Gender Gap : Experts Ask Why Women Outlive Men
“Men are extremely fragile,” says biophysicist Estelle Ramey, speaking only slightly tongue-in-cheek. “They should be protected and covered up at night so they don’t die like flies.”
The numbers show she has a point: The gap in life expectancy between the sexes is seven years, advantage to the women. A baby girl born in the United States today can expect to live 78 years, a boy 71 years.
The male of the species begins life with a big edge. At the moment of conception, scientists believe, there are 130 males for every 100 females.
Stronger in Womb
But even in the womb, females are the tougher sex. Only 105 boys are born for every 100 girls, and every passing year alters the balance in favor of women until they overtake men at age 31 and outnumber them by more than 2 to 1 after age 85.
All the big killers--heart attacks, cancer and stroke--strike men harder and earlier than women. So do other causes of death--accidents, murder and suicide.
While the facts are certain, decades of research have left the causes nearly as mysterious as ever. The theories range from evolution to life style:
--Nature demands healthy women to perpetuate the human species. Thus deaths from heart attacks are almost unknown among women of child-bearing years, although both sexes show approximately the same level of cholesterol in the blood. Scientists speculate that female hormones guard against heart disease and strokes.
Women Smoke Less
--Fewer women are smokers. Even among smokers, women smoke less than men, an average of 21 cigarettes a day compared with 33. Consequently, fewer women than men develop lung cancer.
--Women are more likely to see a doctor and to follow instructions for taking medicine. Three-quarters of American women who suffer from high blood pressure have been diagnosed by a physician, compared with less than half the men.
--Fewer women face the pollution and other hazards of the factory. Despite the flood of women into jobs outside the home, only 51% of adult women are in the work force, compared with 71% of men. And women are under-represented in pressure-cooker management jobs, holding just 37% of all executive and administrative positions.
--Women handle stress better when they have to. When a woman dies, her surviving husband has a good chance of becoming seriously ill within a year. When a man dies, by contrast, his wife is much less likely to get sick.
“The honest answer is, I don’t know why women live longer,” said Dr. Edward Schneider, dean of the Andrus Gerontology Center at the University of Southern California. “If you talk to a geneticist, the answer will be it’s 90% genetics. An endocrinologist will tell you it’s 90% hormones, and a psychologist will say it’s stress.”
There may be some truth to all the theories, whether they are based on biology or behavior.
“You can’t separate the two,” said Ramey, a professor of physiology and biophysics at Georgetown University in Washington. “Women have the biological aces, and they are socially conditioned to take better care, to pay attention to eating, drinking and sleeping, to go to the doctor when they’ve got a symptom.”
Until recent generations, widespread infectious diseases suppressed the longevity gap. In 1900, life expectancy was just 46 years for men and 48 for women.
Advantage Expresses Itself
Antibiotics, improved nutrition and modern sanitation systems have curbed infectious diseases and given the “biological advantage of women a chance to express itself,” said James Fozard, associate director of the Gerontology Research Center in Baltimore, a unit of the National Institute on Aging.
The advantage is not unique to Americans. Dr. Alvar Svanborg, who is studying older people in Sweden, says women live longer than men the world over. Nor is it peculiar to humans. In virtually every species of mammal, the female typically outlives the male.
Some scientists wonder if women’s longevity is related to the very factor that determines their sex. Each cell in a woman’s body has two X chromosomes; men’s cells, by contrast, have one X chromosome and one Y chromosome. Chromosomes are the tiny bodies in the nucleus of each cell that contain the carriers of heredity called genes.
Considers Chromosomes
Perhaps, some scientists have speculated, the extra X chromosome in women provides a measure of safety, a chance to make right what is wrong on the other X chromosome. As evidence, Schneider noted that women are typically the carriers and men the victims of certain diseases, such as hemophilia. Queen Victoria of England apparently was a carrier of hemophilia, which struck her son Leopold, the duke of Albany, and her great-grandson Alexis, the son of the last Russian czar.
But this genetic explanation is very tentative. A more compelling biological case can be made for the salutary effects of estrogen and progesterone, the hormones produced in abundance by the female body up to the age of menopause.
The hormones, experts believe, somehow seem to guard against heart disease, the biggest killer of Americans. Dr. Roy Walford, a UCLA physician and researcher, writing in his book, “The 120 Year Diet,” calls heart disease “the greatest epidemic mankind has ever faced, carrying off a larger percentage of the population than the Black Death in the Middle Ages.”
Walford blames the high-fat, high-cholesterol foods that many Americans favor.
Women have the same eating patterns, yet their arteries do not become clogged, the precursor of heart attacks.
“It’s unknown why this is so,” said Suzanne G. Haynes of the National Center for Health Statistics.
Heart Attack Deaths
What is known is that heart attacks kill about twice as many men as women. For every 100,000 white males, 249 died of heart disease in 1984; the comparable figure for white females was 124.
Some of women’s biological edge is being eroded by smoking, which became fully respectable for American women only after World War II. Lung cancer may soon displace breast cancer as the most common form of cancer that kills women, and smoking also increases the chances of heart attacks.
Smoking is declining among both sexes, but faster for men than for women. Some 32% of adult American men now smoke, barely more than the 28% of women. But there is an ominous trend among young women: In the 20-to-24 age bracket, more women than men smoke.
And the longevity gap may be narrowing with the smoking gap. In 1979, newborn girls could expect to live nearly eight years longer than boys, but the margin has declined to seven years for newborns in 1985, the most recent year for which data is available from the Department of Health and Human Services.
Although nearly as many women as men now smoke, women usually take better care of their health.
“Men more often deny symptoms or ignore them,” said Paul T. Costa Jr., chief of the laboratory of personality at Baltimore’s Gerontology Research Center. “If a woman has chest pains, she is likely to go to a doctor. A man will say, ‘That’s indigestion from the cheeseburger I had at lunch.’ ”
Women also seem more adept at handling stress, the experts say, because they have more close friends with whom they can discuss personal problems and worries. In the jargon of psychology and psychiatry, they have better “support networks.”
In the days when a woman’s place was thought to be the home, one theory held that women entering the work force would soon begin suffering stress and heart attacks at the same rate as men. But during the past three decades, as the number of women working outside the home climbed dramatically, the female death rate from heart disease has declined sharply--more sharply than for men.
Perhaps, according to a modification of that old theory, women will die at the same rate as men only when they move into the same sorts of high-pressure executive jobs. It is not enough for women to be clerks and secretaries, this hypothesis holds. They will not know real stress until they serve as supervisors and managers.
This theory remains difficult to test, Haynes said, because “the percentage of women in managerial jobs compared to 10 years ago hasn’t varied that much.” But she speculated that as more women become managers, they will handle stress more comfortably than men.
“Women are more likely to discuss their anger with others, to communicate,” she said. “Men are more likely to hold it in or to rage out.”
Even at retirement age, women live longer than men. Having reached 65, women can look forward to an average of 18.6 more years, men to 14.6 more. For those who survive to 85, the outlook is 6.4 additional years for women, and 5.2 for men.
Older men “have less reserve capacity when they need strength,” said Svanborg. In particular, he said, men are more likely than women to lose their vitality when a spouse dies.
For men, the outlook is not all grim. Ramey predicts that medical advances will push life expectancies “well into the 90s” in the next century. Men, she says, have the most to gain because they lag so far behind women now.
“I expect the gap will narrow,” she said, “as we are more successful in keeping the weak ones alive.”
