The Science of AGEs and what heat-processed kibble is doing inside your dog’s body

Is this a question most dog owners never think to ask? Not “Is my dog getting enough protein?” or “Are there vegetables in this?” — those questions are on the bag, answered in marketing language designed to reassure. The question that rarely gets asked is a more unsettling one: what did the manufacturing process do to this food before it reached the bowl or what were the process used to make this?

It turns out the answer matters enormously. And a growing body of research suggests that one consequence of high-heat food processing — the formation of compounds called Advanced Glycation End Products — may be quietly accelerating the ageing process in dogs who eat kibble every single day of their lives.

WHAT ARE ADVANCED GLYCATION END PRODUCTS?

Advanced Glycation End Products, mercifully shortened to AGEs, are toxic compounds formed when proteins and sugars react together under high heat. The process is called glycation, and it happens spontaneously whenever food is cooked at intense temperatures — which is precisely what occurs during the manufacture of dry kibble.

The production of extruded dry dog food involves exposing raw ingredients to extremely high heat and pressure in a process called extrusion. The result is those familiar pellets. The collateral damage, from a biochemical standpoint, is a significant load of AGEs baked into every bite.

AGEs are not new to science. In human medicine, they have been studied for decades in relation to diabetes, cardiovascular disease, kidney damage, and accelerated ageing. The mechanism is well understood: AGEs bind to specific receptors in the body (called RAGE — Receptor for Advanced Glycation End Products), triggering chronic low-grade inflammation and oxidative stress. Over time, this damages tissues, stiffens blood vessels, and accelerates cellular ageing in ways that are invisible day-to-day but cumulative over a lifetime.

The question researchers have more recently started asking is: what happens when dogs consume a diet chronically high in AGEs — every meal, every day, for years?

WHAT THE SCIENCE SAYS

In 2025, a significant metabolomic study led by Dr. Heather Huson at Cornell University investigated exactly this question. The research — among the first of its kind to directly measure circulating AGE levels in dogs across different diet types — produced findings that should give every kibble-fed dog owner pause.

Dogs switched to a fresh, minimally processed diet showed measurably lower concentrations of specific AGEs in their bloodstream after just one month. The compounds that fell most notably — N6-carboxymethyllysine and pyrraline — are well-established markers of dietary AGE exposure, and both are significantly elevated in dogs eating high-heat-processed food.

One month. Not a year of nutritional overhaul. A single month of eating real, unprocessed food produced a detectable shift in the dog’s metabolic profile.

The implications are significant. If chronic dietary AGE exposure drives the same inflammatory and oxidative mechanisms in dogs that it does in humans — and the biology suggests it does — then the cumulative effect of eating kibble over years may be contributing to the very conditions that shorten our dogs’ lives: inflammatory disease, organ deterioration, and accelerated cellular ageing.

This sits alongside evidence from the Dog Aging Project, one of the largest longitudinal studies of canine health ever conducted. Analysing data from over 27,000 dogs across different diet types, researchers found meaningful associations between diet and owner-reported health conditions — with dogs on conventional processed diets showing higher rates of several inflammatory and chronic health conditions than those on fresh or raw alternatives.

WHY KIBBLE IS PARTICULARLY HIGH IN AGEs

Not all cooking creates AGEs equally. A lightly steamed vegetable creates far fewer than a biscuit baked at high temperature. The more intense the heat, the more prolonged the process, and the more sugar and protein are present together, the greater the AGE load.

Dry kibble scores poorly on every one of these factors. Extrusion involves temperatures that can exceed 150°C under pressure, applied to a mixture that is rich in both protein and starchy carbohydrates (used as a binding agent). The result is a product with an AGE content that researchers have found to be dramatically higher than minimally processed or raw alternatives.

There is also the matter of bioavailability. AGEs in food are partially absorbed through the gut wall into the bloodstream — estimates in human research suggest around 10% of ingested AGEs are absorbed and enter systemic circulation. In a dog eating the same kibble twice a day, 365 days a year, the daily top-up to circulating AGE levels is continuous, unrelenting, and — until recently — almost entirely invisible to owners.

Raw food like our Wild Pheasant, by contrast, contains AGEs at a fraction of the level found in heat-processed alternatives. Ingredients that have not been subjected to high-temperature manufacturing retain their natural biochemical integrity. The proteins remain proteins. The fats remain fats. The sugars don’t react with the amino acids under industrial heat, because there is no industrial heat. What goes into the bowl is, to a far greater degree, what nature produced.

WHAT THIS MEANS FOR YOUR DOG

It is worth being clear about what the science is and isn’t saying. AGEs are not a poison in any acute sense. A dog fed kibble is not in immediate danger. But chronic, low-level exposure to compounds that drive inflammation and oxidative stress — compounds that the dog’s body must constantly work to manage and excrete — is a different matter. It is the difference between a single large insult and a quiet, daily drain on the body’s resources.

The Cornell study’s finding that just one month of fresh feeding measurably reduced circulating AGEs is, in that light, genuinely encouraging. It suggests the body can respond relatively quickly when the dietary source of AGEs is removed. The burden is not fixed — it is a reflection of what is currently in the bowl.

For Iris, our eight-year-old Labrador, this research has always felt particularly personal. Watching an older dog move into the later years of her life, it becomes impossible not to think about what we can do — practically, daily — to protect her body from the things that accelerate decline. The answer, increasingly, is the same one the science keeps pointing back to: feed real food. Food that hasn’t been transformed by industrial heat into something the body has to work harder to handle.

A NOTE FROM WOLFIE

Every batch of Wolfie is handcrafted from fresh, seasonal ingredients from us at Baronscourt Estate — wild pheasant, wild venison, wild mixed game — minimally processed and never subjected to the high-heat extrusion that generates dietary AGEs. We don’t do it that way because it’s a marketing angle. We do it because it’s the right way to feed a dog you love.

The science is catching up to what instinct has always suggested to us. Real food, close to its natural state, is what a dog’s body recognises and uses. Less processed. Less inflammatory. More life.

Woldie

REFERENCES

1. Huson, H.J. et al. (2025). Metabolomic analysis of fresh vs. heat-processed dog food: circulating AGE concentrations in dogs after one month dietary intervention. Cornell University / The Farmer’s Dog. https://www.prnewswire.com/news-releases/new-study-from-the-farmers-dog-reveals-fresh-human-grade-dog-food-may-promote-healthier-aging-in-senior-dogs-302588450.html

2. Dog Aging Project (2025). Association between diet type and owner-reported health conditions — 27,478 dogs. PMC12010193. https://pmc.ncbi.nlm.nih.gov/articles/PMC12010193/

3. Vlassara, H. & Uribarri, J. (2014). Advanced glycation end products (AGE) and diabetes: cause, effect, or both? Current Diabetes Reports, 14(1), 453. https://pubmed.ncbi.nlm.nih.gov/24292971/4. Semba, R.D. et al. (2010). Dietary accumulation of advanced glycation end products and their role in aging. The Journal of