With stress and the brain at war, the body's a battleground

Pressures override natural defenses against disease, aggravate ailments

Health & Fitness

April 18, 2004|By Jane E. Allen | Jane E. Allen,Los Angeles Times

As a high-level executive for a large computer manufacturer, Dan Bishop was a self-described workaholic who thought he was ably juggling daily demands and corporate pressures. Then he woke up one night with tightness in his chest, barely able to breathe. At first he suspected a heart attack. The tightness quickly passed, but he was frightened enough to see his doctor.

The doctor diagnosed an anxiety attack -- caused by stress -- and told him to "stop being so driven."

"I didn't know what stress was; I didn't think I had stress," said Bishop, now 52, referring to the 1990 diagnosis.

As Bishop found, stress can be insidious. The pressures of daily life -- jobs, relationships, money, raising children and now war and terrorism -- have become such constant companions that many operate with ever- present feelings of pressure, anxiety or burnout.

The stress can become so unflagging that many people have accepted it as a standard part of life. Although we may try to ignore its presence, stress doesn't go away. It just goes to work inside the body.

Prolonged stress contributes to many physical and psychological ills. It overrides natural defenses against viruses that cause AIDS, chickenpox and the common cold; encourages the production of inflammatory hormones that drive heart disease, obesity and diabetes; sparks flare-ups of rheumatoid arthritis and digestive disorders; creates depression and ages the brain.

"Numerous studies show that psychological stress can lead to illness or even death," said Dr. Michael Irwin, director of the Norman Cousins Center for Psychoneuroimmunology at the University of California, Los Angeles' Neuropsychiatric Institute. "How we cope with stress and whether or not we get depressed is crucial for our health."

Unchecked stress sends out complex signals that unleash a cascade of activity throughout the body. When someone is confronted with stress -- whether physical or psychological -- the brain is the first part of the body to respond, reacting in two ways.

In one reaction, a regulatory part of the brain called the hypothalamus sends signals through sympathetic nerves near the spinal cord to the adrenal glands, commanding them to release the stress hormones epinephrine and norepinephrine (also called adrenaline and noradrenaline).

These hormones gird the body for action. They boost heart rate, blood pressure, breathing and blood flow to the muscles and brain, providing an extra surge of energy in times of physical danger. They can also keep athletes, entertainers and others on their toes, keeping them alert and productive when performance counts.

But chronic stress opens the floodgates to epinephrine and norepinephrine, regardless of whether there's a threat, allowing bacteria, viruses or tumors to flourish and making blood more prone to clotting.

The brain's other reaction comes through the pituitary gland, which sends signals through the bloodstream instructing the adrenal glands to release the stress hormone cortisol and other steroids. In the right amounts, cortisol helps the body recharge, enhances disease resistance, fights inflammation and improves memory.

In excess, however, cortisol promotes the accumulation of abdominal fat, suppresses immunity, shrinks brain cells and impairs memory. Over time, cells become less sensitive to the protective effects of cortisol, and inflammation goes unchecked.

Scientists are only now beginning to understand what happens when stress disrupts the delicate interplay between the brain, the endocrine system -- the glands and organs that make and release hormones -- and the immune system, stimulating the release of compounds that cause inflammation. They're also beginning to identify ways to stop this inflammation.

Physical or mental stress can take an enormous and sometimes deadly toll on the heart. It increases blood pressure, narrows blood vessels and causes blood to become stickier and more likely to clot, increasing the likelihood of a heart attack or stroke.

As their understanding of the biochemistry of stress increases, scientists around the country are developing and testing ways to protect the body from its ravages, using yoga, meditation and psychotherapy.

Medications may also prove effective at blocking the destructive effects of stress hormones. In one study, beta blockers, which are typically prescribed for hypertension and heart disease, are being given to HIV patients. The drugs should block the ability of stress hormones to make HIV multiply, researchers say, thus lowering viral loads.

The Los Angeles Times is a Tribune Publishing newspaper.

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