‘Fight or Flight’ Hormones Linked to Disease Risks

Stress and depression that send “emergency” hormones flowing into the bloodstream may help cause brittle bones in women, infections and even cancer, researchers say.

A natural “fight or flight” reflex that gave primitive humans the speed and endurance to escape dangers is triggered daily in many modern people, keeping their hormones at constant hyper-readiness, experts say. Even some forms of depression bring on a similar hormonal state.

“In many people these hormones, such as cortisol, turn on and stay on for a long time,” Dr. Philip Gold of the National Institute of Mental Health said Friday. “If you are in danger, cortisol is good for you. . . . But if it becomes unregulated, it can produce disease.”

In extreme cases, this hormonal state destroys appetite, cripples the immune system, shuts down processes that repair tissue, blocks sleep and even breaks down bone, said Gold.

He was among the speakers at a two-day conference of the International Society for Neuroimmunomodulation, a group of experts who study the effects of stress and depression on physical disease.

Gold presented a study of bone density among 26 women, half suffering from depression and half with a normal emotional state. The depressed women had high levels of stress hormones, he said.

Although all the women were age 40, he said, those with depression uniformly “had bone density like that of 70-year-old women. They were clearly at risk of fractures. The magnitude of bone loss was surprising.”

A study at Ohio State University showed that routine marital disagreements can cause the “fight or flight” hormone reaction.

Dr. Janice Kiecolt-Glaser, a psychologist, said a study of 90 newlywed couples showed that marriage arguments were particularly damaging to women.

Blood samples taken during the disagreements showed that women experienced sudden and high levels of stress hormones, just as if they were in a “fight or flight” situation of great danger. The women also had steeper increases than the men and their increases lasted longer.

People with such high levels of stress hormones are at a much greater risk of getting sick, said Dr. Ronald Glaser, an Ohio State virologist and the husband of Kiecolt-Glaser.

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Glaser tested the effects of stress on the immune system by giving hepatitis vaccine shots to 48 students, including 23 medical students with high levels of stress hormones caused by final examinations. When tested a month later, the students who had been under stress developed the least protection against hepatitis.

Glaser said that people with weak immune systems caused by high stress hormone levels also are more likely to become infected with viruses that are linked to cancer.