Does cutting calories increase life expectancy? – DV – 10/11/2024

Is excessive calorie consumption the only reason we live shorter lives? The relationship between calorie intake and longevity is a little more complex, and this is where factors such as genetics come into play. This is precisely what a study published by the scientific journal Nature last Wednesday (10/9/2024) demonstrates, in which almost 1,000 genetically diverse mice were analyzed.

The study, conducted by the Jackson Laboratory in the United States, is available at the National Library of Medicine. from this country, notes that although calorie restriction extended the lives of all rodents, the effect on their health varied. These findings also clarify criteria for measuring life expectancy and health expectancy, two different concepts associated with aging.

Restricting calories to live longer?

In the study, 960 female mice representing a wide range of physiological characteristics were exposed to five different treatments: one group had a normal ad libitum diet; another group will see their calorie intake reduced by 20 percent; while the third group will eat 40 percent fewer calories.

The other two groups were put on an intermittent diet, meaning one group fasted one day a week and the other two days in a row.

In addition, the authors, led by Alison Luciano, collected and collated data from approximately 200 medical examinations, including metabolic, functional and immune characteristics of these mice throughout the rest of their lives.

The researchers found that reducing the diet increased the lifespan of mice. This conclusion was reached by all rodents whose response was proportional to the degree of restriction, but only calorie restriction significantly reduced the rate of aging.

Even those who adopted the 40 percent fewer calories plan saw an improvement in their life expectancy. Thus, cutting calories affects life expectancy, but this depends on age, genetic background and the body’s own resistance to this new scenario, they noted.

In addition, lifespan was increased to the same extent in the lightest and heaviest mice, while those mice that were subjected to high body weight intermittent fasting before the intervention showed no evidence of improvement in this aspect.

Genetics plays an important role

Researchers have had mixed results. For example, mice that lived the longest on a restrictive diet lost the least weight despite eating less, while the animals that lost the most weight tended to have low energy levels and compromised immune and reproductive systems. and shorter life expectancy.

This wide range of results confirms that genetic background plays an important role, the study said.

“Animals that were able to maintain high levels of fat and glucose in their bodies lived longer. And I assume that these animals have an inherent resilience,” explains Gary Churchill, another of the study’s authors, in a conversation with the Spanish newspaper El País.

“These interventions cause stress, and animals that lose weight show you that they are reacting negatively to the diet. In this sense, diets simply reveal something about the nature of the animal,” he adds.

Thus, dietary restrictions affect life expectancy, but not completely, since there are nuances, such as genetics, that play a much more important role than previously thought.

For nearly a century, laboratory research has shown consistent results: If an animal eats less or less frequently, it will live longer. However, scientists have struggled to understand why these types of restrictive diets prolong life and how best to apply them to people.

“If you want to live a long time, there are things you can control during your life, such as diet, but in reality you need a very old grandmother,” Churchill said in statements published by Efe.

Edited by Andrea Ariet with information from Nature Communications, National Geographic, El País and Efe Agency.