Thomas S. May, M.A.

Medical Writer

Stress Suppresses Body's Defenses: Seniors (Especially) at Risk

Thomas S. May, Medical Writer

Introduction

Pierre Elliott Trudeau was arguably the most popular prime minister in Canadian history. And both before and after his retirement from politics at age 65, he was also remarkably healthy, fit, and energetic for a person his age: He fathered a child at 72, and he regularly participated in vigorous outdoor activities like skiing, canoeing, and scuba diving--well into his 70s.

But in 1998, when he was 79 years old, his youngest son was killed in a skiing accident. From then on, the elder Trudeau's health steadily deteriorated. Within a year, he was diagnosed with prostate cancer, and shortly thereafter he contracted pneumonia. He died on September 28, 2000--less than 2 years after his son's death.

The enormous stress Trudeau suffered when he lost his son probably contributed to the rapid decline in his health and his subsequent death, according to some experts who took part in a recent conference organized by the US National Institutes of Health (NIH).

"Older people are more likely to become ill when they are exposed to stress than are younger adults."

The 2_-day conference, entitled Science of Mind-Body Interactions: An Exploration of Integrative Mechanisms, was co-chaired by Esther M. Sternberg, MD, director of the integrative neural-immune program and chief of the neuroendocrine immunology and behavior section at NIH.

Sternberg says that severe, chronic stress (triggered by the death of a child, for example) may undermine anybody's health but may be especially devastating for seniors. "Older people are more likely to become ill when they are exposed to stress than are younger adults, because there is a natural, biological weakening of the immune system with aging, resulting in a decreased ability to fight infection."

The Mind-Body Connection

Scientists have known for a long time that chronic (long-term) or repeated stress may result in high blood pressure, arteriosclerosis (hardening of the arteries), and various other cardiovascular diseases. During the past few years, however, it has also become clear that stress can suppress the immune system, resulting in increased vulnerability to infections as well as some types of cancer.

In her conference presentation, Sternberg explained how psychological stress can weaken the immune system and contribute to the development of certain diseases. When people are in a threatening or stressful situation, she says, they experience the typical "fight-or-flight response," which involves the release of a series of hormones: A small structure in the brain called the hypothalamus produces corticotropin-releasing hormone (CRH), which stimulates the pituitary gland to release another hormone called ACTH, which in turn causes the adrenal glands to flood the body with hormones called glucocorticoids.

"Glucocorticoids are among the most potent anti-inflammatory chemicals that our bodies make. They turn down the ability of immune cells to create inflammation and fight infections," Sternberg said. "Studies have consistently shown that psychological stress is associated with a variety of illnesses caused by the blunting of the immune response."

Rats infected with herpes and then put in a stressful situation developed signs of the infection that weren't there before.

One such study was done by John Sheridan, PhD, an immunologist at Ohio State University, who presented his findings at the conference. Sheridan and his colleagues exposed some rats infected with the herpes simplex virus (HSV) to a variety of stressful situations. (HSV is the same virus that causes cold sores around the mouth and nose in humans.)

Before the experiment, none of the rats showed any signs of being infected with HSV. However, after a strange rat--an "aggressive intruder"--was introduced into their cage, many of the animals developed herpes lesions. This demonstrated how a stressful situation--like social disruption in this case--may cause an illness.

Increased Risk for Seniors

Despite the fact that their physical reactions to stress tend to be weaker than those of younger individuals, older people are generally more vulnerable to the negative effects of stress. "Older people have weaker immune responses related to normal aging," says Janice Kiecolt-Glaser, PhD, director of the division of health psychology at Ohio State University's Department of Psychiatry.

According to Sternberg, part of that immune system weakening is due to a loss of the nerves that feed the spleen: "The spleen contains lots of immune cells that are important to fight bacteria, and there is a dying-back of those nerves during aging."

Older people have weaker immune systems in part due to a loss of the nerves that feed the spleen, says Esther Sternberg.

Kiecolt-Glaser and her colleagues have done a number of studies on the effects of stress on the aging immune system, and they published a summary of their findings in the February 2001 issue of Current Directions in Psychological Science.

In the article, the authors point out that certain aspects of the immune response decline with age, and there are clear health risks associated with these age-related changes. For example, "although influenza is rarely fatal among healthy younger adults, pneumonia and influenza together constitute the fourth leading cause of death among individuals who are 75 years of age or older."

In one of their studies, Kiecolt-Glaser's group used an influenza vaccine to compare the immune response of individuals who suffered the daily stress of caring for ailing spouses with that of a control group who lacked that stressful feature in their lives. Compared to the controls, the caregivers "exhibited significant deficits in their responses to the influenza vaccine," the investigators found. Moreover, "these differences were magnified in older subjects."

The authors also note that the incidence of cancer increases with age and that a weakened immune system probably contributes to the development of some of these cancers. Furthermore, "cancer treatments such as chemotherapy and radiation enhance the risk of infection, and treatment can also be complicated by infection."

Ways of Coping with Stress

There are a number of things seniors can do to minimize the harmful effects of stress on their body, according to the experts who participated in this year's conference on mind-body interactions. They include

Acknowledge and handle stressors directly and appropriately: Be aware of your own limitations. Try to accept stressful events or situations over which you have no control. Try to reinterpret other stressful situations as challenges.

Seek the aid and emotional support of other people, including family, friends, professionals, and support groups. Older people often tend to stay by themselves when they are stressed or depressed, but this only makes the problem worse.

Maintain good health behaviors: Regular exercise, good nutrition, not smoking, and not drinking too much alcohol can help strengthen your immune system.

Get enough sleep: Most of your body's growth hormone, which helps stimulate your immune defenses, is produced while you sleep.

Learn stress-management techniques like relaxation, self-hypnosis, meditation, or yoga.

Thomas S. May is a medical journalist based in Toronto, Ontario, Canada. He has a master's degree in psychology from Simon Fraser University in Burnaby, British Columbia.

Reviewer: Beth Israel Deaconess Medical Center. Reviewed for medical accuracy by physicians at Beth Israel Deaconess Medical Center (BIDMC), Harvard Medical School. BIDMC does not endorse any products or services advertised on this Web site.

Reprinted from Medscape Health for Consumers.

Home Portfolio Contact