The human body’s reaction to stress is a wonderful thing. Often called the fight-or-flight response, it uses hormones to kick your body into overdrive briefly and intensely to deal with potentially life-threatening situations.

This evolutionary adaptation, invaluable when one is fleeing from mammoths or hunting bison, may seem less useful in our modern times.

But the thing is, we still use it -- the stimuli may have changed from prehistoric predators to tough bosses and traffic jams, but the response is the same.

When a person is under life stresses frequently or chronically, the fight-or-flight response stays turned on constantly. It’s like driving with the gas pedal pushed to the floor all of the time -- it’s going to wear out some important parts of the machine prematurely.

How Stress Hurts

The fight-or-flight response triggered by stress releases a series of hormones. Adrenaline causes your heart to pump about three times as much blood per minute as it does when you’re resting, raising blood pressure.

It interacts with the hormone cortisol to cause fat cells to pour fat and glucose into your bloodstream, providing energy for your muscles to help you escape or defeat an external threat.

“All of this makes a lot of evolutionary sense,” says Duke behavioral medicine researcher Redford Williams, MD, an expert on stress. “However, if the situation is not another caveman or a saber-toothed tiger after you -- just a lot of demands and very low control over how to meet those demands in work or in life in general -- this response being elicited day in and day out will damage your heart.”

The Real Deal

Constantly elevated blood pressure (aka hypertension) can cause the lining of the arteries in your heart to develop small tears. The fat that is being released gets turned into cholesterol and enters coronary arteries through the tears.

White blood cells rush to the tiny wounds to repair the damage, but end up mixing with the cholesterol to form atherosclerotic plaque. If the plaque becomes large enough to rupture, a clot forms and closes off the artery. That is what’s known as a heart attack.

Choose the Proper Path

What can we do to reduce chronic stress and its heartbreaking consequences? Coping skills and relaxation/meditation techniques are the keys to managing stress.

The fight-or-flight response is a function of the sympathetic nervous system. Practicing meditation or relaxation techniques engages the parasympathetic nervous system and allows the body to begin to shut down the sympathetic nervous stress response.

Williams cites two studies in Sweden showing a lower death rate among people with heart disease who learn these skills and techniques, and clinical trials in the United States proving that meditation can lower blood pressure. These practices can even reduce how high your blood pressure rises when you are under stress.

Perhaps the most important skill to learn is recognizing what causes you stress, and nipping it in the bud immediately.

Learning to evaluate your thoughts and feelings in stressful situations can help you decide what approach to take: simply remove yourself from the situation, even for just a few minutes; practice deep breathing; go for a brief walk; or enjoy a short chat with a friend, colleague, or loved one. It could be that your distress is a useful signal that you need to do something more active to change the situation that is stressing you.

Defeat Stress with Mind Power

Jessica Wakefield, a counselor at Duke Integrative Medicine and with the Duke Cardiac Rehabilitation program, says that in addition to relaxation, it’s important to learn mindfulness meditation practices because they help you recognize your signs of stress and provide you with much information about how you react to stressors.

If learning meditation practices isn’t for you, here are a few simple tips from Wakefield to engage your relaxation response and begin to shut down stress.

• Deep diaphragmatic breathing (even a few breaths help)
• Participate in hobbies
• Listen to music
• Visualization -- use your imagination to see something relaxing
• Learn to say no -- set limits and don’t stretch yourself thin with too many commitments
• Take mini-breaks -- at work or at home, remove yourself from a stressful situation for a few moments

Learn more about stress-reduction programs offered by Duke Integrative Medicine.

Stress Damages DNA, Too

Duke researcher Robert Lefkowitz, MD, and postdoctoral fellow Makoto Hara, PhD, recently proved how chronic stress damages your DNA, opening the door to cancer and premature aging.

Lefkowitz and Hara showed that chronically elevated adrenaline reduces the levels of a protein that is important for repairing DNA damage and repressing tumors.

This biochemical pathway that operates in cells transmits its signals through a specific type of beta-receptor. Almost all patients being treated for cardiovascular disease take beta-blockers.

Lefkowitz says that it’s a reasonable theory that patients on beta-blockers might be somewhat protected against this type of stress-induced DNA damage. Supporting this hypothesis are studies suggesting lower rates of prostate and lung cancers among patients taking beta-blockers.