helen Wills Neuroscience Institute; and Laurel A. Barchas of the Department of Integrative Biology. Kirby is now a post-doctoral fellow at Stanford University.
Kaufer’s research was funded by a BRAINS (Biobehavioral Research Awards for Innovative New Scientists) award from the National Institute of Mental Health of the National Institutes of Health (R01 MH087495) and the National Alliance for Research on Schizophrenia and Depression. Kirby was supported by fellowships from the California Institute for Regenerative Medicine and the U.S. Department of Defense.
###
By Robert Sanders
UC Berkeley