Researchers from the German Center for Neurodegenerative Diseases (DZNE) and from Helmholtz Munich/the German Center for Diabetes Research (DZD) carried out an in-depth examination of treatment methods which, according to conventional wisdom, can slow down the aging process. Experiments carried out on animals proved that these treatments were, however, to a large extent ineffective with regard to their supposed influence on aging.
For their interventions, the researchers chose three regulators which are assumed by many experts to slow down aging. The approaches examined included intermittent fasting, the release of growth hormone, and influencing a central hub of cellular metabolism (mTOR), which is also the goal of the supposed “anti-aging drug” rapamycin.
New methods for measuring aging
Researchers have up until now assumed that mice age more slowly if they live longer. The problem is, however, that – like many other organisms – mice do not die from general frailty due to old age but rather from very particular illnesses. Up to 90 percent of mice die from tumors that form in their bodies in advanced age. For their study, the scientists therefore chose an approach which did not focus on lifespan but rather comprised a comprehensive examination of age-related changes in a wide range of bodily functions.
Looking at various stages of life, they examined and compared mice who had been treated with the three anti-aging methods: To what extent do the parameters usually change, and at which stage of life? And: Do they change more slowly when the mice have been treated with one of the three treatment methods? This study design makes it possible to establish with pinpoint accuracy whether the natural aging process can be held up, and with it the deterioration of bodily functions.
The results were very clear: The researchers were indeed able to establish that there are some individual cases in which old mice look younger that they actually are – but this effect did not come about through a slowing down of the aging process but rather through factors that were independent of age. “The fact that a treatment takes effect even in young mice – before signs of aging start to appear – proves that these are compensatory effects that promote good health in general and that they are not having an effect on aging mechanisms,” says Dan Ehninger, from DZNE.
The teams from DZNE and the Helmholtz Diabetes Center have now set themselves a new goal: They want to examine further treatment methods which experts believe can slow down the aging process. The new method used for the study creates a more comprehensive picture of possible treatment methods and their effectiveness.
Kan Xie,…., Martin Hrabě de Angelis & Dan Ehninger et al.: Deep phenotyping and lifetime trajectories reveal limited effects of longevity regulators on the aging process in C57BL/6J mice. Nature Communications volume 13, Article number: 6830 (2022). DOI: doi.org/10.1038/s41467-022-34515-y