The matter in summary A new study shows that eating fewer calories can extend life, regardless of weight loss. The study followed nearly 1,000 mice with different diets to see which ones extended the animals’ lives. The results showed that diets with fewer calories generally extended the lifespan of the mice, regardless of body fat and glucose levels. It was not the mice that lost the most weight that lived the longest, which suggests that other processes may be important in extending lifespan. The study also found that genetic factors had a greater influence on life expectancy than diet. The researchers believe that studies of people and ageing, which often use metabolic measurements as a basis, may overlook more important aspects of healthy ageing. The summary is made by an AI service from OpenAI. The content is quality assured by news’s journalists before publication. In research, there is almost a race to find answers to what can give us a long and healthy life. And a bunch of animal studies show the same thing time and time again: If the animal eats less food, or has periods of fasting, it often lives longer. But why is that so? And perhaps most important of all – how can this be transferred to humans? Researchers have basically struggled to understand that. But now a new, large study can provide more long-awaited answers. And perhaps the results may surprise, because weight loss should have little to do with the matter. The new research has been published in the renowned journal Nature. Fewer calories were better than fasting In the new study, approximately 1,000 mice followed different types of diets. The animals had a wide genetic diversity. This makes it easier to compare with people, the researchers write. The aim of the study was to see which diets extended the animals’ lives. The results showed, among other things, that eating fewer calories had a greater effect on lifespan than intermittent fasting. They also saw that diets containing fewer calories generally extended the lifespan of the mice. Fasting also had an effect. This was independent of factors such as body fat and glucose level. Both of these are considered important markers for metabolic health and aging. Surprisingly, the animals that lost the most weight did not live the longest. This image shows fat cells. The new study shows that restrictive diets lead to a loss of fat, as well as prolonging the lives of the animals. But it also shows that these two effects are not necessarily connected. Photo: selvanegra / Getty Images/iStockphoto Adding something new – This is a fairly complicated study. But with very interesting and important findings. That’s what Geir Selbæk says. He is professor of geriatrics and head of research at the National Center for Aging and Health. He says it confirms what previous research on animals has shown, but that it also adds something new. – There was no clear connection between the degree of weight loss and increased lifespan. Surprisingly, the mice that lost the most weight did not live the longest. This may indicate that there are other processes that are important for extending the lifespan. This study indicates that it may have something to do with immunity and genetic conditions, explains Selbæk. Selbæk believes that the new study shows that even if something improves our health, it does not necessarily mean that we live longer because of it. Photo: Aleksandr Nedbaev / news Being robust trumps weight loss The study showed that the mice that lost the most weight often had low energy, weakened immune systems and a shorter life. Professor and researcher Gary Churchill says a lot is about resilience. – The most robust animals maintain their weight even in the face of stress and less food. And they are also the ones who live the longest. The researchers tested five different diets in the study: A group of mice could eat as much – and whenever – as they wanted. Group two received 60 percent of their caloric needs over the course of a day. The third got 80 percent of the calories you need in a day. The fourth diet consisted of intermittent fasting one day a week. And the fifth diet had two fasting days during the week. For the remaining days, the mice could eat whatever and whenever they wanted. The health of the animals was then studied until they died. – You want a very old grandmother The mice who could eat freely lived on average just over two years. Those who had fasting periods lived an average of 28 months. Those who ate a certain amount of calories each day lived 30-34 months. Those who ate the least lived the longest. But within each group, life expectancy varied, the researchers write. To find out why, they analyzed the data more closely. They then found that genetic factors had a greater influence on life expectancy than diet. – If you want to live a long time, there are things you can control – for example your diet. But what you really want is a very old grandmother, says Churchill. Casting doubt The new study also helps cast doubt on traditional ideas linked to diets and lifespan, the authors believe. For example, factors such as weight, body fat percentage or blood sugar level did not explain any relationship between cutting calories and longevity. Instead, the study found that immune system health and characteristics were more clearly linked to longevity. This was related to red blood cells. Therefore, the researchers believe that studies of people and ageing, which often use metabolic measurements as a basis, may overlook more important aspects of healthy ageing. Although being restrictive on calories is generally good for longevity, the data in the new study shows that losing weight as a result is not necessarily all good. Mice are not people Daniel Belsky is an epidemiologist and studies aging at Columbia University in New York. He believes the study is good, but that one should be careful in transferring results from mice to humans. Nevertheless, he says that the study is interesting. – It helps to increase understanding that health and longevity are not the same. Here, Geir Selbæk at the National Center for Aging and Health agrees. – It can inspire new and better research into what improves health in the elderly, and perhaps also extends life. In all basic medical research, laboratory mice and other laboratory animals are important. Nevertheless, it is an ethical dilemma to use them in such a context. Photo: ROBERT F. BUKATY / AP Published 18.10.2024, at 19.36
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Eating fewer calories gives mice an increased lifespan – but not due to weight loss – news Trøndelag – Local news, TV and radio
