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Caloric Restriction: Difference between revisions
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=== Genetic Variations === | === Genetic Variations === | ||
In animal models, some physiological and metabolic traits, especially lifespan, are strongly affected by genetic backgrounds and variations as well as non-genetic factors such as symbiotic microbiome and water balance{{pmid|28220799}}. | In animal models, some physiological and metabolic traits, especially lifespan, are strongly affected by genetic backgrounds and variations as well as non-genetic factors such as symbiotic microbiome and water balance{{pmid|28220799}}. The role of particular genes in the response of lifespan to caloric restriction has been investigated by determining if a genetic alteration alters this response. Lifespan rises to a maximum as the food intake is lowered, but can decline rapidly if the food supply is further reduced. Therefore, the effects of mutations should be examined over a broad range of food intakes, so that the degree of caloric restriction that maximizes life span can be determined and used in tests for genetic effects{{pmid|17465680}}. | ||
When a collection of recombinant inbred mouse strains were tested for lifespan under ad libitum diet and caloric restriction (40% reduction compared to ad libitum diet) diet, a wide range of lifespan responses were observed in both ad libitum and caloric restriction diets{{pmid|19878144}}{{pmid|23562825}}. For example, the mean lifespan of female mice on ad libitum diet varied from 407 to 1208 days. Strikingly, their lifespans on CR diet varied to a greater degree from 113 to 1225 days. Importantly, not only did CR fail in lifespan extension in some lines, but it even shortened lifespan in some lines too{{pmid|19878144}}. | When a collection of recombinant inbred mouse strains were tested for lifespan under ad libitum diet and caloric restriction (40% reduction compared to ad libitum diet) diet, a wide range of lifespan responses were observed in both ad libitum and caloric restriction diets{{pmid|19878144}}{{pmid|23562825}}. For example, the mean lifespan of female mice on ad libitum diet varied from 407 to 1208 days. Strikingly, their lifespans on CR diet varied to a greater degree from 113 to 1225 days. Importantly, not only did CR fail in lifespan extension in some lines, but it even shortened lifespan in some lines too{{pmid|19878144}}. | ||