Re: CR decreases risk of death, but ...

[Guest guest]

Hi Tony:

Thanks for reminding us about that study. To my mind it is certainly

one of the top ten most important CR studies for two reasons.

First, it is in a species to which we are very closely related.

Second, it shows astonishingly large benefits from CR.

More recent information was released from that study in the past year

at a conference, where Barbara Hansen spoke. She reported that these

monkeys were put on CR only at an average age, in human-equivalent

terms, of 50 years. And, even when CR is started that late in life,

the CR monkeys, on 30% restriction, are living 30% longer (NOT just

30% more incremental years after age 50, but a 30% longer total

lifespan) than the ad lib monkeys.

However, there are some difficulties making the comparison between ad

lib in monkeys and ad lib in humans. This is because the monkeys are

not tempted with Beef Bourguinonne, Sole Meuniere, Pizza, Ice cream

and cookies. They would probably eat more if they were! Or put the

other way around, if regular US human males only had monkey chow to

eat they very likely would be eating appreciably less than their

current average of ~2500 calories a day.

This difficulty is one reason I believe that the best way to

determine effective degree of CR in humans may be by comparing the

degree of improvement seen in chemical biomarkers, rather than

attempts to measure caloric intake.

Perhaps a combination of monkey chow and antibiotics will turn out to

be the cure for obesity? ; ^ )))

Rodney.

>

> I chuckled when I finished reading the abstract below. It turns out

> that an ad libitum diabetic monkey outlived the CR monkeys, although

> the median age of survival was higher for the CR monkeys.

>

> Tony

>

>

> Bodkin NL, TM, Ortmeyer HK, E, Hansen BC.

Mortality

> and morbidity in laboratory-maintained Rhesus monkeys and effects of

> long-term dietary restriction. J Gerontol A Biol Sci Med Sci. 2003

> Mar;58(3):212-9. PMID: 12634286

>

> 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

>