Work, finances, kids' schedules, relationship problems, sick parents, your own health issues—there are so many sources of stress in our modern daily lives. When you experience stress, your body releases powerful chemicals and hormones, including one called cortisol, that prepare your body to fight or flee a perceived threat or danger—the "fight or flight" response. "That response creates a biochemical soup that changes the chemistry of our blood," explains Elissa Epel, PhD, associate professor in the department of psychiatry at the University of California, San Francisco.
The fight or flight response is beneficial in the short run; it helps us deal with a variety of dangerous situations. After the threat has been resolved, hormones level off and your body goes back to baseline. But if these high levels of stress chemicals persist—as they often do when someone is living a high-pressure life—they can be harmful. Instead of protecting the body, they can cause damage to molecules and tissues and lead to a weakened immune system, acne and other problems, including increased intra-abdominal fat, the kind that puts the body at risk for stroke, heart disease and high blood pressure. The stress response also triggers higher levels of damaging free radicals, inflammation and, in some cases, even spikes in insulin and glucose levels that make the body seem prediabetic. And all of these, not surprisingly, can speed up the aging process.
Prolonged stress can also be extremely harmful to the brain. Studies have shown that persistent stress can cause depression and anxiety. It can kill brain cells and damage the hippocampus, the area in charge of memory and learning (research suggests stress actually shrinks this portion of the brain). When damaged, the hippocampus cannot create new memories or access stored ones as efficiently. And because the hippocampus is part of the system that signals the body to stop producing cortisol, levels of the stress hormone can remain out of control and continue to harm the body.
The effects of prolonged stress can even be seen on a cellular level. Epel's research has shown that people with high stress levels have shorter telomeres, which we know is indicative of whole-body aging.
Managing current sources of stress is a must, but it's also important to realize that the stress experienced in the past can play a role in your present-day well-being too. Research shows that stressful or traumatic life events that you experienced as a child—for instance, losing a parent—can have a powerful and lasting effect. "Really stressful events from childhood can add a couple years to a person's subjective age; they can make people feel older," says Markus Schafer, a sociology researcher at Purdue University. "On the other hand, when people feel in control of their lives and things are going smoothly, they're better able to maintain a sense of youthfulness."
Whether it's stress from the past or stress in the present that you're battling, it may make it more difficult to fight the physical decline that comes with aging. With my own clients, I've seen those overly affected by stress become overwhelmed and have a hard time living up to their eating and exercise goals. When you're stressed out, a comfy couch and a carton of ice cream become a lot more appealing than getting on a treadmill or having a healthy meal—although both of the latter (especially exercise) are good antidotes for stress. Stress also has a tremendous effect on attitude. It can make you feel negative about yourself and your life; it's hard to appreciate all the good things you have when you're overburdened, tense and pressured. Stress can simply sap all the joy and happiness right out of you.