Small Molecules that Predict Dog Mortality also Forecast Human Lifespan, Study Shows

The same molecules that predict mortality in dogs do so in humans, according to a study published today in The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences.  The finding adds to a growing body of evidence that “dogs are the closest representation of human aging that anybody’s ever found,” said Ben Harrison, PhD, a senior scientist at the University of Washington School of Medicine and lead author on the paper.

The study is part of the Dog Aging Project, which began in 2020 and has enrolled 51,000 dogs and counting. Nearly 1,000 are part of the precision cohort, from which the researchers collect additional data, including whole genome sequences and annual biological samples such as blood, hair, urine, and feces. A quarter of the dogs have died since the project began, and the researchers can now begin to investigate why those dogs died while others survived.

This study is focused on whether mortality in dogs can be predicted using the levels of metabolites — small molecules that are the structural and functional components of life, including amino acids, nucleic acids, lipids, sugars, and vitamins.

The researchers chose to study metabolites because humans and dogs have similar sets of them.

“These are fundamental building blocks, and they’re deeply evolutionarily preserved,” said Daniel Promislow, PhD, FGSA, senior scientist and scientific advisor at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University and the paper’s senior author.

The investigators identified which blood-based metabolites were associated with the mortality of dogs in the precision cohort. Then they reviewed human studies and compared which metabolites were associated with the mortality of humans in those studies.

The metabolites predicted mortality in the precision cohort well. And the same metabolites that predicted mortality in dogs did so in humans.

“It was shocking,” said Harrison.

These findings demonstrate the value of using dogs as a model to study human aging, the researchers said. Dogs and humans live in similar environments, get similar diseases, and have similar healthcare systems. By establishing parallel associations of metabolites and mortality, the researchers can study potential interventions for both dogs and humans.

In this case, the researchers discovered an association in dogs that was known in humans. In the future, they can use dogs to study trends that aren’t known in humans and then check whether those trends are also supported in humans.

And because dogs age much faster than humans, Promislow said, “We can learn lessons from dogs almost 10 times more quickly than from humans about aging.”

This work received funding support from the National Institute on Aging, the Dog Aging Institute, the Glenn Foundation for Medical Research, and the WoodNext Foundation.

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The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences is a peer-reviewed publication of the Gerontological Society of America (GSA), which was founded in 1945 and is the nation’s oldest and largest interdisciplinary organization focused on aging. It serves more than 6,000 members in over 50 countries. GSA’s vision, meaningful lives as we age, is supported by its mission to foster excellence, innovation, and collaboration to advance aging research, education, practice, and policy. GSA is home to the National Academy on an Aging Society (a nonpartisan public policy institute) and the National Center to Reframe Aging.