Re: Benefits of 40 % CR with 1 % restriction

[Guest guest]

Rodney posted the following: This is the paper, referenced in the files here, published in 2003, done by the people who, about six months ago, announced at a conference that preliminary indications are that their 30% CR monkeys appear to be living 30% longer than their ad lib monkeys:"Mortality and morbidity in laboratory-maintained Rhesus monkeys and effects of long-term dietary restriction.Bodkin NL, TM, Ortmeyer HK, E, Hansen BC."Obesity and Diabetes Research Center, Department of Physiology, School of Medicine, University of land, Baltimore 21201, USA."Mortality and morbidity were examined in 117 laboratory-maintained rhesus monkeys studied over approximately 25 years (8 dietary-restricted [DR] and 109 ad libitum-fed [AL] monkeys). During the study, 49 AL monkeys and 3 DR monkeys died. Compared with the DR monkeys, the AL monkeys had a 2.6-fold increased risk of death. Hyperinsulinemia led to a 3.7-fold increased risk of death (p <.05); concordantly, the risk of death decreased by 7%, per unit increase in insulin sensitivity (M). There was significant organ pathology in the AL at death. The age at median survival in the AL was approximately 25 years compared with 32 years in the DR. The oldest monkey was a diabetic female (AL) that lived to be 40 years of age. These results suggest that dietary restriction leads to an increased average age of death in primates, associated with the prevention of hyperinsulinemia and the mitigation of age-related disease.PMID: 12634286"

This does not make sense to me. 3 out of 8 DR monkeys died which gives a 37.5 % mortality.

49 out of 109 AL monkeys died which gives a 45 % mortality. How can that translate into a

2.6 fold increase of death for the AL monkeys? Furthermore the number of DR monkeys seems too small

to provide any meaningful conclusions. If by chance just a single more DR monkey would have died,

mortality of that group would have been 50 % i.e. higher than in the AL group. There must be something

wrong somewhere. Maybe there are gaps in the abstract above? // Ulf.

[Guest guest]

Hi Ulf:

The monkeys at the start were all different ages. Unlike in the case

of mice, there isn't a monkey farm set up somewhere to provide anyone

who ever needs them with 200 monkeys all born at the same time and

otherwise all identical.

So the investigators have to do a little arithmetic to be able to

determine, when a monkey dies, what the significance of that is

within the group.

The conclusions they arrived at were after doing this arithmetic.

In addition, a great deal can be learned from the overall condition

of the monkeys. If a small number of CR monkeys are all

demonstrably healthier than the hundred or so ad lib monkeys then

that is significant. And especially it is interesting when they

autopsy the monkeys that die and find that the CR monkeys in general,

apart from the immediate cause of death, are in much better condition

overall - much less organ pathology, especially.

So it is not simply a matter of calculating the percentage of the

monkeys in each group that have died.

Also, that paper was published in 2003. The announcement of the 30%

longer lifespan of the CR monkeys was some time in 2006, when they

had a lot more data, because it is only recently that the monkeys

started reaching old age.

Rodney.

>

> Calorie Restriction/Optimum Nutrition

> Rodney posted the following:

>

> This is the paper, referenced in the files here, published in 2003,

> done by the people who, about six months ago, announced at a

> conference that preliminary indications are that their 30% CR

monkeys

> appear to be living 30% longer than their ad lib monkeys:

>

> " Mortality and morbidity in laboratory-maintained Rhesus monkeys

and

> effects of long-term dietary restriction.Bodkin NL, TM,

> Ortmeyer HK, E, Hansen BC. "

>

> Obesity and Diabetes Research Center, Department of Physiology,

> School of Medicine, University of land, Baltimore 21201, USA.

>

> " Mortality and morbidity were examined in 117 laboratory-maintained

> rhesus monkeys studied over approximately 25 years (8 dietary-

> restricted [DR] and 109 ad libitum-fed [AL] monkeys). During the

> study, 49 AL monkeys and 3 DR monkeys died. Compared with the DR

> monkeys, the AL monkeys had a 2.6-fold increased risk of death.

> Hyperinsulinemia led to a 3.7-fold increased risk of death (p

<.05);

> concordantly, the risk of death decreased by 7%, per unit increase

in

> insulin sensitivity (M). There was significant organ pathology in

the

> AL at death. The age at median survival in the AL was approximately

> 25 years compared with 32 years in the DR. The oldest monkey was a

> diabetic female (AL) that lived to be 40 years of age. These

results

> suggest that dietary restriction leads to an increased average age

of

> death in primates, associated with the prevention of

hyperinsulinemia

> and the mitigation of age-related disease.PMID: 12634286 "

>

> This does not make sense to me. 3 out of 8 DR monkeys died which

gives a 37.5 % mortality.

> 49 out of 109 AL monkeys died which gives a 45 % mortality. How can

that translate into a

> 2.6 fold increase of death for the AL monkeys? Furthermore the

number of DR monkeys seems too small

> to provide any meaningful conclusions. If by chance just a single

more DR monkey would have died,

> mortality of that group would have been 50 % i.e. higher than in

the AL group. There must be something

> wrong somewhere. Maybe there are gaps in the abstract above? //

Ulf

>

> .

>