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Kibble & Cancer | Raw Feeding Veterinary Society

Article from the Raw Feeding Veterinary Society, 2020 [read more...]


Food is fuel for the body. Few can challenge this. Unfortunately weak, biased and inconclusive research muddies the rest of nutrition science. We must, therefore, rely somewhat on logic and common sense to make sense of food and its effects on health. If we make observations of the world where a correlation between observations is apparent, we must, if we are seeking truth, realise that association does not always mean causation. For example, skid marks are found often on roads near car crashes. This is an association. It does not mean that skid marks cause traffic accidents. Our example is ridiculous to make a point. When you’re dealing with subtle food-body relationships, where causality might be attributable to any of hundreds of constituents of the edible material, it is easy to make mistakes and misinterpretations. Reputations are staked on nutritional ‘truths’. Large corporations offer enormous grants for the ‘right’ research, burying unflattering findings. Seeking ‘facts’ in nutrition is like stalking the Loch Ness monster. In this article, I look at some evidence of apparent links between food and cancer in humans and dogs and try to offer my thoughts. You may think differently.

Ultra-processed Food

The World Health Association and the World Cancer Research Fund concluded, in 2014, that ‘sugary drinks, energy-dense snacks and ‘fast food’ are key drivers of obesity, diabetes, cardiovascular diseases and some cancers’. Our dogs do not consume sweet drinks. They do, though, chomp an awful lot of high carbohydrate, energy-dense snacks and ‘fast food’. We give these nutritional products the emotive name, ‘Ultra-processed foods’ (UPFs).UPFs were defined in 2017 as, ‘Industrial formulations typically with five or more and usually many ingredients. Besides salt, sugar, oils, and fats, ingredients of ultra-processed foods include food substances not commonly used in culinary preparations, such as hydrolysed protein, modified starches, and hydrogenated or interesterified oils, and additives whose purpose is to imitate sensorial qualities of unprocessed or minimally processed foods and their culinary preparations or to disguise undesirable qualities of the final product, such as colorants, flavorings [sic], nonsugar sweeteners, emulsifiers, humectants, sequestrants, and firming, bulking, de-foaming, anticaking, and glazing agents’. Amongst all that industry jargon, I think it is quite easy to see what they are saying. UPFs are highly synthetic industrially manufactured creations, made up of many non-food elements, formulated to ‘disguise undesirable qualities of the final product’. Caitlin Scott, writing in the MIT Global Environmental Politics journal in 2018, suggests, ‘These foods are designed to be ‘convenient, eaten-on-the-go, hyper-palatable and appealing to consumers, and, most importantly, the most profitable segment of Big Food companies’ portfolios because of these foods ‘low-cost ingredients’.

Is My Dog Food UPF?

Yes. If you are feeding tins or dry kibble, very likely. Here are the ingredients of a dried kibble with UPF ingredients underlined: Dehydrated poultry protein, rice, maise, vegetable protein isolate*, wheat, animal fats, vegetable fibres, hydrolysed animal proteins, beet pulp, fish oil, minerals, soya oil, fructo-oligo-saccharides (0.34%), psyllium husks and seeds, hydrolysed yeast (source of manno-oligo-saccharides), hydrolysed crustaceans (source of glucosamine), borage oil (0.1%), yeasts extracts (source of beta glucans), marigold extract (source of lutein), hydrolysed cartilage (source of chondroitin). Vitamin A: 26500 IU, Vitamin D3: 700 IU, Vitamin E: 780 mg – E1 (Iron): 38 mg, E2 (Iodine): 3.8 mg, E4 (Copper): 12 mg, E5 (Manganese): 49 mg, E6 (Zinc): 130 mg, E8 (Selenium): 0.08 mg – Technological additives: Clinoptilolite of sedimentary origin: 10 g – Sensory additives: Yucca extract: 125 mg – Preservatives – Antioxidants. * LIP: protein selected for its very high digestibility. And from a randomly chosen, very well known brand of tinned dog food: Meat and Animal Derivatives 41% (Including 4% Chicken), Cereals, Minerals, Derivatives of Vegetable Origin (0.5% Dried Beet Pulp), Oils and Fats (0.5% Sunflower Oil), Vegetable Protein Extracts. Extraordinarily, this popular product seems to contain no actual food, only processed ingredients.

How Strong is the UPF Link to Cancer?

Well, the UK’s NHS recently quoted a British Medical Journal (BMJ) study of UPFs and cancer in humans, saying, ‘each 10% increase of UPF in the diet was linked to a 12% increase in risk of any cancer, and an 11% risk of breast cancer in older women.’ Mammary gland carcinomasare the most common tumours in unspayed female dogs. Cancer is the leading cause of death in dogs, with at least half of all animals over the age of 10 years old succumbing. Twice as many dogs die of cancer than humans in whom the incidence is one in four individuals. Unlike most humans, though, the majority of dogs, unfortunately, eat exclusively tinned or dry kibbled UPFs every single day for their entire lives. I think it likely that their industrial synthetic diets play a leading role in this horrible canine cancer statistic.

How Can UPF Cause Cancer?

The researchers in the BMJ study said there are “several hypotheses” that could explain the link. The first one relates to ‘the generally poorer nutritional quality of diets rich in UPFs’. Secondly, they mention that UPFs contain a ‘wide range of additives such as nanoscale particles of Titanium dioxide used as a whitening agent or in the packaging in contact with food and drinks to provide better texture and antimicrobial properties’. They go on to point out that high-temperature processing of food can induce the formation of known carcinogens like acrylamides. These deadly substances are only found in trace quantities, the manufacturers would argue. Maybe, but unwitting pet owners feed them to their precious companions for life with every meal and treat. Finally, the researchers highlight Bisphenol A, a contaminant that migrates from plastic packaging. Bisphenol A is a hormone disruptor that the European Chemical Agency has judged a ‘substance of very high concern’.


It seems very hard, given the evidence, to deny a powerful link between UPFs, pet food and cancer. I advocate the feeding of fresh raw food to dogs and have done for 25 years. A terrifying pile of proof now annually appears to support this simple, logical and commonsense approach to reduce the chance of our pets dying of cancer.


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