Guest terry jackon1 Posted August 16, 2002 Report Share Posted August 16, 2002 Boston Globe HEALTH SENSE Stressed out? Try a hug By Judy Foreman, 8/13/2002 Do men and women handle stress differently? Or, to put it more provocatively, do women have a built-in hormonal advantage when it comes to dealing with chronic stress? That's the (highly loaded) question at the heart of a fascinating body of research that's got the Internet humming, with enthusiastic e-mails flying from woman to woman. The case for this feminist theory of stress management is circumstantial - built largely on inferences from animal studies and, at some points, leaps of faith. Still, the hypothesis has intuitive appeal, at least to women, so it's worth exploring. For decades, scientists who study the body's physiological response to stress have focused on the ''fight or flight'' model. This view stated that when an animal perceives danger, a number of hormones kick into action. They rev up heart rate and blood pressure, get sugar to the muscles and generally speed things up, the better to fight predators or get out of harm's way, fast. And there is absolutely no question that both males and females have - and need - this system. But this view of stress is both male-biased and incomplete, say a number of researchers, most notably Shelley E. Taylor, a professor of psychology at the University of California at Los Angeles. Taylor's theory, based on more than 200 studies by other people, mostly biologists and psychologists, is that women have a powerful system for fighting stress that's based in part on a hormone called oxytocin. Granted, there's no clear evidence that women on average actually have more oxytocin in their bloodstreams than men. But they do have more of another hormone, estrogen, which does boost the effectiveness of whatever oxytocin is around. Oxytocin, which some dub the ''cuddling'' or social-attachment hormone, is best known as the hormone produced during childbirth and lactation and during orgasm, in both sexes. But it's also secreted during other forms of pleasant touch, such as massage, and has been shown to stimulate bonding in animals, most notably prairie voles and sheep. Even more intriguing, there's evidence from the laboratory of Kerstin Uvnas-Moberg at the Karolinska Institute in Stockholm and elsewhere that oxytocin may act as a genuine ''antistress'' hormone. For instance, the Karolinska group reported in 1998 that daily oxytocin injections, into both male and female rats, decreased blood pressure and the stress hormone, cortisol, and promoted weight gain and wound healing. The group has also shown that injections of oxytocin in rats enhanced sedation and relaxation and reduced fearfulness. To Taylor and her colleagues, the thrust of this evidence suggests that women may be programmed by evolution to deal with stress, not just in the ''male'' way, by fighting aggressors or running away, but also by ''tending and befriending,'' that is, turning to each other for moral support and nurturing the young. In other words, ''there appears to be a counter-regulatory system that may operate more strongly in females than males, that leads to engagement of oxytocin and social contact,'' which in turn may reduce stress, said Taylor, author of the book, ''The Tending Instinct.'' What, then, is really known about oxytocin? Quite a bit. First, it's a tiny molecule of only nine amino acids that is made in a part of the brain called the hypothalamus. It works closely with a related molecule, vasopressin, which is so similar that the two chemicals fit into each other's receptors in the brain, noted Sue Carter, a behavioral neuroendocrinologist at the University of Illinois in Chicago. But, while oxytocin, which acts in tandem with estrogen, often has calming effects, vasopressin, which acts in tandem with the male hormone, testosterone, can act as a stress-response enhancer, by raising blood pressure, among other things. In most species, Carter said, male brains contain more vasopressin than female brains, especially in an area called the amygdala, a fear-processing center. Vasopressin also has been linked to increased aggression and male territoriality. Put another way, oxytocin ''is associated with typically female behaviors, such as childbirth and nurturing the young, whereas vasopressin is associated with male behaviors, such as territorial aggression,'' writes Dr. Norman Rosenthal, clinical professor of psychiatry at Georgetown University, in his new book, ''The Emotional Revolution.'' The most intriguing feature of oxytocin is that it seems to act as both a cause of bonding between animals and a result of it, suggesting that perhaps, through bonding behavior, it can be a stress reducer. For instance, a number of studies have shown that oxytocin promotes bonding in animals - between mothers and babies, and between adults. In prairie voles, Carter's studies show, injections of oxytocin lead to increased bonding. ''Many things stimulate production of oxytocin, including breast stimulation, orgasm or even contact with a friendly companion,'' Carter said. ''All these are known to release oxytocin, which may help damp down the body's reactions to stressful experiences, in men as well as women.'' Several studies, for instance, have suggested that women who nurse their babies have lower anxiety compared to bottle-feeding mothers and that lactating rats exhibit less fear. Beyond oxytocin, there are other chemical clues to differences in the ways in which women and men may handle stress. At Ohio State University, Janice Kiecolt-Glaser, professor of psychiatry at Ohio State University, and her husband, Ronald Glaser, an immunologist, have studied hormonal and immunological responses to stress and found some striking gender differences. In one experiment, the Ohio team asked 90 young, happy, newlywed couples to spend 24 hours, including a night's sleep, in the hospital lab. The researchers placed a catheter in each subject's arm so that blood could be drawn every hour to test for hormone levels and various aspects of immune function. Early in the stay, each couple was asked to spend 30 minutes discussing an area of disagreement. This conflict was recorded on videotapes that were later scored by trained observers, both male and female, for evidence of negative behavior such as hostility, sarcasm, put-downs, etc. The results were stunning: Marital strife was much tougher on women than men. The women showed a faster and more enduring response to hostility, said Kiecolt-Glaser, noting that women's stress hormones (particularly epinephrine, norepinephrine and ACTH) rose more sharply and stayed up longer than those of men. Women also showed a lowering of certain aspects of immune function. In fact, women are more accurate judges of what's going on emotionally. When the outside reviewers rated the videotapes of the couples' interactions, their assessment of hostility and negative behavior correlated with the women's. Women simply experience a bigger stress response to men's sarcasm and hostility than men do to women's. The bottom line? If you feel stressed out, call a friend. If you don't have a friend, make one, or more. And if all else fails, snuggle up with a prairie vole. (what's a prairie vole?) Quote Link to comment Share on other sites More sharing options...
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