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

[Guest guest]

Hi JW:

These are EXCELLENT references to some of the key CR studies. If you

find more please post them. Muchas gracias.

Rodney.

--- In , " jwwright " <jwwright@e...>

wrote:

> 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.

> 11.. 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