I have written about the issue of homemade pet diets here several times (1, 2, 3, 4). They are appealing to some owners because they appear more “natural” than commercial dry or canned diets, which is supposed to imply they are better for pets. And, of course, many proponents of alternative medicine make hysterical and unsupported accusations about the dangers of conventional pet diets.
People also equate conventional commercial pet food with what is typically called “processed food,” though they are entirely different things. Human snack foods and other processed foods are laden with excessive sugar, salt and fat and generally nutritionally poor. Commercial pet foods, if properly formulated and manufactured, are nutritionally balanced to a greater degree than our haphazard diet of whatever looks appealing in the moment, even when we the packaged junk foods are avoided.
Homemade diets can be perfectly healthy, and there are circumstances in which a diet formulated for the specific needs of a particular pet is better than any commercially available diet. And fresh food is certainly attractive to many pets. But the dramatic claims of health benefits made for them are entirely unproven, and the existing research suggests most recipes for homemade diets, even those promoted by veterinarians, are not appropriately balanced nutritionally and not ideal for long-term health. I encourage anyone interested in preparing food at home for their pets to consult with a board-certified veterinary nutritionist for guidance.
I recently ran across a press release from a company which appears to be trying to cash in on fears of commercial pet food and the appeal of homemade diets in order to sell—you guessed it, their commercial pet food. Reminiscent of the “just like homemade” marketing approach often used to sell packaged foods for people, JustFoodForDogs makes heavy use of terms like “scientific” and “evidence” in their marketing to suggest that dry commercial diets and the ingredients they contain are unsafe and that their packaged frozen cooked diets are better. While these diets appear to meet all the same standards for balanced nutrition of other commercial diets, including AAFCO feeding trial tests, the evidence offered for their superiority is so far scant.
One unpublished study funded by the company and run by one of their veterinarians is referred to in their press release as “groundbreaking” and “game changing.” Science by press release is always a bad sign (anybody remember “cold fusion?”), but the presentation of the study is clearly designed to maximize its marketing value without providing any of the information that would be needed to determine if the methods were really appropriate.
Twenty-one dogs of unspecified breeds were fed some of the company’s diets (the details are not reported) and basic bloodwork and exams were conducted at the beginning of feeding the diet and again at 6 months and twelve months. No control group, no blinding, no pre-specified outcomes or hypotheses, no reported accounting for repeated measures or multiple comparisons in the statistical analysis, no discussion of any other aspects of the dogs health or environment, and overall none of the hallmarks of an actual controlled clinical study. All of this would be fine of the purpose were merely to explore the effects of the diet and generate hypotheses. But the company clearly intends to present these results as earthshattering, paradigm-shifting research that (coincidentally?) favors their product.
And after setting up everything with no apparent effort to control for the obvious risk of bias, what were the reported results? One kind of blood protein, globulins, went up (by how much isn’t disclosed). Some kinds of white blood cell numbers increased (again, by how much isn’t disclosed, but the numbers were apparently still within the range of normal). And one measure of red blood cells increased, though another did not.
Given the comparisons of many different values with no explicit reason and no reported use of statistical methods to control for making them, it is almost guaranteed some values would change to a degree judged “statistically significant.” This is not the same thing as medically significant, and there is no evidence these changes had any clinical relevance, especially with no control group for comparison. But the company promotes the results as showing their foods “could benefit immune health” and that if the purported trends in the blood values continue for the animals’ lifetimes “we may see a decrease in chronic diseases such as cancer, renal failure, kidney disease, inflammatory bowel disease, dental disease, etc.”These results certainly don’t support anything even approaching such claims.
The hypothesis that fresh foods could have health advantages over extruded kibble or commercial diets is not an unreasonable one, and I am open to the possibility this might be true. But this is not something we can simply assume without evidence, and that evidence does not yet exist. Furthermore, the claims made about the dangers of conventional commercial diets are rarely supported by evidence either, whereas there is abundant scientific research and real-world experience showing that pets can live long, health lives on these foods.
If the folks behind this company genuinely believe their claims about health and nutrition, and I have no reason to think they don’t, then they should make an effort to design and conduct properly controlled scientific research to evaluate their hypotheses. But they do a disservice to pets and pet owners when they perform “studies” clearly designed with marketing rather than science in mind, hype the results to an extreme degree, and then use this as a marketing strategy to promote their own products.