How Stress Affects the Body
There’s an incredible amount of stress out there these days. In a recent survey, 80 percent of Americans reported that they are beyond frazzled. Stress not only wreaks havoc on us emotionally, it also has a powerful effect on our bodies and our brains, literally aging us before our time, according to groundbreaking research. The happy news: The damage appears to be reversible — and the most effective weapon is exercise.
Your Body on Stress
Why are we so frenzied today? One answer is that “there’s more pressure to compete, and all the technology that brings work home means we never get any respite,” says Michael G. Wetter, PsyD, a Pleasanton, California-based clinical psychologist and diplomat of the American Psychotherapy Association.
The constant grind exacts a physical toll. “Stress has been linked to heart disease and high blood pressure, and it’s a risk factor for type 2 diabetes,” says Wetter. Our bodies are biologically programmed to respond to challenges by releasing a flood of the hormone cortisol, prompting what’s called the fight-or-flight response. “When our bodies and minds perceive danger, blood pressure goes up and the digestive system shuts down,” explains Wetter. The problem is, given the chronic stress so many of us experience today, “the body never has a chance to recuperate,” he says.
Just ask Rachel Capaldi, 26, an assistant bank-office manager in Shelby Township, Michigan. The pressure of holding a full-time job while going to school left her overwhelmed. To cope, she binged on junk food; in eight months, she gained 22 pounds. By 7 p.m. every night, Rachel says, she was exhausted and ready for bed. “I felt a lot older than my years.”
No wonder. In a study of moms, two-thirds of whom were dealing with highly stressful situations, those who reported the most stress “had immune cells that looked as if they’d aged an additional 10 years or so,” says Elissa Epel, PhD, an assistant professor in residence in the department of psychiatry at the University of California, San Francisco. “An aged immune system doesn’t function as well, which may contribute to the body aging.” Stress also seems to alter our hormones, creating an imbalance between those that are anabolic (promoting tissue growth, lean mass, and bone) and those that are catabolic (breaking down bone and tissue for fuel). As a result, says Epel, our insides age faster than we do.
Your Brain on Stress
Mentally we’re also at risk when stress levels skyrocket, and the damage can be dramatic. Stress can cause “structural and functional remodeling in the brain,” says Bruce McEwen, PhD, Alfred E. Mirsky professor in the laboratory of neuroendocrinology at Rockefeller University in New York City. Much of the devastation happens in the hippocampus, a region that’s vital to learning and making new memories. In one study, people with high levels of cortisol had a hippocampus that was 14 percent smaller than those whose cortisol levels were normal, and their memory was also impaired.
And stress can make us…s l o w. In tests, rats and mice that were stressed for several weeks took longer to learn new tasks than those who weren’t, because their hippocampal nerve cells had atrophied. At the same time, the amygdala, the section of the brain that controls physical reactions, had grown larger, making the animals more anxious and aggressive. In other words, keep your stress level high for long enough and you will lose some ability to think — and to calm down.
Sleep and Sweat
All the stressors in your life aren’t likely to just disappear, but there is a way to stop and even reverse the damage they do. Start by getting enough sleep. Lack of shut-eye boosts cortisol levels and can lead to metabolic imbalances that increase your risk of heart disease. Eat plenty of antioxidant-rich fruits and vegetables and cut back on fat. And find time for friends and loved ones. Strong social support — surrounding yourself with people whom you can confide in — makes coping with stress a lot easier.
Finally, and most important, is exercise. It can help stabilize our bodies’ stress-related hormonal imbalance, researchers say. “Fitness increases anabolic hormones, such as growth hormone, and may reduce the effects of cortisol,” explains Epel. “It’s one of the most potent anti-aging behaviors we know of.”
Exercise is especially beneficial for the brain. In research on mice, “We found that physical movement could double, triple, and sometimes quintuple the number of cells in the hippocampus,” says Fred H. Gage, PhD, a professor in the laboratory of genetics at the Salk Institute for Biological Studies in La Jolla, California. “It was pretty surprising.” How does it cause such incredible changes? One possibility is that “during exercise, you generate new blood vessels, which allows proteins to get into the brain,” says Gage.
Another theory is that exercise increases the levels of a protein called brain-derived neurotrophic factor (BDNF) — aka brain fertilizer — “which helps the regeneration of damaged nerve cells in the brain,” says Fernando Gomez-Pinilla, PhD, a professor of neurosurgery at the UCLA David Geffen School of Medicine.
Evidence suggests that people can benefit from working out as much as animals do. In a study of 59 sedentary men and women, one group improved their aerobic fitness by walking, while the other stretched and toned. “We found increases in brain volume and gray matter in those who walked, but not in those who stretched,” says lead researcher Arthur F. Kramer, PhD, a professor of psychology at the University of Illinois at Urbana-Champaign. “People who did the aerobic workout also showed improved cognitive function, especially in the areas of memory, decision making, and switching from one task to another.”
But reaping brain benefits doesn’t require training for a marathon. Gage saw improvement in mice that spent two hours a day on the running wheel; for us, he explains, that translates into walking. Kramer advocates “brisk walking three times a week, for up to an hour each time.” Gomez-Pinilla suggests an activity like swimming or running, 30 minutes a day, five days a week. Whatever it is you choose to do, the point is: Get moving.
Thanks to a fitness routine that includes weights and cardio four times a week, Rachel Capaldi has lost 30 pounds and feels reenergized. “I’m relaxed and alert,” she says. “I think faster, and I retain information a lot better. My GPA has gone from a 3.2 to a 3.8.”
“Exercise enables us to think more clearly, make decisions more quickly and accurately, and retain memory better than we otherwise would,” says Kramer. “It’s never too late to start.”
My Mini Vacation Trick
“If I want to see a stressed-out woman, all I need to do is look in the mirror. I have two kids under the age of 2. A husband. A dog. A full-time job. Like the 51 percent of women who said in a recent survey that they’re concerned about the amount of stress in their lives, I feel consumed with chores and errands. No wonder we’re frazzled.
“I discovered the secret to stopping the insanity from my husband. At home he’s always so calm and relaxed. He throws on his sweats, plays with the kids, and just enjoys some downtime. The man is onto something. Every now and then you need to take a break. Give yourself a mini vacation from all the little stresses in your life. No, it’s not quite like having sand between your toes or a piña colada in your hand, but boy does it feel good!
— Susan Koeppen, consumer correspondent for CBS News’ The Early Show and a FITNESS contributor