The kind of routine annual visit behind the blood work this study drew on
Nenad StojkovicCC BY 2.0
Illustrative: a veterinary checkup, not one of the 937 dogs actually enrolled in the Dog Aging Project's Precision Cohort, which relies on annual blood draws rather than a stethoscope exam.
The Same Blood Molecules That Predict How Long Your Dog Lives Also Predict How Long You Do
Every so often a study lands that is genuinely fun to read and rigorous at the same time, and this is one of those. Researchers with the Dog Aging Project measured thousands of blood metabolites in nearly a thousand pet dogs and asked a simple question: which ones predict dying sooner, and which predict living longer? Then they checked the answer against five large human studies, and the same molecules showed up carrying the same risk in both species.
- Researchers measured thousands of blood metabolites in 937 pet dogs and asked which ones predicted dying sooner or later, then checked the answer against five large published human mortality studies.
- The same molecules carried the same directional risk in both species, with correlations between zero point four six and zero point seven four across every comparison.
- Higher levels of pseudouridine, N2,N2 dimethylguanosine and homocitrulline tracked with dying sooner, while higher deoxycarnitine and homoarginine tracked with dying later, in both dogs and people.
- The lead researcher is explicit that none of this identifies anything to take. These are markers, not levers, and the paper itself is roughly a year old despite this week's coverage.
What the researchers actually did
The team drew on the Precision Cohort of the Dog Aging Project, 937 deeply studied pet dogs with annual blood draws and detailed owner reported life history. Instead of testing one molecule at a time, they analyzed thousands of metabolites together, looking for a pattern lead veterinarian Kate Creevy calls a metabolic fingerprint. They then compared the hazard ratios for individual metabolites in dogs against the same molecules across five large published human all cause mortality studies. The correlation held up strongly and significantly across every single comparison, with Pearson correlation values between zero point four six and zero point seven four.
The molecules that showed up in both species
Three molecules tracked with a shorter life in both dogs and people when levels were higher: pseudouridine, N2,N2 dimethylguanosine, and homocitrulline. Two tracked with a longer life when levels were higher: deoxycarnitine and homoarginine. The researchers used death itself as the outcome they tracked, on purpose. As Creevy put it, death is an easy outcome to understand, whereas other features of aging health are a bit more nuanced. That choice is part of what makes the finding so clean. There is no ambiguity about what happened to a dog or a person in this dataset.
Why the researchers keep pumping the brakes
This is the part of the story I actually want you to read past the headline. Homoarginine and deoxycarnitine, the two protective molecules, are both things you can buy as supplements right now. It would be easy, and wrong, to read this study as a hint to go supplement either one. Creevy is unusually direct about this. Those biomarkers do not necessarily cause an outcome, she said. When we find a biomarker associated with sooner or later mortality, we do not know that it is causing it. Nothing in this paper tested giving any dog or person more of either molecule. The finding is a correlation across two species, not a lever anyone has actually pulled.
Honest caveat
This is an observational, correlational study from start to finish. Nothing was randomized and nothing was given to any dog or person to test cause and effect, the researchers only measured what was already in the blood and compared it to what happened later. The comparison is also across species and across five differently designed human studies, so a shared statistical pattern does not prove shared biology underneath it. The paper itself is not new. Texas A&M and ScienceDaily surfaced it again on August 29, but the journal version sits in the April 2026 issue of the Journals of Gerontology and the preprint dates back to August 2025, roughly a year before this week's coverage. The full text of the paper was not read directly for this piece, only the journal abstract record and the university's own release. And the dog cohort is made up of owner enrolled pet dogs in the United States, which is not a random sample of dogs generally.
What this means for you
The honest takeaway here is not a supplement, it is a sentence. These blood markers describe risk, they do not cause it, and nobody, including the researchers who found them, is ready to say otherwise. If you want a genuinely evidence backed takeaway from this study, it is Creevy's own closing advice, and it is not a new one: keep a healthy diet, stay at a healthy body weight, and protect mobility and cognitive health, for yourself and for your dog. As she put it, what is good for us is probably good for them. That is a quieter answer than a headline about a mortality molecule, and it also happens to be the one this research actually supports.
Primary sources
- Harrison BR, Akey JM, Snyder Mackler N, Raftery D, Creevy KE, Promislow DEL. Dogs and humans share biomarkers of mortality. The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences, 2026;81(4):glaf279.
- Preprint: Dogs and humans share biomarkers of mortality, bioRxiv, August 20, 2025.
- Dogs may hold surprising clues to human longevity, Texas A&M University via ScienceDaily, August 29, 2026.
Common questions
Should I give my dog or myself homoarginine or deoxycarnitine supplements based on this study?
No. The study found that higher natural levels of these molecules in the blood were associated with living longer in both dogs and people, but nothing here tested giving either molecule as a supplement. The lead researcher is explicit that a biomarker associated with an outcome is not the same as something that causes it.
Is this a new study?
Not really. It resurfaced in the news on August 29, 2026, but the paper sits in the April 2026 issue of the Journals of Gerontology and the preprint was posted back in August 2025, so the actual research is roughly a year old.
What does this actually prove about aging?
It shows that the same blood metabolites track mortality risk in a similar direction in both dogs and people, which is a genuinely interesting piece of comparative biology. It does not prove that any of those molecules cause aging or death, and the researchers say so directly. It is a correlation across two species, not a mechanism.
Stay Curious.
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