Dietary supplements, aging and animals. How are they all connected?
Let's talk a little about aging and the hype that scientists and popularizers of science create around this topic. There are many different hypotheses explaining human aging. In each of them, one or more biological mechanisms are brought to the top of the hierarchy, which are called key and with which researchers propose to make some changes to slow down or prevent the processes of physiological aging. Thus, a number of researchers believe that age-related changes can be associated with the depletion of NAD + (nicotine-amine-dadenide-di-nucleotide). NAD + is a coenzyme of vitamin B3. It plays an important role in many biological processes, participating in energy metabolism and with age its amount gradually decreases, which is why scientists and popularizers of science pay close attention to it. To increase the production of NAD +, many researchers are trying to suppress the enzyme NADase (CD38), which causes depletion of NAD +, and are also trying to combine NAD + increasing drugs with senolytics. Senolytics are substances that specifically kill old cells. I'll write about them separately sometime.
Now, closer to the topic. Katherine E. Simon et al. in the article “A randomized, controlled clinical trial demonstrates improved owner-assessed cognitive function in senior dogs receiving a senolytic and NAD+ precursor combination” (2024) conducted an experiment in which they tried to increase the production of NAD+ in 62 elderly dogs of different breeds.
A small digression. In scientific circles, there is a gradual rethinking of laboratory models for studying aging and age-related diseases. In a number of works, one can already trace a trend when domestic animals are used as such laboratory models, not worms-rats-mice, citing their closeness to people.
So, the authors of this paper conducted a blinded, randomized, controlled trial of an anti-aging supplement that, in theory, should affect two signs of aging in older dogs: decreased mobility and cognitive function. Decline in cognitive function was assessed using the CCDR scale, and physical activity was assessed using a special collar. The researchers gave the dogs the senolytic LY-D6 and the NAD+ precursor LY-D2 (both commercial substances) to try to at least slow down the aging rate. Of course, the authors managed to achieve significant results, but I wrote this post not to advertise their mixture, but for another reason.
There is a certain class of food supplement manufacturers that follow hype more than science: hype allows them to confuse customers, allowing the manufacturer to take substances that cost next to nothing and sell them at a big markup.
I think the most disturbing thing about the publicly available information about Leap Years for dogs (here referred to as LY-D6/2) is that they don't tell consumers the exact ingredients in the product. They claim it's some kind of vitamin B3 derivative to boost NAD+ levels and some kind of plant extract with senolytic activity (likely fisetin or quercetin), both of which have received a lot of attention from scientists and science writers in recent years.
Moreover, it can be stated unequivocally that pharmacological increase of NAD+ level is probably less effective than physical exercise. In addition, the actual physiological effect of senolytics is most often very weak or not noticeable at all.
Given that Leap Years doesn't tell us what extract they use or how high the dose is, there's little to say about the prospects of the supplement strategy up front. It's not the most ethical behavior on the part of this organization, to say the least.
This example of scientific work is just one of many where science is used as an advertising platform. Be careful when reading catchy science popularization headlines and try to perceive everything through the prism of skepticism. In this world, you can’t trust anyone’s word, not even yourself.
Author: Misha Ivanov
