In the last three decades, different studies with animals seem to confirm that eating little is beneficial for health, because, among other things, it reduces the risk of developing diabetes, cancer or cardiovascular diseases . Some experts argue that this practice, called caloric restriction – reducing intake and therefore calories, but without falling into malnutrition – can even prolong life. However, this phenomenon has been the subject of debate among experts.
Thus, in 2012 the results of a trial with Rhesus macaques started in 1987 that refuted this last aspect were known. The primates that during those 25 years had ingested 30% fewer calories had lower levels of cholesterol and sugar in old age than those who had eaten freely, but the individuals in both groups lived the same life and died from the same causes.
And yet, two years later, another similar experiment of the same duration with the same species of monkeys suggested the opposite: the macaques that had eaten less not only looked better, but lived longer. A few months later, at the end of 2014, a team of researchers from the Harvard University School of Public Health signed a study in the journal Cell in which it was indicated that this habit stimulated the production of hydrogen sulfide , a compound that it helped to protect some parts of the cells from the effects of oxidative stress.
Now, an international group of scientists has presented the findings of extensive research that seems to confirm that while calorie restriction is beneficial to health, it does not necessarily improve longevity . The trial has been coordinated by the US National Institutes of Health, and experts from the Andalusian Center for Developmental Biology and the University of Córdoba (UCO) have participated in it.
In a statement from this same institution, one of those responsible for the trial, the professor of the Department of Cell Biology, Physiology and Immunology of the UCO José Manuel Villalba, points out that although “caloric restriction is the best characterized non-genetic intervention that is can do in an individual to help improve both their health and their life expectancy, the effects on survival are not as universal as previously thought ”. Different factors affect all this, such as sex or the percentage in the reduction of intake.
In an essay published in the journal Cell Metabolism , the authors of this work describe the behavior of mice of both sexes – males are often used in this type of study, although the physiological patterns in females are different – and with two levels of variation of different ingestion, of 20% and 40%, along with others who ate at pleasure and who served as a control group. Researchers found that calorie restriction helped preserve mitochondria , organelles that function as the cell’s powerhouses, and that animals that ate less tended to use more fat than carbohydrates as an energy source, just the opposite of those who ate at will.
These experts warn that although restricting the intake of calories is a stress for the body, when it is not excessive it causes different mechanisms to be activated that in the long run end up protecting the cells. But this does not always guarantee living longer.
Image: University of Córdoba
