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Caloric Restriction: Difference between revisions
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The frequently used [[C57BL/6 mice|C57BL/6]] mice tend to become overweight with unrestricted food access (''ad libitum''). In these animals, the effect of caloric restriction is significant. DBA/2 mice, on the other hand, remain lean even with ad-libitum feeding. In mice from this strain, caloric restriction does not lead to lifespan extension. DBA/2 mice consume more oxygen with the same energy intake than C57BL/6 mice, meaning their metabolic rate is increased – they are poorer "feed converters."{{pmid|19141702}} It was already observed in earlier experiments that caloric restriction is most successful in mice that gain significant weight in early adulthood.{{pmid|958413}} The results of these studies are interpreted to mean that lifespan is more influenced by the balance of energy intake and energy expenditure. Only in test animals prone to overweight or obesity can caloric restriction cause lifespan extension.<ref>{{Cite web|url=https://www.aerzteblatt.de/nachrichten/35192/Lebensverlaengerung-Mythos-der-Kalorienrestriktion-widerlegt|title=Life Extension: Myth of Caloric Restriction Refuted|website=[[Deutsches Ärzteblatt|aerzteblatt.de]]|date=2009-01-26|archive-url=https://web.archive.org/web/20150518230228/http://www.aerzteblatt.de/nachrichten/35192/Lebensverlaengerung-Mythos-der-Kalorienrestriktion-widerlegt|archive-date=2015-05-18|archive-bot=2019-09-14 14:53:42 InternetArchiveBot|access-date=2015-05-01}}</ref> | The frequently used [[C57BL/6 mice|C57BL/6]] mice tend to become overweight with unrestricted food access (''ad libitum''). In these animals, the effect of caloric restriction is significant. DBA/2 mice, on the other hand, remain lean even with ad-libitum feeding. In mice from this strain, caloric restriction does not lead to lifespan extension. DBA/2 mice consume more oxygen with the same energy intake than C57BL/6 mice, meaning their metabolic rate is increased – they are poorer "feed converters."{{pmid|19141702}} It was already observed in earlier experiments that caloric restriction is most successful in mice that gain significant weight in early adulthood.{{pmid|958413}} The results of these studies are interpreted to mean that lifespan is more influenced by the balance of energy intake and energy expenditure. Only in test animals prone to overweight or obesity can caloric restriction cause lifespan extension.<ref>{{Cite web|url=https://www.aerzteblatt.de/nachrichten/35192/Lebensverlaengerung-Mythos-der-Kalorienrestriktion-widerlegt|title=Life Extension: Myth of Caloric Restriction Refuted|website=[[Deutsches Ärzteblatt|aerzteblatt.de]]|date=2009-01-26|archive-url=https://web.archive.org/web/20150518230228/http://www.aerzteblatt.de/nachrichten/35192/Lebensverlaengerung-Mythos-der-Kalorienrestriktion-widerlegt|archive-date=2015-05-18|archive-bot=2019-09-14 14:53:42 InternetArchiveBot|access-date=2015-05-01}}</ref> | ||
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}} | ||
== Mechanism == | == Mechanism == | ||