Old age is far from kind to the body, as the unfortunate truth goes. So
when the theory surfaced that growing older could shield people from the
increased risk of death associated with obesity, some rejoiced at the
idea that their later years could be extended in spite of (or because
of) imperfect health.
The "obesity paradox" has been researched
extensively, and scientists have seen better-than-expected outcomes for
obese patients with conditions as serious as heart failure and cardiovascular disease. Dr. Carl J. Lavie made waves in the medical world with his study of the phenomenon, Obesity and Cardiovascular Disease.
"Obesity is a major problem that contributes significantly to increased risk of heart disease and mortality," Lavie said.
"But once you get high blood pressure, blocked heart arteries, and
peripheral arterial disease, the obese patients do better than the lean
patients. The obesity paradox has been written about for years, but
still many doctors are not aware of it."
Sound too good to be
true? It did to Dr. Ryan Masters and his fellow researchers at
Columbia's Mailman School of Public Health, who published contradictory
research last week in the American Journal of Epidemiology.
Using
data from the U.S. National Health Interview Survey and the National
Death Index of people ages 25 to100, the researchers found that previous
evidence supporting the obesity paradox may have been flawed, giving
the impression that obesity offers an advantage to older people.
However,
Masters said, “the obesity-mortality association is not as large as
expected, and often appears to be robust only among the extremely
obese.” He said that the association between obesity and an increased
risk of death is grounded in conventional ideas of how obesity affects
the body, particularly in old age.
“Our current findings suggest
that, indeed, the obesity-mortality association is strongly biased by
selection effects, and once these are accounted for the effect of
obesity on mortality risk grows stronger with age," he said.
Flaws in the Data
Masters
blames biases in previous research data for propagating the idea that
obesity can act as a barrier to mortality in the elderly.
“When
researchers have looked at variation in the ways obesity affects
mortality by age they have given little thought to biases that might
exist in the data they’ve used," Masters said. "They’ve simply presumed
that the samples are truly random. But it's likely that the samples are
biased, especially at older ages, and this bias is likely more
pronounced among the obese population.”
For example, the data
used to draw the "obesity paradox" conclusion excluded people who were
institutionalized in hospitals and nursing homes, a group that includes
many seniors. Moreover, the data gathered for people 65 years old and
older necessarily left out those who did not live to see 65, including
many obese individuals who died from co-morbidities like heart attacks
and strokes.
In the debate over the "obesity paradox," the very notion of what constitutes good health is at stake.
“To
give [the obesity paradox] credence bolsters the flippant and
dismissive responses some scholars and media personnel have made to
rapidly rising rates of obesity in the U.S. population,” Masters said.
“That is, the obesity paradox has been used to dismiss the public health
worry about rising obesity rates as a moral panic. We think such
dismissal is premature, and greater attention needs to be paid to the
deleterious health consequences of high body mass on the U.S.
population’s health.”
Can Obesity Really Be Healthy?
No
doctors, whether they believe in the "obesity paradox" or not, would
encourage patients to gain excess weight or remain obese in order to
better fight mortality down the road.
“Obesity is not a status
that instantly translates into poor health and shorter life, but rather
has a latent, cumulative, compounding toll,” Masters said. “The greater
duration of time spent obese the greater the effect on health and
longevity. Thus, I think it’s imperative to intervene early and be
mindful of nutrition and exercise across the entire life course.”
Additional Resources:
Morbid Obesity
Obesity Treatment : Treatment Search
Diet and Weight 101
Weight Loss Plan Basics
