Questão 69437

(Faculdade de Medicina de Jundiaí - 2018)

The hunger gains: extreme calorie-restriction diet shows anti-aging results

    The idea that organisms can live longer, healthier lives by sharply reducing their calorie intake is not exactly new. Laboratory research has repeatedly demonstrated the anti- -aging value of calorie restriction, often called CR, in animals from nematodes to rats – with the implication that the same might be true for humans.

    In practice though, permanently reducing calorie intake by 25 to 50 percent or more sounds to many like a way to extend life by making it not worth living. Researchers have also warned that what works for nematodes or rats may not work – and could even prove dangerous – in humans, by causing muscle or bone density loss, for example.

    But now two new studies appear to move calorie restriction from the realm of wishful thinking to the brink of practical, and perhaps even tolerable, reality. Writing in Nature Communications, researchers at the University of Wisconsin- -Madison and the National Institute on Aging reported last month chronic calorie restriction produces significant health benefits in rhesus monkeys – a primate with humanlike aging patterns – indicating “that CR mechanisms are likely translatable to human health.” The researchers describe one monkey they started on a 30 percent calorie restriction diet when he was 16 years old, late middle age for this type of animal. He is now 43, a longevity record for the species, according to the study, and the equivalent of a human living to 130.

    In the second study, published in Science Translational Medicine, a research team led by gerontologist Valter Longo at the University of Southern California (U.S.C.) suggests it is possible to gain anti-aging benefits without signing up for a lifetime of hunger. Instead, a “fasting-mimicking diet,” practiced just five days a month for three months – and repeated at intervals as needed – is “safe, feasible and effective in reducing risk factors for aging and age-related diseases.”

    Some researchers, however, still find the calorie-restriction argument unpersuasive. Leslie Robert, a biochemist and physician at the University of Paris who was not involved in the two new studies, says pharmaceutical approaches offer greater anti-aging potential than “inefficient and apparently harmful” diets. The important thing, adds Luigi Fontana, a longevity researcher at the Washington University School of Medicine in Saint Louis who also was not involved in the new work, is “if you’re doing a healthy diet, exercising, everything good, without doing anything extreme, without making life miserable by counting every single calorie.”

(Richard Conniff. www.scientificamerican.com, 16.02.2017. Adaptado.)

No trecho do quinto parágrafo “who also was not involved in the new work”, o termo em destaque refere-se a