That eating little helps you live longer it’s been said for a long time, but only now comes the answer to why this is true: the secret lies not in the weight loss and metabolic changes observed, as previously thought, but especially in DNA. This was discovered by one of the largest studies done on the subject, published in the journal Nature, which involved almost 1,000 mice subjected to different diets and observed throughout their lives. The research, led by the biotech company Calico and the Jackson Laboratory, both American, shows that genetic heritage plays the most important role of each individual, that is capable of making the body more or less resilient to the stress caused by caloric restriction.
The researchers, coordinated by the Italian Andrea Di Francesco di Calico and Gary Churchill of the Jackson Laboratory, made the selection 960 topi genetically distinct from each other, in order to better represent the genetic diversity of the human populationand divided them into groups: some could eat freely, while others were subjected to low-calorie diets or regular periods of fasting. A cutting calories by 40% led to the largest increase in average lifespanbut positive results have also been obtained with less severe diets and intermittent fasting.
Nevertheless, much to the surprise of the study authorsThe animals that lost more weight are also those that died earlier. To explain this apparent contradiction is the degree of resilience encoded in genes: the ‘luckiest’ mice from a genetic point of view maintain their body weight, fat percentage and immune system health even when subjected to stress caused by food scarcity, surviving longer. “If you want to live a long time, there are things you can control during your life, such as diet – says Churchill – but what really matters is having a very old grandmother”.
The research he denies itso, the classic ideas on why some diets can prolong life: Factors like weight, body fat percentage and blood glucose levels don’t explain the link between calorie cutting and living longer. This means that human studies on longevityoften based on these parameters, probably neglect more important aspects related to aging, such as immune system health. “While the Caloric restriction is generally positive for lifespan – conclude Churchill – losing weight is not”.
