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:2/27/2017)... --  Strategic Cyber Ventures , the industry,s first cybersecurity ... million investment in  Polarity , the first commercial human ... based and is led by cybersecurity veterans Tom ... Gula , also a longtime cybersecurity veteran and founder ... A round of funding. This new funding will be ...
(Date:2/21/2017)... Der weltweite Biobanking-Sektor wird bis ... Gespräch mit mehr als 50 Vertretern aus verschiedenen Branchen wurde ... um diese Prognose zu realisieren. ... Zu den Schwierigkeiten ... Mittel für die Biobank, die Implementierung Zeit sparender Technologien, ...
(Date:2/10/2017)... Research and Markets has announced the addition of ... Commercial Aspects" to their offering. ... Biomarkers play an important ... selection of treatment as well for monitoring the results. There ... modern medicine. Biochip/microarray technologies and next generation sequencing are also ...
Breaking Biology News(10 mins):
(Date:3/23/2017)... 23, 2017  GlobeImmune, Inc. today announced it has ... of 12,835,490 shares of its common stock to NantCell, ... connection with the sale of its common stock, NantCell ... issue to GlobeImmune 200,000 shares, an estimated $2.0 million ... "We are pleased to enter into this strategic agreement ...
(Date:3/23/2017)... March 23, 2017 NetworkNewsWire Editorial Coverage  ... Cancer ... significant strain on health care systems, in terms of costs ... so too does the development of innovative and efficient therapies ... Among the many types of cancer treatments, a growing number ...
(Date:3/23/2017)... ... March 23, 2017 , ... Advanced Polymer Monitoring Technologies ... Dr. Sigmund “Sig” Floyd as Vice President ? Global Business Development. Dr. Floyd ... , “Dr. Floyd’s career has spanned 30 years in the chemicals and equipment ...
(Date:3/22/2017)... 2017  UBM and the Massachusetts Medical Device ... partnership and the third annual Massachusetts Medtech Week. Massachusetts ... st Annual MassMEDIC Conference held in conjunction ... 2017. MassMEDIC will feature a ... and CEO, Scott Whitaker , at its ...
Breaking Biology Technology: