Extending life is not the same as slowing down aging, and Nature questions three anti-aging treatments

In a new study, German scientists delved into three treatments
widely believed to slow down the aging process.
However, through tests in mice, they found that the putative effects of these therapies on aging were essentially ineffective
.

Dr.
Dan Ehninger, from the German Research Centre for Neurodegenerative Diseases (DZNE), the study's initiator, concludes: "You can't regulate the ageing clock in the body with a simple switch – at least not with the treatment we
studyed.
The team developed a new analytical method that can measure the effects
of various methods on the aging process.

The results of the study have now been published in
the journal Nature Communications.
Professor Martin Hrabě de Angelis of the Helmholtz Center in Munich, Germany, explains: "We selected three regulatory factors for intervention, and many experts believe that these methods can delay aging
.
”

The first is intermittent fasting, in which fewer calories are consumed
.
The second therapy targets the central node of cellular metabolism (mTOR), which is also targeted by the so-called "anti-aging drug" rapamycin
.
The third interferes with the growth hormone signaling pathway (GHRHR).

Similar treatments are also used by humans, but their efficacy in aging has not been fully proven
.

For these evaluations in mice, scientists have come up with new answers
to the question of how aging is measured.
Dan Ehninger explains: "In recent decades, many researchers have used longevity as an indirect measure
of aging.
"For example, how old do mice live? How to extend its lifespan?

"It's often thought that if mice live longer, they age more slowly
.
But the problem is that, just like other organisms, mice don't die from general aging, but from specific diseases," Ehninger said
.
For example, up to 90 percent of mice die in old age from tumors
that form in their bodies.
"So if you look at the entire genome and look for the factors that make mice live longer, you'll find a lot of genes that inhibit tumor development, not necessarily genes
that play a universal role in aging.
"

So in their new study, the scientists chose an approach that doesn't emphasize longevity, instead focusing on a comprehensive investigation of age-related changes in various bodily functions
.
"You can think of it as a complete health survey," Martin Hrabě de Angelis said
.
"The results of the health check cover hundreds of factors
in multiple areas of physiology.
"

They analyzed and compared three treatments purported to slow aging: How much does each parameter typically change at a particular stage of life? When mice received one of these treatments, did the parameters change more slowly? This study design allows precise determination of whether the natural aging process can be slowed down and the deterioration of important physiological functions can be slowed
.

The findings were clear: Although the researchers were able to identify older mice that looked younger than their actual age, it was clear that "this effect was not due to delayed aging, but to age-independent factors," Dan Ehninger said
.
"A treatment that had produced effects in young mice prior to age-dependent changes in health indicators proves that these effects are generalized health-promoting effects rather than targeting aging
mechanisms.
"

For now, the research team has set their sights on the next goal: they are ready to study other treatments
that some experts believe can slow aging.
The researchers hope that this new approach will provide a more holistic picture
of the various therapies and their effects.

Original search

Xie, K.
, Fuchs, H.
, Scifo, E.
et al.
Deep phenotyping and lifetime trajectories reveal limited effects of longevity regulators on the aging process in C57BL/6J mice.
Nat Commun 13, 6830 (2022).
https://doi.
org/10.
1038/s41467-022-34515-y