RE: Low Body Weight and CR -- Both Help You

[Guest guest]

Proof that reduced caloric intake -- and not reduced fatness --

is the major factor that increases lifespan. -- Warren

See last sentence of text below.

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Proc Natl Acad Sci U S A. 1984 Mar;81(6):1835-8.

Related Articles, Links

Effects of Food Restriction on Aging: Separation of Food Intake

and Adiposity.

on DE, Archer JR, Astle CM.

Restricted feeding of rodents increases longevity, but its

mechanism of action is not understood. We studied the effects of

life-long food restriction in genetically obese and normal mice

of the same inbred strain in order to distinguish whether the

reduction in food intake or the reduction in adiposity

(percentage of fatty tissue) was the critical component in

retarding the aging process. This was possible because food-

restricted obese (ob/ob) mice maintained a high degree of

adiposity. In addition to determining longevities, changes with

age were measured in collagen, immune responses, and renal

function. Genetically obese female mice highly congenic with the

C57BL/6J inbred strain had substantially reduced longevities and

increased rates of aging in tail tendon collagen and thymus-

dependent immune responses, but not in urine-concentrating

abilities. When their weight was held in a normal range by

feeding restricted amounts, longevities were extended almost 50%,

although these food-restricted ob/ob mice still had high levels

of adiposity, with fat composing about half of their body

weights. Their maximum longevities exceeded those of normal

C57BL/6J mice and were similar to longevities of equally food-

restricted normal mice that were much leaner. Food restricted

ob/ob mice had greatly retarded rates of collagen aging, but the

rapid losses with age in splenic immune responses were not

mitigated. Thus, the extension of life-span by food restriction

was inversely related to food consumption and corresponded to the

aging rate of collagen. These results suggest that aging is a

combination of independent processes; they show that reduced food

consumption, not reduced adiposity, is the important component in

extending longevity of genetically obese mice.

PMID: 6608731 [PubMed - indexed for MEDLINE]

[Guest guest]

This article on exercise (a variable that is independent of both

body weight and CR) has results that I found interesting. The effect

of exercise increased lifespan by 9% in the following study -- but

was not statistically significant within measurement error for

the animal cohort sample size used in the study. -- Warren

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[1] Mech Ageing Dev 1998 Feb 16;100(3):211-9 Related Articles, Books,

LinkOut

Longevity of exercising male rats: effect of an antioxidant supplemented

diet.

Holloszy JO.

Department of Medicine, Washington University School of Medicine, St. Louis,

MO 63110, USA.

Food restriction increases maximal life span in rodents. Male rats that

exercise in voluntary running wheels do not have an increase in maximal

longevity despite a relative caloric deficit. In contrast, sedentary rats

that are food restricted so as to cause the same caloric deficit have an

extension of maximal longevity. It seemed possible that exercise-induced

oxidative stress might prevent a maximum life span-extending effect of a

caloric deficit to manifest itself. This study was done to determine if

antioxidants would allow a maximal longevity-extending effect of exercise to

manifest itself in male rats. The antioxidant diet had no effect on

longevity of the runners (Antiox., 951 +/- 158 days versus control 937 + 171

days), or of the sedentary controls (875 +/- 127 versus 858 +/- 152 days).

As in previous studies, wheel running modestly increased average longevity

(approximately 9%), but had no effect on maximal life span. The finding that

antioxidants had no effect on longevity of the wheel runners supports the

interpretation that the caloric deficit induced by exercise in male rats

does not have a life-extending effect that is countered by oxidative tissue

damage.

PMID: 9578110