Good nutrition will prevent 95% of all diseases.
— Linus Pauling
Anyone interested in the nutrition of dogs and cats has heard of it; the Maillard reaction.
But what is it and why is it being talked about?
The Maillard reaction was discovered in 1912 by Louis-Camille Maillard.
It is a spontaneous non-enzymatic reaction between sugars and proteins that occurs when food is heated. This reaction creates the crust on our bread and on the butter cake. We, and our pets, like the taste created by this reaction and therefore it is often used in the production of food to improve the taste of products.
This sounds like it’s a good thing but…….
on the other side of the coin, this reaction results in the formation of Maillard reaction products. For example, the formation of 5-hydroxymethylfurfural and acrylamide, which are both carcinogens. And the formation of “advanced glycation end products” or AGEs.
AGEs are normally also formed in the body, we call these endogenous AGEs and these accumulate in the body during aging. Both dietary AGEs and endogenous AGEs contribute to the total amount of AGE in a body.
Studies imply that dietary AGEs that contribute to the overall pool of AGE play a role in aging and the pathogenesis of disease.
Some effects of AGEs on the body:
– Structural changes of intermolecular and intramolecular connections of tissue proteins causing changes in properties and functions of these proteins.
– Activation of cellular communication pathways by binding to receptors or by directional activation that produces reactive oxygen radicals. Receptors of AGEs are called RAGE and these can be found on many cells in the body. Activation of RAGE through the binding of AGE results in chronic inflammation seen in many diseases in humans and dogs.
– They affect the microbiome in the gut.
– They negatively affect the epithelial barriers.
– They cause stimulation of the immune system which can lead to diseases.
In humans, AGEs have been shown to play a role in aging and in the pathogenesis of chronic diseases such as:
-Diabetes
– Overweight and metabolic syndrome
– Osteoarthritis
-Hernia
– Neurodegeneration
-Heart disease
– Renal failure
-Alzheimer ‘s
– Asthma
-Cancer
The high temperatures used in the production of animal feed facilitate the formation of AGEs. Ultra-processed foods contain higher levels of AGE and when eaten they result in higher plasma levels and excretion in the urine.
The Maillard reaction also takes place in our (processed) food. But we generally eat varied with both fresh and (hopefully not too much) processed food. Many dogs and cats receive only processed food such as kibble and cans throughout their lives and often eat the same food throughout their lives.
Van Rooijen et al (2014) showed that the average daily intake of Maillard products (MRP) in dogs is 122 times and in cats 38 times higher than in humans.
In 2016, van Rooijen et al showed that in cats increased uptake of MRP resulted in an increased amount of MRP in the urine. This study showed that MRP that are eaten are also absorbed and excreted through the kidneys.
Elevated levels of AGEs in tissues were found in older dogs with Diabetes Mellitus, cataracts, osteoarthritis, neurodegeneration, vascular dysfunction and atherosclerosis.
AGEs in the urine of dogs that ate ultra-processed food were 2 to 3 times higher than in dogs that ate raw minimal processed food (Palaseweenun 2020).
In cats, MRPs were associated with a reduced amount of taurine that was reversible with antibiotics. The researchers suggested that MRP affects the microbiome, creating a microbiome that breaks down more taurine. Taurine is an important essential amino acid for cats (Kim et al 1996).
There is a lot of evidence that processed food for dogs and cats contains higher amounts of Maillard reaction products and that these have a negative effect on the health of our pets.
So, should we be worried about that? I think so!
And it’s one of the reasons more and more pet owners are switching to fresh food with minimal or no processing.
Kim, S.W. et al (1996) Maillard reaction products in purified diets induce taurine depletion in cats which is reversed by antibiotics. J Nutr 126(1): 195-201
Van Rooijen, C. et al (2014) Quantification of Maillard reaction products in commercially available pet foods. J Agric Food Chem 62(35): 8883-8891
Van Rooijen, C. et al (2016) Urinary excretion of dietary Maillard reaction products in healthy adult female cats. J AnimSci 94(1), 185-195
Palaseweenun, P. et al (2020) Urinary excretion of advanced glycation end products in dogs and cats. J Anim Physiol Anim Nutr 105(1): 149-156
