Navigation Links
Eating less may not extend life
Date:1/23/2009

If you are a mouse on the chubby side, then eating less may help you live longer.

For lean mice and possibly for lean humans, the authors of a new study predict the anti-aging strategy known as caloric restriction may be a pointless, frustrating and even dangerous exercise.

"Today there are a lot of very healthy people who look like skeletons because they bought into this," said Raj Sohal, professor at the University of Southern California's School of Pharmacy.

He and Michael Forster, of the University of North Texas Health Science Center, compared the life span and caloric intake of two genetically engineered strains of mice.

The "fat" strain, known as C57BL/6, roughly doubles in weight over its adult life. That strain benefited from caloric restriction, Sohal said.

The "lean" strain, DBA/2, does not become obese. Caloric restriction did not extend the life of these mice, confirming previous work by Forster and Sohal.

The results appeared online Jan. 13 in advance of print publication in the Journal of Nutrition.

"Our study questions the paradigm that caloric restriction is universally beneficial," Sohal said. "Contrary to what is widely believed, caloric restriction does not extend (the) life span of all strains of mice."

By measuring the animals' metabolic rate, Sohal and his colleagues came to a deceptively simple conclusion: Caloric restriction is only useful when, as in the case of the obese mice, an animal eats more than it can burn off.

"Your energy expenditure and your energy intake should be in balance," Sohal said. "It's as simple as that. And how do you know that? By gain or loss of weight.

"The whole thing is very commonsensical."

For humans of normal weight, Sohal strongly cautions against caloric restriction. In a 2003 study, he and Forster found that caloric restriction begun in older mice both in DBA and leaner C57 individuals actually shortened life span.

However, Sohal said that obese individuals are probably better off cutting calories than increasing their exercise to make up for overeating. Overly vigorous exercise can lead to injuries and long-term wear and tear.

In other words, it is better to skip the double cheeseburger than to turn up the treadmill after binging at Carl's Jr.

Sohal's study is not the first to question the allegedly universal benefits of caloric restriction. A study by Ross et al. published in Nature in 1976 ("Dietary practices and growth responses as predictors of longevity") found that caloric restriction works best in mice that gain weight rapidly in early adulthood, Sohal said.

Studies of caloric restriction in wild types of mouse strains have shown minimal life span extension, he added.

Next, the researchers want to understand why the obese mice have a lower metabolic rate that promotes weight gain.


'/>"/>

Contact: Carl Marziali
marziali@usc.edu
213-740-4751
University of Southern California
Source:Eurekalert

Related biology news :

1. Studies point to novel target for treating arrhythmias
2. World breakthrough in treating premature babies
3. Eating habits and exercise behaviors in children can deteriorate early
4. UC Davis discovery offers hope for treating kidney cancer
5. Argonne scientists discover possible mechanism for creating handedness in biological molecules
6. Eating eggs when pregnant affects breast cancer in offspring
7. Pitt research identifies new target in brain for treating schizophrenia
8. How eating fruit and vegetables can improve cancer patients response to chemotherapy
9. Better beer: College team creating anticancer brew
10. Plant-eating predator to fight superweed is not magic bullet
11. Diversity of plant-eating fishes may be key to recovery of coral reefs
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:7/20/2017)... (NYSE: DAL ) customers now can use fingerprints instead of ... Airport (DCA). ... Delta launches biometrics to board aircraft at Reagan Washington National Airport ... Delta,s biometric boarding pass experience that launched in May ... boarding process to allow eligible Delta SkyMiles Members who are enrolled in ...
(Date:6/14/2017)... June 15, 2017  IBM (NYSE: IBM ) is introducing ... event dedicated to developing collaboration between startups and global businesses, ... 15-17. During the event, nine startups will showcase the solutions ... various industries. France ... market, with a 30 percent increase in the number of ...
(Date:5/16/2017)... , May 16, 2017   Bridge ... health organizations, and MD EMR Systems , ... development partner for GE, have established a partnership ... Portal product and the GE Centricity™ products, including ... EMR. These new integrations will ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... (PRWEB) , ... October 11, 2017 , ... Disappearing forests ... the lives of over 5.5 million people each year. Especially those living in larger ... startup Treepex - based in one of the most pollution-affected countries globally - decided ...
(Date:10/10/2017)... ... ... San Diego-based team building and cooking events company, Lajollacooks4u, has unveiled a ... new look is part of a transformation to increase awareness, appeal to new markets ... It will also expand its service offering from its signature gourmet cooking classes and ...
(Date:10/10/2017)... ... ... Dr. Bob Harman, founder and CEO of VetStem Biopharma, Inc. spent ... entitled “Stem Cells and Their Regenerative Powers,” was held on August 31st, 2017 ... joined by two human doctors: Peter B. Hanson, M.D., Chief of Orthopedic Surgery, Grossmont ...
(Date:10/10/2017)... ... October 10, 2017 , ... ... business process optimization firm for the life sciences and healthcare industries, announces a ... in San Francisco. , The presentation, “Automating GxP Validation for Agile Cloud Platforms,” ...
Breaking Biology Technology: