Featured Research

from universities, journals, and other organizations

Old age offers no protection from obesity's death grip

Date:
February 5, 2013
Source:
Columbia University's Mailman School of Public Health
Summary:
Obesity kills, giving rise to a host of fatal diseases. But when it comes to seniors, a slew of research has reported an "obesity paradox" that says, at age 65 and older, an elevated BMI won't shorten your lifespan, and may even extend it. A new study takes another look at the numbers, finding the earlier research flawed. The paradox was a mirage: As obese Americans grow older, in fact, their risk of death climbs.

Obesity kills, giving rise to a host of fatal diseases. This much is well known. But when it comes to seniors, a slew of prominent research has reported an "obesity paradox" that says, at age 65 and older, having an elevated BMI won't shorten your lifespan, and may even extend it. A new study takes another look at the numbers, finding the earlier research flawed. The paradox was a mirage: As obese Americans grow older, in fact, their risk of death climbs.

Ryan Masters, PhD, and Bruce Link, PhD, at Columbia University's Mailman School of Public Health, in collaboration with Daniel Powers, PhD, at the University of Texas published the results online in the American Journal of Epidemiology.

The researchers argue that past studies of longevity and obesity were biased due to limitations of the National Health Interview Survey, or NHIS, which provides information on obesity. The survey excludes individuals who are institutionalized, such as in a hospital or nursing home -- a group largely made up of seniors. Consequently, the data is overrepresented by older respondents who are healthy, including the relatively healthy obese. What's more, many obese individuals fail to make it to age 65 -- and thus do not live long enough to participate in studies of older populations.

"Obesity wreaks so much havoc on one's long-term survival capacity that obese adults either don't live long enough to be included in the survey or they are institutionalized and therefore also excluded. In that sense, the survey data doesn't capture the population we're most interested in," says Dr. Masters, a Robert Wood Johnson Foundation Health & Society Scholar at Columbia's Mailman School and the study's first author.

In his analysis Dr. Masters matched NHIS data on obesity with corresponding records in the National Death Index using data from close to 800,000 adults surveyed between 1986 and 2004. Next he performed statistical adjustments to account for the survey selection biases. The result: risk for death from obesity increases with age.

The finding jibes with countless medical studies that document how obesity takes a cumulative, even compounding toll on the human body. (Exponents of the obesity paradox have explained their counterintuitive results by suggesting that obesity's extra padding protects seniors from fall-related injuries and provides energy reserves during illness.)

"This study should put to rest the notion that it's possible to 'age out' of obesity risk, and provides a powerful counterfactual against those who say concern over obesity is overhyped," says Dr. Link, a professor of Epidemiology and Sociomedical Sciences at the Mailman School.

Going forward, Dr. Masters has set his sites on another possible reason behind the obesity paradox -- that some of the older obese captured in NHIS data only put on extra weight later in life.

"The recent obesity epidemic hit all age groups at the same time, meaning many of the elderly obese only gained their excess weight in the last 10 years or so," Dr. Masters says. "To account for this fact, I will take a page from studies of cigarette smokers by looking at 'life years' to measure how long someone has been obese rather than whether or not they happen to be obese at the time of a single snapshot survey."

Funding was provided by the Robert Wood Johnson Foundation Health & Society Scholars Program.


Story Source:

The above story is based on materials provided by Columbia University's Mailman School of Public Health. Note: Materials may be edited for content and length.


Journal Reference:

  1. R. K. Masters, D. A. Powers, B. G. Link. Obesity and US Mortality Risk Over the Adult Life Course. American Journal of Epidemiology, 2013; DOI: 10.1093/aje/kws325

Cite This Page:

Columbia University's Mailman School of Public Health. "Old age offers no protection from obesity's death grip." ScienceDaily. ScienceDaily, 5 February 2013. <www.sciencedaily.com/releases/2013/02/130205123744.htm>.
Columbia University's Mailman School of Public Health. (2013, February 5). Old age offers no protection from obesity's death grip. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2013/02/130205123744.htm
Columbia University's Mailman School of Public Health. "Old age offers no protection from obesity's death grip." ScienceDaily. www.sciencedaily.com/releases/2013/02/130205123744.htm (accessed July 28, 2014).

Share This




More Health & Medicine News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
West Africa Gripped by Deadly Ebola Outbreak

West Africa Gripped by Deadly Ebola Outbreak

AFP (July 28, 2014) The worst-ever outbreak of the deadly Ebola epidemic grips west Africa, killing hundreds. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. Video provided by Newsy
Powered by NewsLook.com
Google's Next Frontier: The Human Body

Google's Next Frontier: The Human Body

Newsy (July 27, 2014) Google is collecting genetic and molecular information to paint a picture of the perfectly healthy human. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins