The benefit and necessity of grain-free pet food have come under scrutiny in recent years due to an FDA investigation due to a potential association with a canine heart disease known as dilated cardiomyopathy (DCM). As a result of this potential association, many have been told there is no scientific evidence to support the use of grain-free foods in canines and felines, or that these foods do not provide any benefit over grain-inclusive foods. For the most part, grain-free refers to kibble, although some have also categorized various canned, freeze-dried, and raw diets under the ‘grain-free’ umbrella. But are these claims accurate? Let’s find out:
Grain-free foods don’t provide benefits?
The pet food industry’s switch to grain-free was not fueled by a problem with the grains themselves or grain allergies like most believe. The largest pet food recalls in history was due to melamine and cyanuric acid contamination of ingredients coming from China. The short version of the 2007 recall is that wheat gluten and rice protein were intentionally combined with melamine for its high nitrogen content. Higher amounts of nitrogen can cause the protein content of an ingredient to test higher than it actually is. Since cyanuric acid was present, and the combination of melamine and cyanuric acid is likely the reason the recall was so deadly – not the melamine on its own. This series of events fueled the consumer trend of wanting grain-free pet food.
Another major factor absent from the discussion on grain-free vs. grain inclusive diets for people – and pets – is the contamination of grains with herbicides, pesticides, mycotoxins, and fertilizers. This has become an increasingly large concern since the mid-’90s in both the human and animal food supply. Numerous peer-reviewed articles are detailing the disruption many of these agricultural contaminants have on normal gut bacteria function.1,2 In fact, available literature suggests that humans are becoming increasingly intolerant to grain and grain products for exactly these reasons (e.g. wheat & gluten sensitivity & celiac disease in humans).
We are learning that disruption of vital gut bacteria balance can have devastating effects on the health of the host, including diabetes, obesity, autoimmune disease, cancers, GI issues, and even DCM.3–5 Could the contamination of grains in pet food be one reason why many pets experience improvement of various issues with the change from grain-inclusive to grain-free? Could be.
Ultimately the phrase ‘there is no evidence to support the use of grain-free foods’ doesn’t mean there is not a benefit. It simply means that we have a major gap in research into companion animal nutrition and that we easily forget our recent history. On the contrary, we don’t have evidence to support that feeding grains to canines or felines are any more healthful than feeding grain-free diets. Evidence only shows that it meets minimal (known) nutritional standards, not that pets thrive on these processed diets. In short, canine and feline nutrition fields are far behind the knowledge we have in livestock and human nutrition.
Are ALL grain-free foods the same?
Many veterinarians and pet owners automatically lump grain-free cans, fresh food, raw food, and freeze-dried products as ‘grain-free’. While this is technically correct – there are stark differences that make these foods different from their kibble counterparts.
Regardless of whether we are feeding grain-free or not, we need to consider the high temps kibble and canned foods are heated to during the manufacturing process. This high heat creates Maillard Reaction Products (MRP) which is the name for a series of reactions that is the product of sugar (carbohydrate) and protein when heated. These are also known as AGE’s or Advanced Glycation End Products.
MRP’s are responsible for the nutrient loss and associated with diseases like diabetes, cardiovascular disease, kidney disease, loss of cognitive function, allergies, periodontal disease, and chronic inflammation.6–12 This can mean things like arthritis, skin, and ear issues, an old injury that keeps resurfacing, bloating, IBS, etc. Also, there is a large amount of research to suggest that they are carcinogenic and accelerate aging.13,14
- Heterocyclic amines are MRPs from cooking protein that increases with elevated cooking temperature. This phenomenon is more pronounced in meat than fish – and these increase with temperature and dryness of meat or meat products15.
- Acrylamides are a chemical that forms naturally from starchy foods during high-temperature cooking. According to the European Food Safety Authority evidence from animal studies shows that acrylamides are genotoxic and carcinogenic: they damage DNA and cause cancer. And since we know so little about animal nutrition is it possible that much of the disease we’re seeing – including DCM – has at least something to do with the MRP’s that are in dry and/or canned pet food? Is it a coincidence that freeze-dried, fresh, and raw options do not have as many associated issues as their processed counterparts? Maybe.
Allergic to Grains? Probably Not (sorry, not sorry)
Pet food can be made of everything from rendered unfit foods for human consumption to ingredients that are 100% organic and probably better than the food we feed ourselves. I’m not necessarily here to split hairs on ingredients and in the types of ingredients that are in our pet’s food. Because is it these ingredients that are causing the problem? Or is it something else? – These are the questions that the experts seem to avoid entirely. When a dog experiences issues related to food, we are quick as a society to turn over the bag and blame an ingredient or set of ingredients. However, those ingredients as listed are likely not the problem – rather the quality, processing agents, AGE’s and contamination of these ingredients (e.g. herbicides, pesticides, etc.); something you will never find listed on a label.
More Important: Nutrient Availability & Digestibility
The digestibility of food is altered as it is processed, mixed with other ingredients, and heated. That said, canned and kibble foods by definition will have varying levels of nutrient availability and digestibility than their lesser processed counterparts. The ingredients (or set of ingredients) that make up a food could be the most nutrient-dense food available – but if they are not digestible by the cat or dog then those ingredients are irrelevant. In short, this means that it is important to ask your pet food company for their digestibility and nutrient analysis to determine if their food is adequate for your pet. Learn more about what questions to ask and why here.
About the author: Nicole Cammack
Nicci is the owner of award-winning NorthPoint Pets & Company, in Connecticut. She is also the Founder & CEO of Undogmatic Inc. Her undergraduate and graduate education includes biology, chemistry, business, and nutrition. She has worked in the pharmaceutical industry on multiple R&D projects and has had the privilege to learn from leading international figures in the human and pet health industry. She regularly lectures at national conferences, including federal, state, and municipal K9 events. Her current research involves identifying pathogenic risk factors and transmission among raw fed pets through a comprehensive worldwide survey.
- Van Bruggen AHC, He MM, Shin K, et al. Environmental and health effects of the herbicide glyphosate. Sci Total Environ. 2018;616-617:255-268. doi:10.1016/j.scitotenv.2017.10.309
- Aitbali Y, Ba-M’hamed S, Elhidar N, Nafis A, Soraa N, Bennis M. Glyphosate based- herbicide exposure affects gut microbiota, anxiety and depression-like behaviors in mice. Neurotoxicol Teratol. 2018;67:44-49. doi:10.1016/j.ntt.2018.04.002
- DeGruttola AK, Low D, Mizoguchi A, Mizoguchi E. Current Understanding of Dysbiosis in Disease in Human and Animal Models. Inflamm Bowel Dis. 2016;22(5):1137-1150. doi:10.1097/MIB.0000000000000750
- Galland L. The Gut Microbiome and the Brain. J Med Food. 2014;17(12):1261-1272. doi:10.1089/jmf.2014.7000
- Yoshida N, Yamashita T, Hirata K. Gut Microbiome and Cardiovascular Diseases. Diseases. 2018;6(3). doi:10.3390/diseases6030056
- Jandeleit-Dahm K, Cooper ME. The Role of AGEs in Cardiovascular Disease. doi:info:doi/10.2174/138161208784139684
- Pion PD, Kittleson MD, Thomas WP, Skiles ML, Rogers QR. Clinical findings in cats with dilated cardiomyopathy and relationship of findings to taurine deficiency. J Am Vet Med Assoc. 1992;201(2):267-274.
- DCM: add taurine to grain-free dog foods, say scientists. Accessed May 15, 2019. https://www.petfoodindustry.com/articles/8162-dcm-add-taurine-to-grain-free-dog-foods-say-scientists?v=preview
- DACVIM CDSBM. Breed-specific variations of cardiomyopathy in dogs. dvm360.com. Accessed May 15, 2019. https://veterinarynews.dvm360.com/breed-specific-variations-cardiomyopathy-dogs
- Dilated Cardiomyopathy in Dogs. vca_corporate. Accessed May 15, 2019. vcahospitals.com/know-your-pet/dilated-cardiomyopathy-dcm-in-dogs–indepth
- Medicine C for V. FDA Investigation into Potential Link between Certain Diets and Canine Dilated Cardiomyopathy. FDA. Published online June 27, 2019. Accessed June 29, 2019. https://www.fda.gov/animal-veterinary/news-events/fda-investigation-potential-link-between-certain-diets-and-canine-dilated-cardiomyopathy
- Freeman LM, Stern JA, Fries R, Adin DB, Rush JE. Diet-associated dilated cardiomyopathy in dogs: what do we know? J Am Vet Med Assoc. 2018;253(11):1390-1394. doi:10.2460/javma.253.11.1390
- Prasad C, Imrhan V, Marotta F, Juma S, Vijayagopal P. Lifestyle and Advanced Glycation End Products (AGEs) Burden: Its Relevance to Healthy Aging. Aging Dis. 2014;5(3):212-217. doi:10.14336/AD.2014.0500212
- Turner DP. Advanced glycation end-products: a biological consequence of lifestyle contributing to cancer disparity. Cancer Res. 2015;75(10):1925-1929. doi:10.1158/0008-5472.CAN-15-0169
- Jägerstad M, Skog K, Arvidsson P, Solyakov A. Chemistry, formation and occurrence of genotoxic heterocyclic amines identified in model systems and cooked foods. Z Für Leb -Forsch A. 1998;207(6):419-427. doi:10.1007/s002170050355