March 17, 2005
Exploding Obesity May Reduce Average Life Expectancies

A group of researchers including well known names Jay Olshansky and Leonard Hayflick are arguing that average American life expectancy may drop due to rising rates of obesity.

Over the next few decades, life expectancy for the average American could decline by as much as 5 years unless aggressive efforts are made to slow rising rates of obesity, according to a team of scientists supported in part by the National Institute on Aging (NIA), a component of the National Institutes of Health (NIH) of the Department of Health and Human Services (DHHS).

The U.S. could be facing its first sustained drop in life expectancy in the modern era, the researchers say, but this decline is not inevitable if Americans — particularly younger ones — trim their waistlines or if other improvements outweigh the impact of obesity. The new report in the March 17, 2005 issue of The New England Journal of Medicine appears little more than a year after the DHHS unveiled a new national education campaign and research strategy to combat obesity and excessive weight.

The new analysis, by S. Jay Olshansky, PhD, of the University of Illinois at Chicago, Leonard Hayflick, Ph.D., of the University of California, San Francisco, Robert N. Butler, M.D., of the International Longevity Center in New York, and others* suggests that the methods used to establish life expectancy projections, which have long been based on historic trends, need to be reassessed. This reevaluation is particularly important, they say, as obesity rates surge in today’s children and young adults.

“Forecasting life expectancy by extrapolating from the past is like forecasting the weather on the basis of its history,” Olshansky and his colleagues write. “Looking out the window, we see a threatening storm — obesity —that will, if unchecked, have a negative effect on life expectancy.”

Note this is not a new idea. Other researchers have made this suggestion. In fact, this expectation is extremely obvious. We know in increasing detail the ways that obesity changes metabolism for the worse.

My reaction: This is a sort of "if all is is equal" sort of study. It is a really big and improbable "If" in my view: If we do not develop drugs and gene therapies and other treatments to reverse the epidemic of obesity and if we develop no ways to reverse the metabolic damage caused by obesity and if we do not develop new rejuvenation therapies then, yes, life expectancies will decline. But of course we are going to develop all of those things. 50 years from now obesity will be a rarety. Rejuvenation therapies will be cheaply and widely available. Life expectancies will be rising rapidly.

In fact, one National Institute of Aging scientist states the obvious in the press release for this study:

Unlike historic life expectancy forecasts, which rely on past mortality trends, the Olshansky group bases their projection on an analysis of body mass indexes and other factors that could potentially affect the health and well-being of the current generation of children and young adults, some of whom began having weight problems very early in life. The authors say that unless steps are taken to curb excessive weight gain, younger Americans will likely face a greater risk of mortality throughout life than previous generations.

“This work paints a disturbing portrait of the potential effect that life styles of baby boomers and the next generation could have on life expectancy,” says Richard M. Suzman, Ph.D., Associate Director of the NIA for Behavioral and Social Research. Indeed, Suzman notes, obesity may already have had an effect. The sharp increase of obesity among people now in their 60s, he suggests, may be one explanation why the gains in U.S. life expectancy at older ages have been less than those of other developed countries in recent years.

“But it is critical to note that the reduced life expectancy forecast by the study is not inevitable, and there is room for optimism,” Suzman says. “Government and private sector efforts are mobilizing against obesity, and increased education, improved medical treatments, and reduced smoking can tip the balance in favor of reduced mortality and continued improvements in life expectancy.”

I do not expect education to help much. What we need is gene therapy to reprogram human metabolism to maintain a skinny body weight. Staying at an ideal weight should be and eventually will be made effortless. The big unknown here is just how fast will effective appetite suppressant drugs be developed? We should treat obesity research as an urgent matter deserving greater research efforts just as cancer and heart disease research are treated. Lowering the incidence of obesity would lower the incidence of heart disease, cancer, and a great many other diseases.

My guess is that obesity is still going to be lowering life expectancies for the next 10 years but certainly not 30 years from now. Just how soon the obesity problem will be solved remains to be seen. My guess is it will be solved in 20 years or less. We could solve it faster with more research money though.

Here is the abstract for the article.

As for why I'm an optimist about future human life expectancies start here to learn about rejuvenation therapies and Strategies for Engineered Negligible Senescence (SENS). Then read here for more on rejuvenation.

Share |      Randall Parker, 2005 March 17 12:09 PM  Aging Studies

Post a comment
Name (not anon or anonymous):
Email Address:
Remember info?

Go Read More Posts On FuturePundit
Site Traffic Info
The contents of this site are copyright ©