Junkfood Science: Helping, not harming, seniors

April 26, 2007

Helping, not harming, seniors

A second study released this week tried everything possible to find something to support “obesity as an increasing public health problem.” While headlines ambiguously mentioned obesity may be associated with disability in the elderly, the association this study found was not what most people may have jumped to conclude. Being fat was not associated with increased risk for disability and was associated with the lowest mortality.

Researchers at the University of Texas Medical Branch in Galveston dredged through a database called EPESE (Established Populations for Epidemiologic Studies of the Elderly) which is a collection of demographic, social and health information compiled from surveys of people 65 years or older around the country. The surveys were done annually for seven years. Countless studies looking for correlations between health and disability and socioeconomic factors, social contacts, emotional supports, and quality of care for our elderly have been published using this database. The EPESE data has previously shown that most disability is associated with a recent hospitalization for diseases of aging, hip fracture, dehydration and pneumonia.

These researchers were looking at correlations between obesity and mortality and the development of disability among elderly, so they excluded data on any person who at the beginning of the study period already reported at least one limitation in their activities of daily living (ADLs). Some data was also eliminated for missing pieces of information.

Thus, among the data on 17,358 people, these researchers eliminated 26.6% of the cohort. They admitted that those they excluded were more likely to have a low BMI, have less education, to have had a serious illness, and be older. Already, they acknowledged greater disability was associated with low BMI and health problems. Their study proceeded to look at data from the remaining heavier, healthier elderly. They lost another 11% of those in followup, leaving 65% of the original cohort.

After seven years, 28% of the elderly reported at least one limitation in ADL and this group was notable for being nearly 5 years older (about 76 years old) than those free from disabilities. And 15.8% of the study population had died, again mostly among the older seniors.

Their statistical analysis computed odds ratios for associations with BMI. This study found no strong associations between BMI and disability. Weights most free from disability ranged from “recommended” to “obese.” There were higher risks associated at the extremes of weight (a wide “J” curve), but only at the most extreme “morbidly obese,” a mere 0.5% of the cohort, did the risks for disability become significant.

But being overweight and obese proved to be associated with the lowest risks for mortality and best odds for life expectancy. Even the most “morbidly obese” people still had a lower risk for mortality than underweight people — five time lower, in fact.

“Recommended weights” were associated with higher risks for mortality than being either overweight or obese. Even those at the higher end of obesity with BMIs 35-40 shared the same mortality risks and life expectancies as those at “recommended” BMIs, leaving further questions as to the rationale for current “recommended weights” for older citizens. [Mortality and BMI, with "recommended BMIs" shaded green:]

Now, before you suspect that perhaps the lower BMIs were associated with those suffering from illnesses or smoking, the researchers addressed those concerns by adjusting for smoking and excluding in an analysis all of those who died during the first two years of followup and found little difference. One explanation for the association between obesity and lower mortality among older people, they said, is the protective effects of weight, including “decreased risks for hip fractures and increased ability to tolerate periods of low calorie intake associated with acute illnesses.”

The most carefully-done research has consistently shown the dangers of weight loss, especially among the elderly. What is most incredible is that, despite being unable to demonstrate a concern for “obesity-associated” risks for disability for 99.5% of elderly and finding that being fat is associated with longer life and the lowest risks for mortality, these researchers still advocated for weight intervention and ideal BMI recommendations be based on disability, concluding:

Our results suggest that the association between BMI and mortality is only 1 factor in determining optimal BMI values for older adults. Loss of independence is one of the most feared outcomes experienced by older individuals and is a major contributor to poor quality of life. The association between elevated BMI and subsequent disability provides evidence that obesity in older populations is associated with a substantial increase in risk for poor health outcomes. If this risk is confirmed, values for BMI in older adults should be interpreted accordingly and appropriate prevention and intervention programs developed.

Certainly, few people want to need assistance from others, at any age. But to suggest that simply because of a disability, it might be preferable those people be dead is an unsettling conclusion to make for others.

© 2007 Sandy Szwarc

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