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Caloric Restriction: Difference between revisions
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The NIA study on rhesus monkeys found no lifespan extension.{{pmid|22932268}} In a long-term study conducted at the ''Wisconsin National Primate Research Center'' over a period of 20 years on rhesus monkeys, a significantly better health status and a significantly increased lifespan were observed in the group of animals that received a reduced food supply during this period. In this group, 80% of the animals were still alive, compared to only 50% in the normally fed control group. Furthermore, in the animals with calorie restriction, a significantly delayed onset of age-associated diseases such as diabetes, cancer, and brain atrophy, as well as cardiovascular incidents, was observed. The authors of the study conclude that calorie restriction delays the aging process in this primate species.{{pmid|19590001}} | The NIA study on rhesus monkeys found no lifespan extension.{{pmid|22932268}} In a long-term study conducted at the ''Wisconsin National Primate Research Center'' over a period of 20 years on rhesus monkeys, a significantly better health status and a significantly increased lifespan were observed in the group of animals that received a reduced food supply during this period. In this group, 80% of the animals were still alive, compared to only 50% in the normally fed control group. Furthermore, in the animals with calorie restriction, a significantly delayed onset of age-associated diseases such as diabetes, cancer, and brain atrophy, as well as cardiovascular incidents, was observed. The authors of the study conclude that calorie restriction delays the aging process in this primate species.{{pmid|19590001}} | ||
=== 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}}. | |||
When a collection of recombinant inbred mouse strains were tested for lifespan under ad libitum diet and CR (40% reduction compared to ad libitum diet) diet, a wide range of lifespan responses were observed in both ad libitum and CR 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}}. | |||
Similarly, a strong variation in lifespan response to diets was observed when a collection of nearly 200 genetically distinct lines of Drosophila (DGRP: Drosophila Genetic Reference Panel) tested for lifespan in ad libitum (5% Yeast) and CR (0.5% Yeast){{doi|10.2139/ssrn.3420829|Wilson, Kenneth Anthony and Beck, Jennifer and Nelson, Christopher S. and Hilsabeck, Tyler A. and Promislow, Daniel and Brem, Rachel B. and Kapahi, Pankaj, Genome-Wide Analyses for Lifespan and Healthspan in D. Melanogaster Reveal Decima as a Regulator of Insulin-Like Peptide Production (July 16, 2019)}}. In both cases, lifespan response also significantly varied between males and females{{pmid|19878144}}{{doi|10.2139/ssrn.3420829|Wilson, Kenneth Anthony and Beck, Jennifer and Nelson, Christopher S. and Hilsabeck, Tyler A. and Promislow, Daniel and Brem, Rachel B. and Kapahi, Pankaj, Genome-Wide Analyses for Lifespan and Healthspan in D. Melanogaster Reveal Decima as a Regulator of Insulin-Like Peptide Production (July 16, 2019)}}, generating a further layer of complication in understanding the mechanisms of CR. A simple interpretation of these animal studies would suggest that a certain type of CR and IF may not be beneficial, but they can be even deleterious depending on genetic variations and sex{{pmid|30442801}}. Therefore, for human applications of CR and IF, we suggest that individualized genomics and medicine should be established first to take full advantage of CR and IF. | |||
==Effects in Humans== | ==Effects in Humans== | ||