//Aging thesis

You and your dog share similarities in your blood: Exploring markers of aging

by James McMahon
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Our poster presenting our aging biomarker study results. Loyal Senior Scientist James McMahon presented these results at Keystone Symposia: Molecular Basis of Healthy Aging, discussing our study on aging biomarkers in dogs, and how these findings relate to human aging.

The science of aging is particularly challenging, as it is a highly multifaceted disease. One puzzle we’re faced with at Loyal is searching for reliable ways to measure the biological effects of aging.

While everyone is familiar with chronological age, it’s not a perfect predictor of health status. Age affects every dog and person differently, and scientists make efforts to measure it in different ways.

For dogs, this means an eight-year-old Great Dane that leads a healthy lifestyle may not display the signs of aging of a five-year-old Great Dane, who is less active and has a greater number of age-related diseases. For humans, a 70-year-old that leads a healthy lifestyle may display fewer measurable signs of aging than a 50-year-old who primarily eats an unbalanced diet and also has comorbidities like being overweight and having high blood pressure. And, much of this — despite lifestyle — is directly related to whether someone has a genetic predisposition to age-related disease. 

In order to better understand how aging changes the body over time in both dogs and humans, we need a way to measure aging. An aging biomarker is something present in cells or blood that can predict health status more reliably than chronological age.


What’s even more exciting is that aging biomarkers can be leveraged to assess the effectiveness of an intervention used to treat aging. 

As leaders at the forefront of aging science, Loyal has chosen to focus efforts on discovering what these biomarkers might be.


Graphical representation of age-related declines in RBC and T cell counts shared in dogs and humans from Figure 1.1 in Loyal’s Keystone Symposium poster presentation “Aging Biomarkers: Dogs as a Transitional Species to Study Naturally Occurring Aging”

The Loyal team conducted two studies to evaluate potential biomarkers in dogs. Both of these studies looked at the blood of old and young dogs to determine if any specific age-dependent changes could point to a potential biomarker. We found a number of markers at the cellular and protein levels that change in an age-dependent manner. 

One change we observed was a decline in total lymphocytes with age. Lymphocytes are a type of white blood cell that helps your body fight off disease. 

Similarly, we looked at red blood cell count, which we saw declined with age. Red blood cells are responsible for delivering oxygen to all of the cells and tissues in your body. 

We found that insulin levels increased with age. Insulin is a protein that lets the cells in your body take in sugar, and elevated insulin in blood is a hallmark of metabolic dysfunction. These studies revealed a number of age-related changes that could be a big first step towards discovering a biomarker of aging.

A graph representing how aging biomarkers change over time

Loyal is dedicated to studying aging in dogs to give them longer, healthier lives. We also believe that understanding aging in dogs can help us better understand aging in humans. Interestingly, the findings in age-related biomarkers that we observed through our studies have all been observed in humans as well. This supports the argument that aging in dogs is closely related to aging in humans. Bridging this gap brings us closer to reliably measuring the progression of aging and the effectiveness of aging interventions, which is good news for our four-legged and bipedal friends alike.

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Meet James — a Senior Scientist at Loyal who believes studying dogs will unlock our understanding of biological aging in humans. James’ scientific career began at Pfizer Inc., where his metabolism and immunology research contributed to programs dedicated to improving patients’ lives. 

Like most researchers, James was drawn to the sciences because he wanted to make a difference in the lives of others. The challenging and intellectually stimulating environment of working in research had James hooked early on. James says, “Science is just a bunch of puzzles, and we have the power to solve them”.