To prolong life, you need the right low-calorie diet
Monkeys have almost confirmed the benefits of moderation in food
Kirill Stasevich, Compulenta
"Moderation in food is the surest way to prolong your life." We hear this so often that it may seem as if it has been a "medical fact" for a long time, confirmed by statistical and experimental studies. However, as far as experimental confirmation of the benefits of moderation in food is concerned, there are, as they say, nuances. It is clear that this kind of work is carried out on animals, but what kind of animals are these? Mainly rodents, nematode worms, fruit flies, etc. If we ourselves want to follow the recommendation to eat less in order to live longer, this pattern should be checked on monkeys.
There was a problem with monkeys: in 2012, a group of researchers from the National Institute of Aging (USA) showed that diet does not affect the life expectancy of primates in any way. The disappointment of scientists dealing with aging was great, but short-lived: recently an article was published in Nature Communications in which experts from the University of Wisconsin-Madison (USA) report that calorie restriction still affects the lifespan of monkeys (Colman et al., Caloric restriction reduces age-related and all-cause mortality in rhesus monkeys).
The study was long-lasting: 72 Rhesus were observed as early as 1989. Half of the macaques were allowed to eat as much as they wanted, while others were restricted in calorie intake by 30%. As a result, it turned out that the death rate and the probability of age-related diseases were three times higher in gluttons than in moderate-eating monkeys.
Figure from an article in Nature Communications: mortality from age-related diseases (a) and from all causes (b)
in the control group and among monkeys on a restricted diet (caloric restriction, CR) – VM.
Here we should be happy for the macaques (and for us too), because they seem to have confirmed that primates can prolong their lives by slightly limiting themselves in food. However, the most interesting thing about all this is why the result suddenly diverged from the 2012 work (also, by the way, published in Nature). Analyzing this question, you can see that with regard to diet and life expectancy, everything can be much more complicated than it seems at first glance, and that the composition of these calories, for example, can play a big role here. Rosalyn Anderson and her colleagues from the University of Wisconsin gave monkeys food containing 30% sugar, while researchers from the Institute of Aging fed the wards unprocessed grain with 4% sugar.
In addition, in the last study, all monkeys were fed to the brim with what they like for some time before the experiment, and then for some individuals, calories were reduced by 30% from their usual portion. As a result, the absolute number of calories varied in both groups – after all, each monkey had its own "norm". And in a two-year-old study, monkeys were given a fixed number of calories calculated from their age and weight, and, accordingly, a 30 percent reduction was calculated in the same way. Because of this, the monkeys in the works differed in weight: The Wisconsin scientists had heavier ones than macaques usually have, and the researchers from the Institute of Aging had lighter ones. Normal weight is always a certain range of values, and Wisconsin monkeys after calorie restriction turned out to be of normal weight, but closer to the upper limit, and primates from the Institute of Aging – with a weight approaching the lower limit of the norm.
In other words, the first study compared the effect of a small calorie restriction with the effect of a serious restriction, and no difference was noticed. And in the current study, scientists compared the effect of calorie restriction with the effect of the absence of such a restriction – and there was a difference. But this is the explanation of scientists from Wisconsin. At the Institute of Aging, the reason for the longevity of Wisconsin monkeys is seen in another way: they lived longer because they did not have metabolic disorders associated with overweight and a large amount of sugar consumed (recall: 30% in Wisconsin versus 4% in the Institute of Aging). But we know about the harm of being overweight even without monkeys, and now we are interested in something else: will there be a benefit from moderation in food if the weight and metabolism of an individual are normal?
In short, the new work has not so much medical and applied as scientific and methodological significance: the described discrepancies in the results once again demonstrated the enormous difficulties that researchers face when planning an experiment and interpreting its results. Usually such things do not go beyond the laboratories, because the general public is not interested in such abstract questions. However, sometimes it is useful for the general public to be reminded of how sophisticated the work of the mind is behind simple and obvious results.
However, in this case it is too early to talk about simple and obvious results: both groups have just begun to compare the results in order to understand what factors - dietary, genetic, environmental, etc. – the relationship between calories and longevity may depend on...
Prepared based on the materials of the University of Wisconsin-Madison:
Monkey caloric restriction study shows big benefit; contradicts earlier study.
Portal "Eternal youth" http://vechnayamolodost.ru02.04.2014