Less eat for a longer life: Why an extensive study of mice provides decisive knowledge
Less eat for a longer life: Why an extensive study of mice provides decisive knowledge
The reduction in calorie intake can lead to a slimmer body- and for a longer life . This effect is often the weight reductions and Metabolic changes that are caused by less food . One of the biggest studies 1 to dietary restrictions that have ever been carried out on laboratory animals, as dietary, like dietary Restriction increases the service life.
In the study, in which almost 1,000 mice were involved, which were either fed with low-calorie diets or regular phases of the Fasting, it turned out that such programs actually cause weight loss and associated changes in metabolic. But other factors-including Immodesundheit , genetics and physiological indicators of resilience-seem better to explain how the reduction in calories is associated with an increased lifespan.
"The metabolic changes are important," says Gary Churchill, a mouse geneticist at the Jackson Laboratory in Bar Harbor, Maine, who was heading for the study. "But they do not lead to an extension of the lifespan."
For outsiders, the results underline the complex and individual nature of the body's reaction to calorie -reduced diets. "It reveals the complexity of this intervention," says James Nelson, a biogerontologist at the University of Texas Health Science Center in San Antonio.
The study was published today in the magazine Nature of Churchill and his co-authors, including scientists from Calico Life Sciences in South San Francisco, California, the biotech company that specialized in anti-aging, which has financed the study.
Calories count
Scientists have long known that caloric-lowering measures, i.e. long-term restrictions on food intake, extend the lifespan of laboratory animals. Some studies have shown that intermittent fasting, which contains short phases of the food for food, can also increase the durability.
In order to learn more about how such diets work, the researchers observed the health and lifespan of 960 mice, all of which were genetically individual specimens of a diverse population that reflects the genetic variability of humans. Some mice were placed on calorie -limited diets, another group followed intermittent fasting regimes, and others were allowed to eat freely.
A reduction in calorie intake by 40 percent led to the greatest extension of the service life, but also intermittent fasting and less strict calorie restricts increased the average lifespan. The dietary mice also showed cheap metabolic changes, such as reducing the body fat percentage and blood sugar levels.
However, the effects of the dietary restriction to the metabolism and the service life did not always change synchronously. One of the surprises by the authors was that the mice, which lost most of the weight on a calorie -limiting diet, tends to die earlier than animals that lost relatively moderate quantities.
This indicates that processes beyond the simple metabolic regulation determine how the body reacts to reduced calories. The most important factors for the extension of the lifespan were characteristics that were related to the immunity and function of the red blood cells. The general resilience, which is probably coded in the genes of the animals, was also decisive compared to the stress of reduced food intake.
"The intervention is a stressor," explains Churchill. The most resilient animals lost the least weight, kept their immune function upright and lived longer.
slimness for durability
The results could change the view of scientists on studies on dietary restrictions in humans. In one of the most comprehensive clinical studies 2 to a low-calorie diet in healthy people found that Intervention contributed to reducing the metabolism - a short -term effect that is considered a reference to long -term advantages for the lifespan.
The mouse data of Churchill's team, however, suggests that metabolic measurements may reflect the 'health duration'-the period in which one lives free of chronic diseases and disabilities-but that further metrics are necessary to determine whether such 'anti-aging' strategies can actually extend life.
Daniel Belsky, an epidemiologist who examines aging at Columbia University Mailman School of Public Health in New York City, warns against generalizing mice to people. But he also admits that the study "contributes to the growing understanding that health duration and service life are not the same".
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di Francesco, A. et al. Nature https://doi.org/10.1038/s41586-024-08026-3.
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Redman, L. M. et al. Cell Metab. 27, 805–815 (2018).