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SCHOLARS WHO PIECE together the story of human progress by comparing
the height and health of our ancestors say the cartoon version -- where
apes give way to stooped hairy cavemen who give way to tall, erect modern
humans -- is wrong. The past three centuries have produced taller,
healthier people, but history is punctuated by periods of improved
stature, health and longevity and periods of plateau or decrease.
The average height of American soldiers, for instance, peaked at 68.3
inches (173.5 centimeters) for those born in 1830 and fell to a nadir of
66.6 inches (169.2 centimeters) for those born in 1890, economic
historians Richard Steckel and Dora Costa document. Among other things,
disease spread by substantial migration around the country in the mid-19th
century took its toll. The trend then reversed: Those born in 1970 average
69.8 inches (177.40 centimeters).
Reconstructing biological history is a way to see both the ebb and flow
of living standards and of the gap between rich and poor. Upper- class
19th-century British men were much taller than lower-class men because
they weren't hungry all the time. When diets of the poor improved, their
children grew taller and the average height of British men rose. Genes
play a huge role in an individual's height, but health, diet and
environment influence societywide averages.
So are we, the beneficiaries of remarkable medical advance and wealth,
on the cusp of another spurt in height, healthy old age and longevity? The
answer may lie, to a surprising degree, in the womb and shortly
afterward.
IN CLEVER WAYS, economic historians are accumulating evidence that
aging begins before birth. We live longer and better not only because
modern medicine cures diseases that killed our grandparents but because
our mothers were better fed and in better health and we were better
treated as infants. Two examples make the point.
In records of men who fought for the Union Army during the Civil War
and lived at least until 1900, Prof. Costa and another researcher at the
Massachusetts Institute of Technology find that those born in spring and
summer died sooner. Men born in April, May or June were 70% more likely to
die of stroke as adults than those born in October, November or December.
Their mothers didn't have as much to eat during the winter, it appears,
and were more likely to have respiratory ailments; spring babies also were
more likely to get infectious diseases with long-lasting effects.
Columbia University's Douglas Almond discovers that sons of pregnant
women who got the flu during the influenza epidemic of 1918 were 20% more
likely to be disabled as adults. Those who survived to the late 1970s
tended to die three years sooner than men whose mothers were spared the
flu. Sons of flu-stricken women were 20% less likely to finish high
school.
That was then. What about now?
The grand old man of this field, Nobel Prize winner Robert Fogel of the
University of Chicago, exudes optimism: "Life expectancy," he says, "will
probably increase at the same rate during the 21st century as it did
during the 20th" -- when life expectancy at birth went to 77 years from
48. "We'll probably add 30 years to life by the end of the century," he
predicts.
His optimism is well-grounded. Month of birth doesn't matter much
anymore: Winter diets have improved and summer-time water-borne diseases
have been conquered. One problem solved. And the onset of debilitating
chronic diseases comes later: Arthritis arrived, on average, 11 years
later at the end of the 20th century than at the beginning. A white man in
his early 60s is 2 1/2 times as likely to be free of chronic disease as
his counterpart a century ago, Prof. Fogel says. But scholars are
scrutinizing another, more puzzling trend: Northern European adults these
days are consistently taller than Americans, and it's not because the U.S.
is drawing short-stature immigrants. The fact inevitably invites
speculation about the ill effects of American fast food, obesity and
lethargy.
Prompted by pesky questions from a New Yorker reporter, Prof. Steckel
of Ohio State University recently began looking at children's heights. His
early finding is that four-year-old Americans are an inch and a half (3.8
centimeters) behind the Dutch, Danes and Swedes. "Kids are about the same
height if they grow up under the same economic conditions.
If the children are small at age four, it's got to be pre- and post-
natal," he says. "It's not French fries or fast food. I'm not saying that
doesn't contribute, but it's not showing up at age four."
What is it? He doesn't know yet. But he is haunted by the evidence that
inequality in 19th-century Europe was reflected in the average height of
the population and wonders if the unevenness of health care and living
conditions in the U.S. is at the root of this.
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