Starve, don't starve – you're gonna die anyway

About the futility of fasting to prolong the life of primates

YuriDeigin, Geektimes

In the early 90s, an interesting two-year experiment was conducted in America called Biosphere-2. Eight people were isolated from the outside world in a kind of Martian colony. As part of this experiment, scientists were going to study a number of things, but personally I am interested in it because one of the researchers there was the famous evangelist of therapeutic fasting, Roy Walford. Who persuaded the rest of the “crew members” to starve for almost all 2 years. Here is the Swarm itself at the end of the experiment (left):

By the way, at that time he was 69 years old, and thanks to starvation, Roy was going to live up to 120. Alas, he did not succeed – he died at 79. But this does not stop the adherents of fasting. Recent debates with them made me once again dig through various studies on calorie restriction, periodic fasting and other hormesis.

There is no doubt that both calorie restriction and periodic fasting prolongs the life of many short–lived animals - worms, flies, mice, rats, hamsters, etc. Moreover, it prolongs significantly – it comes to a 50% increase in the pancreas:

And if you start from early childhood and feed only every other day, you can prolong life by 83% in general (most likely due to slowing down sexual development, which usually triggers the aging process): Effects of intermittent feeding upon growth and life span in rats // Gerontology, 1982.

However, similar effects on long-lived animals have not yet been observed. It would be unethical to starve people from infancy, but there were experiments on primates. I will analyze them in detail.

In total, three different long-term experiments have been conducted in history to assess the effect of calorie restriction on rhesus monkeys. The weakest study was conducted by the University of Maryland and published in 2004; there were only 8 starving macaques, and only three of them died at all. That didn't stop the researchers from fantasizing about what the survival curve in their study might look like. Yes, yes, they took it and drew it:

The fantasy curve predicted a good increase in median life expectancy by 20%, but, as further research showed, the fantasies were not destined to come true.

But the other two studies were quite large – several dozen monkeys in each.

The first study, known as the NIA study, was conducted in the nursery of the American Scientific Agency (NIH Animal Center) under the auspices of the American National Institute on Aging (NIA). It started in 1987.

The second, known as the UW study, was conducted by the University of Wisconsin at the Wisconsin National Primate Research Center. It began in 1989.

The most important thing to know about these studies is that in none of them did fasting prolong the life of primates by more than 5%. Five percent. Even if the macaques started to starve from the age of five, that is, quite early.

The best review article on both studies was published in January 2017 in Nature Communications: Mattison et al., Caloric restriction improves health and survival of rhesus monkeys.

Although it is rather promisingly titled, the results in it, as I have already said, are very modest:

As can be seen from the survival curves, there is no significant difference in pancreas between starving and non-starving groups. Moreover, in the NIA study, starving macaques often lived less than those who did not starve.

By the way, there is one oddity – three years earlier, the same group of authors (mainly from Wisconsin) published much more optimistic results on the Wisconsin study (UW study): Colman et al., Caloric restriction reduces age-related and all-cause mortality in rhesus monkeys.

True, in that study, the authors decided to divide the “age-dependent” mortality and mortality from all causes (they do not disclose the criteria for age-dependent causes of mortality in the article), but even the mortality from all causes in their starving group was slightly lower than in their article from 2017. Here are the survival curves:

And if we compare the curves of 2014 and 2017, they are slightly different:

For example, control individuals older than 30 years disappeared from the 2014 schedule in 2017. But when divided into males and females, it becomes noticeable that females have a large volatility in the effect of starvation (they die faster, then slower than control), and males have practically no effect.

By the way, it is worth noting that there was a slight difference in the diets of the control groups between the studies – in the NIA study, the monkeys were not allowed to overeat, and in the UW study they were given to eat “from the belly”:

But in any case, the fact that starving macaques, who for many years received 30% below the daily calorie allowance, lived quite a bit longer than their counterparts on various diets (or even less), personally suggests to me that there is no point in fasting.

At the same time, overeating, of course, is not worth it, since this life can already be reduced (sugar in general is evil, diabetes and Alzheimer's from it!), but you also do not need to torment yourself with starvation for the mythical 5 years of life.

And to extend life radically, you need to turn off the aging program. Without it, starve, don't starve, don't, don't, but you'll die anyway. Roy Walford and Savely Kramarov are witnesses to this.

Portal "Eternal youth" http://vechnayamolodost.ru  26.05.2017