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. .-.-:-:-:-:-:-:-:-:-:-:-.-.-. . .. -:-::::-:-:-:-:-:-:-:-:-::::::::-:-.- ::--- :::-: ~ .-:-:-:-:-:-:-:-:-:-----------:-:-:-:-:-:-:-:-:-:-: . -:-:-. .-::-:-::::: ::-:: :'::-:-::-. -:-:::::::::::::::-:- :::-. I-:- : ~ - :-: ~ - :-:: :.: :.! - - :.: .. i.!-~- . -:. - : -:- .. a-.:. ~ - .. ::- -.-.- .- ' 2-:--:-.- -:-:--:-- ::: Gentler Differences in Health Both likenesses and differences go back to the very moment of conception. Gender begins in an individual's genes. Of the 46 chromosomes that compose the human genome, 45 distinguish not at all between males and females. The crucial forty-sixth alone deter- mines genetic gender at the moment that sperm meets egg. In all cells but the type involved in fertilization, chromosomes come two by two, forming a total of 23 pairs. At conception, each parent bestows on each offspring one randomly chosen member of each of his or her pairs. All but one of these pairs consist of two chromosomes equal in size. The gender-picking set, however, comes in two versions, the full- sized X and the much smaller Y. Females possess two Xs, so a mother can only pass along one of that type. Males, however, possess both an X and a Y. so a father can transmit either one. Each of the father's sperm and each of the mother's eggs, alone of all the cells in the body, contain only 23 individual chromosomes, one from each pair. The process that creates these special cells assigns each individual egg or sperm its particular complement of chromosomes appar- ently at random. The sperm, in their multitudes, race toward the solitary ovum, each bearing a gender-determining X or Y. One and only one sperm cell penetrates the large, slow-moving prize. At that instant, as the two half-sets of chromosomes combine, the newly formed person-to-be 15

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I N H E R O WN R ~ G HT comes into possession of the full genetic complement that will last and shape a lifetime. An embryo that happens to receive the paternal Y will almost certainly emerge nine months later to cries of"It's a boy!" One getting two Xs will proceed to develop as a girl. As a girl, not into a girl. In Homo sapiens, as in all mammals, the female is the so-called "default" gender; every embryonic human would develop the body of a female if nothing intervened. Early in its growth, each embryo develops two sets of rudimentary ducts, the basic where- withal needed to grow into a mature member of either sex. The mullerian duct stands poised to become uterus and fallopian tubes, the Wolff~an, the male reproductive organs. In addition, the embryo's equipment includes as-yet undifferentiated gonadal cells, forerunner of its future ovaries or testes. If specific male-making events do not happen early enough in the pregnancy to derail the process, the mullerian duct grows into full-fledged female organs and the boolean duct withers. The thing that permits- indeed, forces masculine development arrives on the Y chromosome. At the proper developmental moment, before a mother-to-be may even know for sure she is pregnant, the future male's gonads receive a signal to grow into testes. Without this signal, the gonads mature into ovaries. The Y chromosome thus throws a binary switch that selects between two gender possibilities. But this initial differentiation constitutes only the first, though absolutely crucial, step in the multistage procedure that will result in a male. In engineering parlance, this first step starts a "cascade" of events that broaden its effect far beyond its initial power. In the second step the newly functioning testes begin produc ing a substance that directs the mullerian duct to degenerate, erasing the embryo's female potential. Later on, testicular hormones called androgens (literally, "male makers") prod the Wolff~an tract to mature, setting out the masculine organs. Unless both these signals reach their destinations, the turn toward masculinity simply does not occur, or occurs incom- pletely. In such cases, female development proceeds. The rare XY indi- vidual whose cells are genetically unable to respond to certain androgens, for example, has the outer appearance, but not the full inner equipment, of a female. Further along in fetal development, androgens signal the brain to prepare for the time, lying more than a decade in the future, when it 16

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C HA P T E R 2 Cal Gender Differences in Health will act in a mature male-like way. Specifically, this step lays the ground- work for a masculine rather than a feminine puberty. It assures that the young brain will fail to produce the hormonal feedback loop that orches- trates the menstrual cycle. With the onset of puberty, additional hormones will signal the development of such secondary masculine traits as body hair, the voice-lowering enlargement of the larynx, and the broad shoul- ders that produce the male rather than the female silhouette. Within these two distinctly shaped frames, however, many of the infinitely complex mechanisms that compose the human body none- theless function quite similarly. The doings of chromosome number 46 have riveted society's attention since time immemorial, but the other 45 clearly exert far greater combined influence. Males and females of the human species share an over~vLelming number of features of anatomy, physiology, and behavior. Only the organs specifically related to repro- duction belong exclusively to one gender or the other. Even secondary sexual characteristics like the female breast and the deeper male voice derive from structures shared by both genders. These two similar bodies, however, still contain sufficient dis- crepancies, or perhaps undergo sufficiently different stresses during their lifetimes, to produce quite noticeably discrepant patterns of illness and health. Some differences arise from reasons so obvious as to be trivial; men cannot suffer preeclampsia of pregnancy nor women contract prostate cancer (although men can and do develop breast cancer). More serious and substantive variations different rates of mental disorder, different ages for heart disease have spurred spirited debate but as yet inadequate research. Anecdotal evidence from both the bedside and the laboratory suggests still further differences as yet suspected but not definitely proven. M4 TTERS OF LIFE AND DEATH The simplest and most straightforward difference is also the most mysterious. Throughout the developed world, wherever women no longer routinely die in childbirth, women on average live longer than men 6.9 years longer in the United States, for example.) Demographers noticed this longevity gap as long ago as 1900, decades before cigarette smoking, once a predominantly male habit, and a major killer of Ameri 17

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I N H E R O WN R ~ G HT can men for at least 40 years, became commonplace. "It appears to be present in all races and under all social conditions," notes Maureen M. Henderson, M.D., D.P.H., professor of epidemiology and medicine at the University of Washington and a leading expert in the epidemiology of diseased Nor do the factors favoring females seem to cluster in any particular stretch of the human life span. "Women's survival advantage exists in infancy and childhood, that is, before puberty and circulating levels of reproductive hormones," says Henderson.3 "At all ages, from conception on," adds Leon E. Rosenberg, M.D., president of the Bristol- Myers Squibb Pharmaceutical Research Institute, relatively more males than females die. "Approximately 125 male fetuses are conceived for ev- ery 100 female fetuses, but 27 percent more boys than girls die in the first year of life. By the time they have lived 100 years, women outnumber men five to one."4 Differentials as marked as these powerfully shape de mographics. Women constitute almost 60% of Americans over 65 and 75% of those over 85 the fastest-growing segment of our population.5 Exactly what kills the genders at such different rates remains much less obvious. Clearly, both biological and behavioral factors come into play. "One very critical biological component," Henderson suggests, is females' "more responsive immune system." Testing of the hepatitis B vaccine confirmed clinicians' long-standing suspicion that women fight off infectious invaders better than men. "At every age, exposure for expo- sure, females have better antibody responses."6 Whether facing bacteria in hospital nurseries, the viruses coughed and sneezed among infants and children, or even, as some suggest, the viruses associated with certain cancers, female immune systems appear to put up stiffer resistance. But, Henderson acknowledges, "other components of this bet- ter female survival have yet to be thoroughly explored and described." Women's recent mass exodus from home to the workplace, for example, has produced no noticeable effect on their death rates, despite predictions that job stresses would push them closer to the pattern of male mortality. But, one factor, she notes, "is slowly and surely lowering women's sur- vival rates closer to men's" the recent, sharp increase in females smoking cigarettes, particularly among teenage girls and young women. "On bal- ance, however, women are currently holding onto their survival advan 18

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C HA P T E R 2 Cal Gender Differences in Health tage."7 That fact suggests to some that, given the damage from increased smoking, joining the paid workforce might somehow help rather than harm women's health. But that mystery only deepens another one. Women, Rosenberg puzzles, "are sicker, but live longer." They spend more days confined to bed, take more time off from work, go to the hospital more, and see doctors more often. No one knows why, but social reasons strike many as likely. How people perceive symptoms, what they think they should do about them, and where they stand in the social structure all influence whether they consider themselves sick. Denying illness, Rosenberg notes, is "culturally approved" behavior that discourages men from seeing a doctor in the first place or complying with instructions when they do.8 Cultural factors aside, does the first mystery, women s longer survival, even more paradoxically suggest an answer to the second, their higher disease rate? By living longer, many more of them reach the age range most afflicted by disease. Fewer men make it into old age, so the select number who do may have enjoyed some lifelong advantage in resisting disease. "Men over 75 are a particularly robust group if they manage to survive their cohort, and represent biologically a different group of people than their feminine counterparts," suggests Dr. Bertram Cohler, professor of psychology at the University of Chicago.9 This smaller and presumably more exclusive group has already lost many young and middle- aged members to some of the very diseases that afflict elderly women. Coronary heart disease, for example, begins taking its toll of males a decade before it attacks females; myocardial infarction strikes men fully two decades earlier than women.~ Still, when heart disease finally does attack women, it exacts heavy losses. Women die more often than men do from infarctions and surgeries like bypasses and angioplasties. Does something inherent in women's physiology or anatomy smaller, more easily blocked blood ves- sels, for example account for the difference or discrepancies in diagnosis and treatment? Both possibilities have expert support. Heart conditions often present somewhat differently in women than in men, who, because they were long considered the likeliest victims, have shaped the disease's predominant image. Womens' chest complaints may get more cursory 19

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I N H E R O WN R ~ G HT scrutiny, some believe. Indeed, Nanette K. Wenger, M.D., professor of medicine and cardiology at Emory University Medical School, expresses "concern that later diagnosis and less attention to the symptoms" mean that women often miss getting attention during the disease's more treat- able early stages and thus need more emergency surgery in the more dangerous late ones. For "both genders and at all ages Such an operation] carries a higher risk of mortality" than one conducted on a nonemergency basis. The more-selective-male-cohort theory also fails to satisfy some observers. Henderson, for example, sees older women's higher rate of reported disease as simply that, a higher rate of reporting. An ailment swells disease statistics only if and when it comes to a professional's atten- tion. "Women don't suffer from unique conditions"; she notes, "they just report more of the same conditions reported by men." Do they really get sicker more often or do they simply seek care more often when they do? Existing figures, obviously, cannot give the answer. "Throughout their reproductive and later lives," Henderson continues, underlining Rosenberg's point, "women go to the doctor's office more often than men," a habit that can grow in the early years from needing the most effective forms of birth control, available only by pre- scription, and in the later ones from seeking annual Pap smears. Once in the doctor's office, a woman usually answers questions about her general health, and may even fill out a checklist, perhaps prompting her to re- member or recognize symptoms that in themselves would not merit a special call or visit. When healthy men filled out similar lists in one study, Henderson notes, more of them indicated complaints than a comparable group of women. And, she further wonders, might women's more fre- quent contact with health professionals "itself lead to treatments whose existence, consequences, and side effects are then reported as symp- toms" t?] i3 This possibility certainly exists because elderly women annually consume one-fifth more medication than men an average of 5.7 pre- scriptions a year, plus 3.2 different types of over-the-counter remedies. One of every four women over 65 uses 21 different medications annually; only one older man in five uses that many.~4 With overmedication and 20

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C HA P T E R 2 Cal Gender Dfferences in Health drug interactions a recognized cause of symptoms in seniors, women are obviously at somewhat greater risk. The conditions that men and women hope to counter with all these drugs differ by gender as well. Three times as many women as men develop rheumatoid arthritis possibly a manifestation of that extraactive immune system mistakenly turning on one's own tissues. Men suffer more hearing loss, possibly because they have been exposed to more industrial noise. Osteoporosis, which thins the bones and causes painful and dis- abling fractures, strikes vastly more often in women, afflicting 73% of those between 65 and 69 and 89% of those over 75.~5 An American woman faces a risk of life-shortening hip fracture three times greater than a man's and as great 15% during her lifetime as her combined total risk of breast, uterine, and ovarian cancer or a man's lifetime risk of prostate cancer. Half of hip fracture victims never walk again, many falling prey to such complications of immobility as pressure sores, urinary infections, heart arrhythmias, and pneumonia. Overall, hip fractures reduce expected survival by 5 to 20%.~6 So great, in fact, is women's burden of illness and disability in old age that they confront the "horrible travesty" of"not so much living longer, but taking longer to die," in Henderson's words. The grim reali- ties of disease, disability, and resulting loss of independence whittle "their extra seven years of life expectancy . . . down to three good years and four bad."~7 Men who survive to old age spend a greater proportion of their remaining years free of disability. A man still living independently at 70, for example, can look forward, on average, to another 11.4 years, all but 18% of them still independent. But at 70 an independent woman stands to spend 29% of her remaining 15.4 years in a state of dependency. This gives her only 1.6 more independent years than a man but 2.4 more dependent years. Between 1970 and 1987, women's life expectancy rose 3.6 years, but 3.3 of those years entail some limitation on activities. Men, on the other hand, gained only 2.8 years of life expectancy, but two-thirds of it without limitations.~9 But since women's greater disease rate persists throughout the life span, age alone cannot explain it. When investigators seek specific diseases to account for the excess, "some of the differences in reported 21

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I N H E R O WN R ~ G HT rates of acute infectious conditions during early adult life are logical," Henderson notes, given women's closer contact with youngsters carrying home infections from school and day care and their greater responsibility for all family members who take sick. Probably reflecting a drop in home nursing duties as children mature, "men's and women's reported rates of acute infections get much more alike as they get older."20 The same younger women, of an age to be caring for infected small children, are also at the age of highest risk for autoimmune diseases. Might not that more responsive immune system, rallied by the more frequent need to fight infections, sometimes go awry from overenthusiasm? Though these ailments alone do not occur often enough to explain the genders' different illness rates, this is only one of the many questions that await further research. MIND AND MATTER More than immune responses and rates of physical illness dis- tinguish male and female health. The realm of mental health involves discrepancies as large or larger. Overall, mental disorders affect about the same proportion of each sex according to the Epidemiological Catch- ment Area study of the National Institute of Mental Health, a survey of 18,000 American adults living in five communities but in strikingly dis- parate patterns.21 A woman is a third again as likely as a man to suffer obsessive- compulsive and bipolar disorders (manic-depression) at some time in her life, one-half again as likely to develop schizophrenia, and twice as likely to suffer phobias (see Table 2-1~. She also runs more than twice his risk of panic disorder, major depression, and dysthymia (chronic depression), and seven times his risk of somatization disorder, which involves various bodily symptoms. He, meanwhile, has almost twice the chance she does of abus- ing drugs, and about five times her chance of abusing alcohol or develop- ing antisocial personality disorder.22 Whether gender differences in rates of substance abuse are truly as large as the statistics suggest or whether the discrepancies represent women's hesitancy about coming forward for treatment remains unclear, however. Drunkenness has traditionally carried a greater stigma for fe 22

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C HA P T E R 2 Cry Gender Differences in Health TABLE 2-1 Mental and Addictive Disorders in Women and Men Male Lifetime Female Lifetime Odds Disorder Rate per 100 Rate per 100 Ratio Somatization 0.0002 0.4 7.34 Major depression 2.7 5.7 2.41 Panic disorder 0.8 1.8 2.31 Dysthymia 1.9 3.9 2.06 Phobias 9.5 18.3 1.98 Schizophrenia 1.0 1.6 1.48 Obsessive-compulsive disorder 1.8 2.4 1.33 Bipolar disorder 0.6 0.8 1.29 Drug abuse 6.2 3.7 0.64 Antisocial personality 3.7 0.8 0.18 Alcohol abuse 21.2 4.3 0.15 NOTE: Odds ratios are adjusted for age and socioeconomic status. SOURCE: Institute of Medicine, Asssessing Future Research Needs: Mental and Addictive Disorders in Women (SummaryJ, 1991. males than for males. For him, it can indicate toughness, a macho, devil- may-care attitude up to a point, at least. For her, it often still carries an implication of sexual promiscuity, of "easiness," of generally not being a "good" woman.23 Overall, males tend to shove their mental distress outside of themselves to "externalize" it, in technical terminology through "act- ing out" disorders that use violence, crime, chemicals, or some other generally risky behavior to transform feeling into behavior. Females tend to pull their anguish into themselves to "internalize" it in abnormal states of anxiety or mood.24 Depression, which in its various forms strikes about 10% of women during their lifetimes but fewer than 5% of men, in many ways typifies this pattern of difference. After a first episode of major depression, a disabling, even life-threatening disease, persons of both gen- ders run about the same risk of suffering a second. But, "in study after study, we find that women are two to three times as likely as men" to have that crucial first attack, reports Ellen Frank, Ph.D., professor of psy- chology and psychiatry at the University of Pittsburgh. This trend is ap 23

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I N H E R O WN R ~ G HT parent not only in Western countries, but also in 10 nations as diverse as Taiwan and Lebanon, where studies have "found women at least twice as likely to have had one episode of major depression in their lifetime," a ratio that remains remarkably "constant over time."25 Opinions vary about what causes these differing rates. Is it some sort of statistical quirk, what statisticians call an "artifact"? Are women more willing to admit that they feel depressed? Could the criteria psychiatrists use to assess depression somehow distort their perceptions? Are there genetic differences? Hormonal differences? Does it have to do with the social statuses women occupy and the social roles they play? Some recent, important advances in knowledge about depres sion suggest possibilities. Frank notes one of the most significant: "We now understand that children become depressed," an idea formerly con- sidered "extremely controversial."26 We also know that the rates of child- hood depression show a revealing anomaly: "Prior to age 10," Frank says, "there are virtually no differences between males and females, and in some studies we actually see an excess of depression in boys prior to age 10. But at age 10, rates for girls take off relative to boys, and they never come back again."27 For the average girl, that age or the years immediately follow- ing represent the gateway to puberty, the time when she exchanges her asexual child's body for the ripening form of a nubile young woman, the era when her emotions must respond for the first time to unknown, and until then unknowable, issues and pressures. Could the onset of the repro- ductive cycle, with its unaccustomed flood of reproductive hormones, at least partially account for girls' rocketing rates of depression? Numerous authors have suggested links between male-female hormonal differences, which become pronounced at puberty, and various other behavioral dif ferences between the genders. A substantial body of research, for example, links androgens to aggression in a variety of animals, although Donald Pfaff, M.D., professor of neurobiology and behavior at Rockefeller Uni- versity, notes that "the occasions for the aggression and the target for the aggression might be different between species." Couldn't reproductive hormones influence behaviors as well? Pfaff counsels caution in drawing analogies between humans and other animals; "the linkage of hormone- sensitive forebrain circuits" varies among species "in form and magnitude" 24

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C HA P T E R 2 Cal Gender Differences in Health and so, therefore, does hormonal impact on behavior. He finds the con- nection "much less impressive in human beings than it is in many lower mammals." As neurological gender differences get farther from "basic reproductive physiology," they "become smaller and their biological sig- nificance is sometimes quite obscure."28 Frank is also among those who agree that hormonal changes alone do not suffice to explain gender differences in mental disorders. She suggests another, often overlooked, possibility. A significant prepubertal change, and one long "assumed to be driven by social factors," is that around age 10 or 11 children start staying up later and later. But one study found that "biological factors accounted for all the difference" between older and younger children's bedtimes. Those farther along in puberty, regardless of their chronological age, went to bed the latest. When adult volunteers of both genders, isolated in a bunker from any outside cues as to the time of day, have the chance to schedule their own sleep, women will slumber "on average an hour and a half more for every sleep-wake cycle" that corresponds roughly to a 24-hour day.29 Girls, for some as yet unknown reason, thus may well need more sleep than boys. Combining this demand with a later bedtime and the fact that the school day starts at the same early hour regardless of a student's gender could easily produce chronically tired girls "working on an hour and a half sleep deficit" not suffered by boys. "I would argue," Frank concludes, "that this is setting up a kind of fragility in the circadian rhythm" that may partially explain why many more girls than boys of this age become depressed.30 But as important a role as physical changes may play during this tumultuous period, girls must deal with powerful social changes as well. "Pubertal and endocrine changes can't be considered in isolation from the social context in which they occur," Frank insists.3i And one of the starkest social differences dividing the genders is also among the most disturbing. "One of the things we know is that girls are at least twice as vulnerable to childhood sexual abuse as boys," she continues. "In four studies done in quite large samples, we see that rates are almost always at least twice as high for girls as for boys." And other work has decisively established "a direct relationship between childhood sexual abuse and rates of major depression."32 25

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I N H E R O WN R ~ G HT But even if the trauma of sexual abuse does not touch a girl, the "social context" of her puberty and adolescence still differs drastically from a boy's. The change from innocent child to attractive sexual object may come quickly, even abruptly, unlike the more gradual changes in physique and social expectations that typically happen to boys. New and troubling uncertainties about her appearance and sexuality increasingly cloud a girl's long-accustomed self-image and social role as she begins to attract an entirely new type of masculine attention. She suffers "a greater discontinuity" than does a boy in "the transition from childhood into adolescence," notes~ohn ]. Conger, Ph.D., of the University of Colorado Department of Psychiatry. For boys, their role as maturing adolescents and their road toward manhood, their physical development and their aca- demic and vocational progress, all represent "a continuation or heighten- ing of existing trends." Adolescent girls, however, "are more likely to receive mixed messages than boys, whether about sexuality, appropriate sex roles, or vocational aspirations."33 So sudden and starkly visible a break with the past puts many girls under tremendous stress. "The young person who . . . finds a reasonable degree of continuity between the competencies, behaviors and values expected of her or him during middle childhood and those expected during puberty and adolescence will also encounter less difficulty in making the adolescent transition," Conger says. "Societies, subcultures and individual families vary widely in this respect."34 American society appears rather hard on girls moving into ado lescence; the stage constitutes the main exception to the pattern we have observed of greater feminine resilience across the life span. From birth through age 10, boys appear more "vulnerable to both physical and psy- chosocial stressors" than girls, according to an IOM study of mental disor- ders.35 The second decade of life reverses those odds, with girls now showing heightened vulnerability to a host of bodily and psychological ills. By early adulthood, the balance swings back again, with men once more the more vulnerable sex. ADDICTIONS A disturbing trend toward increasing and increasingly early 26

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C HA P T E R 2 Cal Gender Differences in Health use of tobacco, alcohol, and illicit drugs among young women highlights their greater susceptibility to emotional ills during adolescence. Depres- sion or anxiety often afflicts girls who resort to mind-altering substances; whether the contraband chemicals cause the mood disorders or represent a disturbed youngster's attempt at self-medication remains controversial among experts. Male substance abusers much more often suffer antisocial personality disorder than disorders of mood.36 A girl who responds to the stresses or biochemical changes of adolescence with depression thus runs an increased risk of becoming a substance abuser and even an addict. Smoking, long a mainly masculine addiction, now poses a par- ticular threat to emotionally vulnerable young women. For many years, and in many countries, a traditional gender gap shaped tobacco use. In Indonesia in 1990, for example, 75% of men smoked, but only 15% of women; in Japan, 70% and 15%, respectively.37 A similar pattern held in the United States until a generation or so ago. In 1966, for example, only 30% of girls and young women had ever lit up, as compared to 80% of young men. "Before 1960, unquestionably, no matter how you cut the data, more men than women used tobacco products," according to Neil E. Grunberg, Ph.D., professor of psychology at the Uniformed Services University School of Medicine. The pattern held for cigarettes and even more strikingly for cigars, pipes, and chewing tobacco. But then the pat- tern began to change; by 1980 more women than men were experiment- ing with tobacco, and by 1990 more teenage girls smoked than boys.38 Today's smokers, Grunberg observes, are "stereotypically young women, generally middle class to upper middle class, . . . and . . . blue collar men."39 Though the great rise in female smoking coincided with ep- och-making changes in women's social roles, "it's not just cultural," Grunberg believes. Males and females do not metabolize nicotine identi- cally; evidence suggests that their differing reactions, along with divergent body weight and other factors that affect the molecules' distribution in the body, create different levels of sensitivity in how the two genders react to and metabolize nicotine. Grunberg's own laboratory studied nicotine in rats. "We discovered, to our surprise, that nicotine had a greater effect, dose for dose, in females than in males on body weight and eating behav- ior, completely consistent with human self reports."40 27

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I N H E R O WN R ~ G HT "Everything about the smoking picture is bleak," Henderson laments. "More school girls than school boys are regular smokers by the time they reach tenth grade," and the rise among young women has been particularly sharp.41 "Cigarette smoking is the habit most likely to drasti- cally change women's overall health status. Unless women stop taking up this habit, lung cancer rates will reach epidemic proportion during the next 20 to 30 years. But lung cancer will be only one of the health consequences."42 Women smokers can expect to bear more low-birth weight babies and suffer more heart and lung disease, osteoporosis, and other cancer as well. Alcohol presents a similarly dismal outlook among young women. More adolescent males than females drink, but the percentage of girls among the very youngest persons drinking to getting drunk chil- dren between 10 and 15 is rising fast.43 As with cigarettes, this increase portends grim possibilities because alcohol can both devastate a develop- ing fetus and disproportionately injure a female drinker. "We've only recently begun to discover some of the important differences in the im- pact of drugs and alcohol on males and females," says Frederick K. Goodwin, Ph.D., former administrator of the Alcohol, Drug Abuse and Mental Health Administration. These "important differences" range from the "straightforward" men's greater ability to metabolize alcohol with stomach enzymes and their resulting lower risk of damage to liver, brain, and other organs to the "subtle" interactions with the "highly com plex reproductive system in females" as opposed to the "relatively simple reproductive system in males."44 Recent research shows that women's stomachs contain less al cohol debydrogenase, the enzyme that metabolizes alcohol before it enters the bloodstream. For any amount a man and a woman drink, more alco- hol reaches her blood. For any amount drunk, she runs a higher risk of alcoholism and liver damage. In women, alcoholism takes a "telescoped course," says Sheila Blume, M.D., medical director of Alcohol, Chemical Dependency, and Compulsive Gambling Programs at South Oaks Hospi- tal, Amityville, New York. "They start later but once they start it moves faster." Females treated for alcoholism also have a higher mortality rate than males.45 Whether other drugs of abuse affect the genders differently 28

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C HA P T E R 2 Cat Gender Differences in Health remains unclear. "Drug metabolism differences by gender have been poorly studied," found an IOM study on women and health research; from puberty on, though, male metabolic rates outpace those offemales.46 That higher metabolism also helps men lose weight more easily, a physi ological fact, the same study found, that combines with our "cultural emphasis on thinness and beauty in women to translate in a higher preva- lence of eating disorders, such as anorexia nervosa and bulimia," condi- tions multiplying in young women but almost nonexistent in men.47 BODIES OF EVIDENCE In her struggle for fashionable emaciation, today's female dieter battles not only an increasingly unrealistic standard of beauty but also the inborn recalcitrance of her own body. "On average, the percent body fat of women is approximately 10 points higher than for men," notes Kirk J. Cureton, Ph.D., professor of exercise science at the University of Georgia and an expert on body composition. Thus the gender obsessed with thin- ness is also the one that finds it harder to achieve. This difference consti- tutes more than a cruel genetic joke. Female fat acts decisively in both the economy of reproduction and the physiology of bone. Too little means amenorrhea and premature bone loss. Besides being fatter than men, women are also less lean. "In adulthood," writes Stanley M. Garn, Ph.D., professor of anthropology and nutrition at the University of Michigan, "the man generally has a larger lean body weight by a ratio of 3 2."48 TL;~ ~ 1~ 1 1115 Brcaccr IllUbUl~ 111~S means that a man is both stronger than a woman of the same size and weight and to the dismay of female dieters needs more calories as well. "At all ages, from the first trimester through the tenth de- cade," Garn notes, men on average are taller and weigh more than fe- males. "Even during childhood," when boys and girls measure most alike, "the chromosomal XY For male person] is considerably larger than the chromosomal XX For female person] of the same physiologic (or skeletal) age."49 (See Table 2-2.) That's because girls mature sooner than boys and are therefore physiologically "older" at the same chronological age. Men also continue growing into their early twenties, while women stop in their early to mid-teens. Thus, men end up 6 to 7% taller than women 29

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I N H E R O WN R ~ G HT TABLE 2-2 Correspondences Between Male and Female Percentiles for Size and Body Composition in 30- to 39-Year-Old Tecumseh, Michigan, Men and Women Male Centiles Corresponding to: Measure Womens' 50th Percentile Women's 85th Percentile Stature 2.0 13.1 Weight 7.0 40.6 Fat weight 45.0 88.5 Lean body weight 2.3 18.1 Bone area 3.4 10.4 Cortical area 2.0 14.0 Medullary area 34.4 48.0 Skeletal weight 0.8 8.4 NOTE: This table should be read in the following manner: The 50th percentile for stature in women corresponds to the 2nd percentile in men. The 85th percentile for stature in women corresponds to the 13th percentile for men. Note that the sexes are almost alike in fat weight and skeletal weight. SOURCE: Institute of Medicine, Body Composition and Physical Performance: Applications for the Military Services, 1992, page 211. "across the socioeconomic range and in different genetic populations," with the additional height concentrated in longer arms and legs a fact important to designers of driver's seats, machinery, control panels, and the like.50 Men's skeletons, besides being longer on average, also weigh more by a ratio of 4:3 and contain more calcium than women's. Women have "smaller skeletons, less bone tissue, smaller bone widths and smaller cortical score] bone area" than men.5i One might expect them, Garn suggests, to have more fractures. But until their mid- forties, female skeletons actually prove tougher. The tendency in men toward riskier driving and more dangerous jobs and recreational activities may partially explain this paradox. Both genders lose bone tissue as they age, but for some reason menopause speeds up the process. In her lifetime a woman may lose as much as one-third of the bone she started with in her limb shafts and as much as one-half of her original supply in the shaft 30

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C HA P T E R 2 cay Gender Differences in Health ends, the spine, the pelvis, and other flat bones. A man, who had more calcium to begin with, over his lifetime loses one-third less of his larger original endowment.52 And further worsening older women's chances of avoiding fractures, most women, after a lifetime of exercising less than men, become more sedentary with age and miss out on the weight- bearing exercise known to help preserve bone.53 IN CONCLUSION Like much else about the nature of the genders today, their health differences are, as Churchill said of Russia, "a riddle wrapped in a mystery inside an enigma." Layer upon layer of incomplete insight and spotty data cloud our understanding of how and why women's health experience differs from men's. What's more, we know too little about how the genders' differing endowments set up their characteristic vulner- abilities. Nor have we yet come close to understanding how various treat- ments and medications differentially affect those distinct physiologies and physiques. And our grasp of the social forces and life experiences at play remains rudimentary. Women's health and the factors that affect it have only begun to attract wide scientific interest. Ten or twenty years hence the writer of a chapter comparable to this one should fill many more pages and need many fewer "not yets" and "unknowns" and "controversials." The true age of discovery has just begun. NOTES 1. Disability in America: Toward a National Agendafor Prevention, 62. 89. 165. 2. IOM 1992 Annual Meeting, 8. 3. Ibid., 8. 4. Ibid., 4. 5. Women and Health Research: Ethical and Legal Issues of Including Women in Clinical Trials, Vol. 1, 6. IOM 1992 Annual Meeting, 8-g. 7. Ibid. 8. Ibid., 5. 9. Assessing Future Research Needs: Mental and Addictive Disorders in Women (Transcript), 10. IOM 1992 Annual Meeting, 105. 11. Ibid., 113-4. 12. Ibid., 15. 31

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I N H E R O WN R ~ G HT Ibid., 16. Women and Health Research, Vol. 1, 89. Ibid. The Second 50 Years: Promoting Health and Preventing Disability, 78. IOM 1992 Annual Meeting, 13. Disability in America, 67. Ibid., 62. 13. 14. 15. 16. 17. 18. 19. 20. IOM 1992 Annual Meeting, 14-5. 21. Assessing Future Research Needs: Mental and Addictive Disorders in Women (Summary), 9. Ibid., 9a. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. Assessing Future Research Needs (Transcript), 156. 34. Ibid. 35. Reducing Risks for Mental Disorders, 182. 36. Ibid., 8. 37. Assessing Future Research Needs (Transcript), 47. 38. Ibid., 50. 39. Ibid., 49. 40. Ibid., 50. 41. IOM 1992 Annual Meeting, 17-8. Ibid., 17. 43. Health and Behavior: Frontiersfor Research in the Biobehavioral Sciences, 91. 44. Assessing Future Research Needs (Transcript), 8. 45. Ibid., 219. 46. Women and Health Research, Vol. 1, 86. 47. Ibid., 91. 48. 49. 50. 51. 52. 53. Broadening the Base of Treatmentfor Alcohol Problems, 57. Reducing Risks for Mental Disorders: Frontiersfor Preventive Intervention Research, 85. IOM 1992 Annual Meeting, 119-20. Ibid., 120-1. Ibid., 121. Ibid., 38. Ibid., 124-5. Ibid. Ibid., 122. Ibid., 126. Body Composition and Physical Performance: Applicationsfor the Military Services, 207. Ibid. Ibid. Ibid., 210. The Second 50 Years, 83. Women and Health Research, Vol. 1, 90. 32