Could cut 5 years from American life spans

A recent special report in The New England Journal of Medicine finds that in coming decades, epidemic levels of obesity could shorten U.S. life spans by 2 to 5 years. (2005;352[11]:1138-1145).

"All predictions are subject to some doubt, but our estimates indicate that in the near future, obesity will decrease life spans by 4 to 9 months," says UAB Professor of Biostatistics David B. Allison, PhD, coauthor of the New England Journal report. "In the slightly more distant future — if nothing radically changes — this decline may shave off years of life span."

Although an accompanying editorial calls the predictions "excessively gloomy," Dr. Allison notes their estimates were conservative, based on the assumption that in the future, obesity levels and obesity-related deaths would remain static.

The paper's lead author, University of Illinois demographer S. Jay Olshansky, PhD, began considering American life expectancy in light of Social Security Administration (SSA) projections that life spans would continue to increase, reaching about 85 years by midcentury. SSA bases its projections on historical data, while Dr. Olshansky's team evaluated current trends in health and mortality.

Dr. Olshansky called on Dr. Allison's group to help factor obesity into the longevity equation by providing data on the relationships among obesity, mortality rate, and life span. An earlier paper by Dr. Allison et al estimated that in some cases, even moderate obesity can result in up to 5 years of life lost (JAMA. 2003;289:187-193).

Key Factor

Obesity has increased 100% since 1980, Dr. Allison says, noting that minorities and children have experienced the most dramatic increases. "Childhood obesity has doubled in the last 25 years, and many obese children will become obese adults. As they age, today's 10-year-olds will experience higher rates of diabetes, cardiovascular disease, and cancer than their contemporary counterparts."

The New England Journal report notes, "...in the absence of successful interventions, it seems likely that (the largest negative impact due to obesity) will be in the first of half of this century, when at-risk populations reach the greatest ages of vulnerability."

"The high economic cost and rising number of deaths due to obesity have been reported before. This study is yet another indicator of the profound nature of the problem and will hopefully serve to vitalize society, underscoring the need for interventions that successfully prevent or treat obesity," Dr. Allison says. "Our estimates are based on the assumption that nothing will change; we hope society proves us wrong."