Is Cooking Your Dogs Food Bad?
Balanced raw diets can do amazing things for a dog's health and wellbeing but there are some dogs that don't do well on raw diets and need alternatives that are not dry food - there are also pet parents who simply do not want to feed raw for whatever reason.
However, like any passionate community, there are people within the fresh food community who can be more rigid in their thinking and perhaps a bit extremist who will absolutely not tolerate strangers on the internet feeding a cooked diet as bizarre as that sounds. What we aim to do on this information page is go through why feeding your dog a balanced cooked diet isn't going to destroy your dogs health & wellbeing. For those who need science to tell them it's ok (or get triggered by), we're also going to look at some studies that are relevant to the discussion. In the end, whether you feed your dog raw or cooked is up to you - you do you and let other people do them :)
A common statement we hear in the fresh food community is that cooking destroys/voids nutrients - now if this were the case, we would all be dead because we would have no nutrients to fuel our bodies.
Cooking changes the nutritional profile of a food, it does not void/destroy them.
Cooking does denature protein when cooked above 40 degrees Celsius but it does not change the amino acid sequence. People sometimes use denaturing as a reason not to cook their dog's food, yet they happily cook their own food without concern for denaturing.
So what is denaturing?
"Denaturation changes a protein’s shape, not its amino acid content, so denaturing protein by cooking doesn’t ordinarily lower its nutritional value. Cooking can, in fact, make food more nutritious particularly plant foods by making them more digestible - For example, cooking improves the nutritional value of rice, uncooked rice is quite indigestible." [4]
What are Amino Acids?
Amino acids are the building blocks of proteins. They are the molecules that all living things need to make protein. "Amino acids are required for the synthesis of body protein and other important nitrogen-containing compounds, such as creatine, peptide hormones, and some neurotransmitters."[6]
Denaturing is what makes protein more digestible
"When heated, proteins unwind from their tightly bound forms, losing their tertiary structures and secondary structures. Denatured proteins adopt a random coil configuration that makes proteins more digestible by increasing their susceptibility to proteolytic enzymes." [3]
What are Proteolytic Enzymes?
"Proteolytic enzymes (proteases) are enzymes that break down protein. These enzymes are made by animals (humans and dogs), plants, fungi, and bacteria".[5]
Cooking Starchy Plants
Cooking makes some nutrients in some plants more bioavailable i.e. starchy plants like potatoes and pumpkin. "Raw starch granules are semicrystalline mixtures of amylopectin and amylose plus trace amounts of protein and lipid. They are normally resistant to hydrolysis by salivary and pancreatic amylases."[1] "Cooking functions to predigest starches, improving their nutritional availability, with the extent of predigestion being dependent on the temperature of processing and the amount of water present"[2]
In simple terms, "cooking increases the ileal (the third part of the small intestine) digestibility of carbohydrates by gelatinizing starch, reducing the quantity reaching the colon"[7]
Cooking Eggs
The protein in cooked eggs is 180% more digestible than that of raw eggs. In fact, one study found that the human body could use 91% of the protein in cooked eggs, compared to only 51% in raw eggs. [8]
Nutrients that "may" be reduced through cooking
Although cooking improves digestion and the absorption of many nutrients, it "may" reduce levels of some vitamins and minerals.[9]
Water-soluble vitamins: vitamin C and the B vitamins — thiamine (B1), riboflavin (B2), niacin (B3), Pantothenic acid (B5), pyridoxine (B6), folic acid (B9), and cobalamin (B12)
Fat-soluble vitamins: vitamins A, D, E, and K
Minerals: primarily potassium, magnesium, sodium, and calcium
Why do we say "may"?
Because the cooking method matters. Water soluble vitamins are sensitive to heat so if you were to boil your broccoli for instance, you could lose up to 50% of its vitamin C component. However, if you pressure-cooked it, you could retain 90-95% of its nutrients.
There are various studies that look at this from different viewpoints, the one below, in particular, looked at the effect of cooking methods on the nutritional quality of selected vegetables in a specific city:"In comparison to raw, boiled, and microwave-cooked vegetables, those that are steam-cooked retain a higher percentage of β-carotene with the exception of carrots. Boiling vegetables led to the most substantial reduction in ascorbic acid content (from 9.83 % to 70.88 %), with spinach experiencing the greatest decline."[10]
Save the pot water
If you saved the water from the pot and used it over your dog's food, you'd be adding nutrients back into their diet, for instance, 100% of the minerals and up to 90% of the B vitamins lost during cooking are retained in the pot water. [11,12]
Omega-3
"While water-based cooking methods cause the greatest losses of water-soluble vitamins, they have very little effect on omega-3 fats".[9]
Digestibility of cooked fresh food diets vs kibble
I don't think we really needed a study to know what the outcome was going to be here......fresh food vs highly processed diets. "
"The apparent total tract digestibility of DM, protein, fat, nitrogen-free extract, and calories of the kibble diet were all significantly lower than any of the fresh diets".[13]
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Macronutrient digestibility of extruded (kibble), mildly cooked, and raw diets
A 2018 study found that "lightly cooked and raw diets tested were highly palatable, highly digestible, reduced blood triglycerides, maintained fecal quality and serum chemistry, and modified the fecal microbial community of healthy adult dogs." [14]
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[1] https://symposium.cshlp.org/content/74/427.long
[2] https://www.sciencedirect.com/science/article/abs/pii/S0733521000903503
[3] https://pubmed.ncbi.nlm.nih.gov/3036878/
[4] https://med.libretexts.org/Bookshelves/Nutrition/Science_Physiology_and_Nutrition_for_the_Nonscientist_(Morrill)/05%3A_Energy-Providing_Nutrients/5.07%3A_Protein#:~:text=Note%20that%20denaturation%20changes%20a,by%20making%20it%20more%20digestible.
[5] https://www.webmd.com/vitamins/ai/ingredientmono-1623/proteolytic-enzymes-proteases
[6]https://www.ncbi.nlm.nih.gov/books/NBK234922/#:~:text=Amino%20acids%20are%20required%20for,requirement%20is%20for%20amino%20acids.
[7] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6886678/#:~:text=Cooking%20increases%20the%20ileal%20digestibility,of%20amylolytic%20gut%20bacteria9.
[8] https://pubmed.ncbi.nlm.nih.gov/9772141/
[9] https://www.healthline.com/nutrition/cooking-nutrient-content#cooking-amp-nutrients
[10] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10660054/#:~:text=In%20comparison%20to%20raw%2C%20boiled,spinach%20experiencing%20the%20greatest%20decline.
[11] https://pubmed.ncbi.nlm.nih.gov/19650196/
[12] https://www.emerald.com/insight/content/doi/10.1108/NFS-11-2012-0123/full/html
[13] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8279163/?fbclid=IwZXh0bgNhZW0CMTAAAR1L2hPtHWTjpmfC0zZ3nDJe9M_yqcB-t2v0b7nV851va8qVLGkTNO354AU_aem_AZXBA0qv86cRsxg4dhO9GN4RzcNjU6InerW-M5hn0A8JGnEtEYDDnm-DUjVXqN78dizMEOYXyMVxn2KtHWwW3y0z
[14] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6127788/
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