Featured Research

from universities, journals, and other organizations

Caloric Restriction Research: Moving From Lab Animals To Humans

Date:
July 10, 2002
Source:
The Gerontological Society Of America
Summary:
For more than 60 years scientists have known that restricting the caloric intake in several species of animals can extend life span and slow down the aging process. The prevalence of obesity in America has prompted scientists to consider caloric restriction (CR) research for humans as a way to get America in shape and living longer. For more than 60 years scientists have known that restricting the caloric intake in several species of animals can extend life span and slow down the aging process. The prevalence of obesity in America has prompted scientists to consider caloric restriction (CR) research for humans as a way to get America in shape and living longer.

For more than 60 years scientists have known that restricting the caloric intake in several species of animals can extend life span and slow down the aging process. The prevalence of obesity in America has prompted scientists to consider caloric restriction (CR) research for humans as a way to get America in shape and living longer.

Should scientists subject humans to research studies on CR to see whether it produces the same results in humans as in lab animals? What effect will CR have on psychosocial health and quality of life? Should CR replace other human weight-control strategies? Is CR even possible given the fact that humans have unrestricted access to food?

To answer these and other questions, the National Institute on Aging in collaboration with the National Institute of Diabetes, Digestive, and Kidney Diseases convened the Caloric Restriction Clinical Implications (CRCI) Advisory Group to consider opportunities of such research. The group, which included gerontologists, nutritionists, pharmacologists, physicians, and psychologists, published their findings and recommendations in a special issue of the Journals of Gerontology Series A: Biological Sciences and Medical Sciences (Special Issue I, March 2001, http://www.geron.org/journals/spcontents.html).

Caloric restriction is accomplished by restricting caloric intake far below what an animal would consume on its own. In animal studies, CR was found to extend life expectancy by 30 to 40 percent if initiated in early adulthood.

A panel of experts led by I-Min Lee of Harvard Medical School looked at whether there are physiological effects that occur with CR in humans that could plausibly explain the observed longevity of lab animals associated with CR. They also wrestled with the appropriate CR model in humans. Is it being thin over most of adult life or not gaining weight over time or expending more calories than eaten or eating fewer calories? And more importantly is CR feasible?

Caloric restriction retards diseases and aging among lab rodents, and is now being tested in nonhuman primates with the goal to eventually identify and test agents that may mimic critical actions of CR. The second panel led by Richard Weindruch of the Department Medicine at the University of Wisconsin focused on outcomes of two such agents, oxidative stress and improved glucoregulation.

One aspect of the lab animal paradigm of CR is clearly not applicable to human intervention studies: its involuntary nature. Almost all humans have unlimited access to food, so that some degree of volition must be involved. Panel 3 led by Charles V. Mobbs of the Departments of Neurobiology and Geriatrics at New York's Mount Sinai School of Medicine, assessed the effects of long-term involuntary food restriction.

The distinction between "pure" caloric intake-reducing interventions and alternative weight-loss interventions relates to an issue of practical and mechanistic importance: whether changes in exercise and body composition produce similar changes as those found in dietary restriction. Panel 4 led by Eric Poehlman of the Department of Medicine at the University of Vermont addressed this issue.

Panel 5 led by David B. Allison of the Obesity Research Center at St.Luke's-Roosevelt Hospital in New York focused on genetic factors that might mediate or moderate the effects of CR on longevity. Is there evidence of genetic factors causing variability of the effects of CR on life span and/or age related pathologies? The panel found at least three reasons why it should be valuable to find genes that influence the longevity-promoting effect of CR in humans.

Susan B. Roberts of USDA Human Nutrition Research Center on Aging at Tufts University and her team in Panel 6 recommend medium-term intervention studies in non-obese persons to test benefits of weight-loss interventions against obesity. The panel concluded that the CR benefit in human populations has to be established, so studies in human population are needed to find out whether CR can provide the benefits that have been found in lab animals.

The reports by the Advisory Group presented in the Journals of Gerontology: Biological Sciences and Medical Sciences look at the clinical and basic research opportunities for CR research among humans. The recommendations by the Advisory Group can provide the road map for developing such research.

The Journals of Gerontology Series A: Biological Sciences and Medical Sciences (http://www.gerontologyjournals.org) are refereed publications of The Gerontological Society of America, the national organization of professionals in the field of aging.


Story Source:

The above story is based on materials provided by The Gerontological Society Of America. Note: Materials may be edited for content and length.


Cite This Page:

The Gerontological Society Of America. "Caloric Restriction Research: Moving From Lab Animals To Humans." ScienceDaily. ScienceDaily, 10 July 2002. <www.sciencedaily.com/releases/2002/07/020710081137.htm>.
The Gerontological Society Of America. (2002, July 10). Caloric Restriction Research: Moving From Lab Animals To Humans. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2002/07/020710081137.htm
The Gerontological Society Of America. "Caloric Restriction Research: Moving From Lab Animals To Humans." ScienceDaily. www.sciencedaily.com/releases/2002/07/020710081137.htm (accessed August 21, 2014).

Share This




More Health & Medicine News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Possible Ebola Patient in Isolation at California Hospital

Possible Ebola Patient in Isolation at California Hospital

Reuters - US Online Video (Aug. 20, 2014) — A patient who may have been exposed to the Ebola virus is in isolation at the Kaiser Permanente South Sacramento Medical Center. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Raw: World's Oldest Man Lives in Japan

Raw: World's Oldest Man Lives in Japan

AP (Aug. 20, 2014) — A 111-year-old Japanese was certified as the world's oldest man by Guinness World Records on Wednesday. Sakari Momoi, a native of Fukushima in northern Japan, was given a certificate at a hospital in Tokyo. (Aug. 20) Video provided by AP
Powered by NewsLook.com
Do More Wedding Guests Make A Happier Marriage?

Do More Wedding Guests Make A Happier Marriage?

Newsy (Aug. 20, 2014) — A new study found couples who had at least 150 guests at their weddings were more likely to report being happy in their marriages. Video provided by Newsy
Powered by NewsLook.com
Ebola-Hit Sierra Leone's Freetown a City on Edge

Ebola-Hit Sierra Leone's Freetown a City on Edge

AFP (Aug. 19, 2014) — Residents of Sierra Leone's capital voice their fears as the Ebola virus sweeps through west Africa. Duration: 00:56 Video provided by AFP
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