Today's children may be facing shorter life span
Obesity and related health problems are to blame, report says
Thursday, March 17, 2005
By PAM BELLUCK
THE NEW YORK TIMES
BOSTON -- For the first time in two centuries, the current generation of
children in the United States may have shorter life expectancies than their
parents, according to a new report, which contends that the rapid rise in
childhood obesity, if left unchecked, could shorten life spans by as much
as five years.
The report, to be published today in The New England Journal of Medicine,
says the prevalence and severity of obesity are so great, especially in
children, that the associated diseases and complications -- Type 2
diabetes, heart disease, kidney failure, cancer -- are likely to strike
people at younger and younger ages.
The report, which wades into several controversial aspects of public
health, is likely to stir debate on both scientific and political grounds.
The health effects of being obese depend on many factors, such as one's
fitness level. And estimating those effects could alter the expected cost
of medical care and the size of pension payouts.
The report says the average life expectancy of today's adults, roughly 77
years, is at least four to nine months shorter than it would be if there
were no obesity. That means that obesity is already shortening average life
spans at a greater rate than accidents, homicides and suicides combined,
the authors say.
And they say that because of obesity, the children of today could wind up
living two to five years less than they otherwise would, a negative effect
on life span that could be greater than that caused by cancer or coronary
heart disease.
"Obesity is such that this generation of children could be the first,
basically, in the history of the United States to live less healthful and
shorter lives than their parents," said Dr. David Ludwig, director of the
obesity program at Children's Hospital Boston, and one of the report's
authors.
"We're in the quiet before the storm," Ludwig said. "It's like what happens
if suddenly a massive number of young children started chain-smoking. At
first you wouldn't see much public health impact." He added, "But years
later it would translate into emphysema, heart disease and cancer."
"There is an unprecedented increase in prevalence of obesity at younger and
younger ages without much obvious public health impact," Ludwig said. "But
when they start developing heart attack, stroke, kidney failures,
amputations, blindness and ultimately death at younger ages, then that
could be a huge effect on life expectancy."
Longevity projections are notoriously slippery and politically charged,
with consequences for issues such as Social Security, corporate pension
plans, health insurance and health care costs. Some demographers and
obesity experts question whether the authors' estimate is overly alarmist.
"Yes, it is almost certain that the risks of these various diseases will
rise as obesity rises in the population, but you also have to assume that
the medical sciences will get better at treating some of these
complications," said Dr. Rudolph Leibel, an obesity researcher at Columbia
University. "Certainly doing that is going to end up costing more, but it
may not end up stripping months or years off life."
An editorial in the same issue of The New England Journal, written by Dr.
Samuel Preston, a demographer at the University of Pennsylvania, raises
similar questions. It suggests that the predictions of decreased life
expectancy might be "excessively gloomy," given potential advances in
medicine and genetic engineering, and the reduction of harmful behaviors
such as smoking.
Preston concludes, however, that "the rising prevalence and severity of
obesity are capable of offsetting the array of positive influences on
longevity."
The report's lead author, Dr. Jay Olshansky, a professor of public health
at the University of Illinois-Chicago, said he considered the report's
projections of reduced life expectancy to be "very conservative, and I
think the negative effect is probably greater than we have shown."
"Hopefully, we can fix obesity so that our projections are wrong,"
Olshansky added. "But we're seeing such large increases in obesity in the
last couple of decades that it's hard to imagine that we're going to be
able to work fast enough."
Estimating the number of obesity-related deaths is controversial, too. In
November, the federal Centers for Disease Control and Prevention said its
earlier estimate that 400,000 people die annually from obesity was
inflated. A revised estimate is expected soon. The New England Journal
report uses an estimate of 300,000 deaths, which some experts contend is
still too high.
The report projected life expectancy by calculating how much longer people
would live if "everyone who is currently obese were to lose enough weight
to maintain an optimal" body-mass index, a measure of the relationship
between the height and weight of a person. The authors believe it is more
accurate than other projections.
The report comes at a time when the country is embroiled in a debate over
Social Security. While the report's authors say they started their research
long before the current debate, they write that "the U.S. population may be
inadvertently saving Social Security by becoming more obese" and dying
sooner, but that "this 'benefit' will occur at the expense of the economy
in the form of lost productivity before citizens reach retirement and large
increases in Medicare costs associated with obesity and its complications."
The authors also have a clear view that the way to combat obesity is to get
people to change their behavior, a prescription that not everyone believes
is feasible.