Calorie restriction and aging: review of the literature and implications for studies in humans

[Guest guest]

That ref had some interesting full text's: These can provide a lot of free full text refs.

http://www.ajcn.org/cgi/content/full/78/3/361

Calorie restriction and aging: review of the literature and implications for studies in humans

Transcriptional patterns suggest that CR retards aging by causing a metabolic shift toward increased protein turnover and decreased macromolecular damage (161). {rats}

http://jcem.endojournals.org/cgi/content/full/88/7/3454

Dubious Assumptions Underlying the Adjustment of Metabolic Rates for Changes in Fat-Free Mass

Specifically, organs such as liver, brain, kidney, and heart account for only approximately 5% of total body weight (6–7% of FFM); in reference male and female, they collectively account for 58–59% of whole body REE (7). If the mass of one or more high-metabolic-rate organs were to decrease in greater proportion than the mass of low-metabolic-rate organs, REE normalized for FFM would be lower, although the energy flux (kilocalories per kilogram per day) of each organ remained unchanged.

http://jcem.endojournals.org/cgi/content/full/88/7/3454-a

Authors’ Response: Dubious Assumptions Underlying the Adjustment of Metabolic Rates for Changes in Fat-Free Mass

We agree that lean mass heterogeneity may play a role in energy expenditure changes with DR. However, until organ mass changes are characterized in rhesus monkeys, we believe that conclusions about the role organ mass alterations may play in the actions of DR are not yet possible. Given our results, such studies are needed once the precision of the technology can be demonstrated.

http://content.nejm.org/cgi/content/full/337/14/986?ijkey=80dc9c60ccb1a345585ebf73bbc1add94c7bed36 & keytype2=tf_ipsecsha

In a study in which the body weight of genetically obese (ob/ob) C57BL/6J mice was kept at a normal level (approximately 35 g) by caloric restriction, the maximal life span of the animals increased by about 50 percent, despite the fact that their body fat (48 percent), although less than that in unmanipulated ob/ob mice (67 percent),12 was still more than twice that in genetically normal control mice (22 percent). The ob/ob mice with restricted caloric intake lived longer than the genetically normal controls and about as long as the genetically normal mice with restricted caloric intake and 13 percent body fat. In this study, the level of food consumption, not the degree of adiposity, was the key factor in prolonging life.

{I believe that's interesting. Are these female mice?}

http://jcem.endojournals.org/cgi/content/full/88/1/14?ijkey=edaf673a14f9fab52a1060842be18e97c95f2de7 & keytype2=tf_ipsecsha

Reduced Metabolic Rate after Caloric Restriction—Can We Agree on How to Normalize the Data?

Clearly, the next step is to pursue the question of whether a reduction in energy expenditure plays a role, if any, in the life-extending properties of caloric restriction. Given that the present study was performed in male rhesus monkeys and gender differences have been noted in resting metabolic rate (11, 12) and in the energy content of weight change (3), it will be of interest to eventually examine gender-related differences in caloric restriction.

Arciero PJ, Goran MI, Poehlman ET 1993 Resting metabolic rate is lower in females than males. J Appl Physiol 75:2514–2520[Abstract]

Our results support a lower RMR in women than in men that is independent of differences in body composition and aerobic fitness.

Regards.

----- Original Message -----

From: jwwright

Sent: Thursday, May 19, 2005 9:49 AM

Subject: Re: [ ] 10% CR increases longevity - energy expenditure

Here's the full text on an animal I think is closer:

http://jcem.endojournals.org/cgi/content/full/88/1/16