Aging Aging

Dietary Restriction 35325Dietary Restriction and Life-Span ExtensionByung Pal Yu1. IntroductionThe popularity of the dietary restriction (DR) paradigm (often used interchangeablywith calorie restriction) among gerontologists is primarily basedon the research finding of the last two decades. Originally discovered byMcCay’s group in the 1930s, this paradigm showed that animals placed on theDR regimen, meaning reduced nutrition without malnutrition, had robust lifeextensions (1). This scientific breakthrough showed that nutritional status canbring about distinctive metabolic adjustments.Among the most obvious phenotypic changes seen with the implementationof DR are reduced body weight or size, slow growth, leanness due to reducedadipose mass, young appearance, and agility. The hallmark of these age-relatedchanges, however, is a robustly extended life-span, accompanied by low morbidityand mortality rates (2). The life prolonging action of DR is unparalleledwith any other laboratory paradigm in its ability to induce such a broad spectrumof physiological and pathological anti-aging effects (3). The unequivocalexperimental data confirmed by many laboratories around the world have establisheddietary intervention as the most effective and dependable tool or procedureavailable tool today for gerontologists in their exploration of the agingprocess.As an experimental tool, DR has at least three important characteristics thatmake it the gold standard of aging research (1,4,5). They are as follows:1. Simplicity of execution: Studies using this paradigm are simple to execute and theprocedures are easy to implement. Unlike other nutritional manipulations inwhich either individual dietary components or ingredients are adjusted eitherquantitatively or qualitatively, DR can be administered by simply reducing theamount of the food given, thereby resulting in the calorie restriction. This simple-From: Methods in Molecular Medicine, Vol. 38: Aging Methods and ProtocolsEdited by: Y. A. Barnett and C. R. Barnett © Humana Press Inc., Totowa, NJ353