One of the more enlightening, and terrifying, books to come out in the last 5 years is Tom Nichols’ The Death of Expertise. In clear prose, with cogent argument and substantiating evidence, the author makes the case that the proliferation of misconceptions, delusions, and bizarrely wrong beliefs about the world in every domain, from science to politics, reflects powerful and pervasive elements of American culture. Access to accurate information is easier than ever, yet misinformation thrives. The problem is not that the truth isn’t available to us, it’s that we actively reject it. In Nichols’ words,
These are dangerous times. Never have so many people had so much access to so much knowledge and yet have been so resistant to learning anything.
[The real problem is] we’re proud of not knowing things. Americans have reached a point where ignorance, especially of anything related to public policy, is an actual virtue. To reject the advice of experts is to assert autonomy, a way for Americans to insulate their increasingly fragile egos from ever being told they’re wrong about anything…It is a new Declaration of Independence: No longer do we hold these truths to be self-evident, we hold all truths to be self-evident, even the ones that aren’t true. All things are knowable and every opinion on any subject is as good as any other.
This is a phenomenon I have wrestled with for many years in my efforts to promote science-based veterinary medicine. Giving people facts and evidence is not sufficient because, as Nichols says, “When feelings matter more than rationality or facts, education is a doomed enterprise.” Believers and promoters of pseudoscience in medicine are armored by feelings and conviction against any inconvenient facts or evidence. And the average pet owner is at a disadvantage since they can’t always judge the relative merits of scientific claims or data for themselves, and they are left deciding which source of information to trust or, in the worst case, simply choosing to believe the claim that best fits their pre-existing world view.
A recent survey of pet owners investigating attitudes about raw and commercial coked pet diets illustrates this death of expertise quite starkly.
Empert-Gallegos A, Hill S, Yam PS. Insights into dog owner perspectives on risks, benefits, and nutritional value of raw diets compared to commercial cooked diets. PeerJ. 2020;8:e10383. doi:10.7717/peerj.10383
The facts are clear and not seriously questioned by actual experts, including veterinary nutritionists and most mainstream veterinarians. Raw diets have no proven benefits and any claimed for them are based on pure anecdote or theory. Raw diets do, however, have clearly established risks, including causing potentially deadly food-borne illness and often being nutritionally inadequate. The evidence to support these facts can be found in the many posts I have written on this subject.
Unfortunately, these facts are inconvenient for people who choose to feed such diets, and their reaction to being confronted with them is simply to redefine themselves as the “real experts.” Among owners feeding conventional cooked diets, 78% felt their veterinarian had a high level of knowledge about nutrition (4 or 5 on a 5-point scale). In this age when anyone can declare themselves an expert based on an internet search or some other informal way of investigating a subject, 65% of owners feeding cooked diets rated themselves as highly knowledgeable about pet nutrition, at the same level of knowledge, in fact, as their veterinarian. It is pretty unlikely that a majority of these owners have degrees in animal health or have taken formal instruction in animal nutrition, so this is a pretty unreasonable assessment. But it gets worse.
Of the raw feeders, 86% declared themselves highly knowledgeable (4-5 out of 5) while only 45% of them credited their veterinarian with this level of expertise. Raw feeders are no more likely than other pet owners to have degrees in animal health or nutrition, but they do have stronger feelings about the subject and are more likely to have investigated web sites or books for the general public making nutrition claims. These owners, whose beliefs are the least consistent with the facts, have the greatest confidence in their own knowledge and the least confidence in the expertise of actual veterinary professionals. This is unlikely to lead to good feeding choices or the best outcomes for pets.
The irrationality behind this false sense of expertise is illustrated by other findings in this study. Raw feeders rated commercial and homemade raw diets as more nutritious and safer than commercial cooked diets, both beliefs inconsistent with the facts. These owners likely imagine they have some special knowledge or insight into the “real truth” about pet food that owners feeding cooked diets, or even veterinarians, lack. This insight was not evidence, however, in their free-text answers to questions about the reasons for feeding raw diets, which included many vague references to unproven health benefits and terms consistent with unscientific beliefs about nutrition, such as “natural,” “processed,” “chemicals” and so on.
These owners clearly believe strongly that raw diets are healthier than cooked diets, but the strength of this belief, and the confidence in their own expertise in the subject, are based on misinformation and falsehoods. As Mulder would say, “The Truth is Out There,” along with the evidence to support it. But truth and facts aren’t nearly as effective at generating belief as the vapid handwaving and passionate proselytizing of raw food advocates. Ultimately, if people choose belief and feelings over science and expertise, they can maintain any belief regardless of the facts. Raw feeding, like so many other alternative veterinary practices, is just one more illustration of this pervasive and malignant cultural problem.
I recently came across a video of someone feeding their dogs’ kibble, the brand was Purina and hills and everyone in the comments was losing their minds. Most were bashing these brands and talking about how bad they were and they were the worst of the worst diets. There were a few who were talking about how these brands are good and safe as they have research to back them up. One of the comments however that stood out to me was asking why these diets are good without the simple answer being “science”. It truly goes to show that people don’t really believe in science and that it’s the best way to prove something.
Along with that is the internet favorite of “your vet knows nothing about nutrition and is being paid off by big kibble only get nutrition advice from a veterinary nutritionist.” but then what will happen when they speak to a nutritionist who bases themselves around science-based evidence and doesn’t support their opinions? they are being paid off and truly know nothing, it’s really bizarre to me how those who are on this raw only bandwagon will only listen to those that share their same beliefs and anything else is false information. quite frankly believing that all veterinary nutritionists are the only ones that will agree with them thus prove their beliefs.
It seems that the University of Helsinki is coming up with some kind of support for raw diets, what do you think?
https://www.helsinki.fi/en/researchgroups/dogrisk-health-via-nutrition-epidemiology-and-cancer-detection-dogs/research-by-dogrisk#section-56398
Yes, this research group is composed of raw-foo advocates, and they have been trying to produce positive evidence for these diets for a while. I’ve written about the group a couple of times, and so far I see more bias and wishful thinking than reliable data coming from their work.
Thank you, skeptvet, for providing a never-ending list of new terms I can add to my list fighting pseudoscience. I’m especially fond of the new “raw-foo” term.
No, please, don’t edit anything. Seriously, some of us get a kick out of your editing skills – I’d love to see your next book contain a glossary of these priceless, useful and quite fitting vocabulary. 🙂
My impression of the entire subject of K9 nutrition is that there’s a lot that is unknown and discussion is polarized. I don’t doubt studies saying that harmful microorganisms appear in raw foods… but other harmful microorganisms show up in improperly handled dry biscuits. One vet I worked with said healthy dogs can handle Salmonella and other nasties… I don’t know if that’s true or where the limits are. Evolution as scavengers can be expected to have given dogs some defense against eating meat and bone that isn’t fresh.
What I’d like to see is systematic study of morbidities from raw feeding.
And what I’d really like to see is very long term feeding experiments that could address questions like diet and the incidence of cancer. But the expense would be prohibitive, and outcomes likely inconclusive because there are a lot of variables.
I agree that the evidence is limited, but it is limited in all directions. There is enough to show conclusively the risk of raw foods is greater than cooked foods. This isn’t, frankly, the least bit controversial, and it is why humans eat mostly cooked meat. Dogs don’t have any magical resistance to salmonella, and while they may get away with eating raw much of the time, the risk is still greater.
There is, however, zero evidence for any health benefits from raw, so the balance at this point is limited evidence of risk and zero evidence for benefits. It is an act of blind faith in theory or anecdote. to recommend or feed raw.
Long-term feeding studies would be the strongest evidence, but as you say they are expensive and logistically difficult. They also likely wouldn’t convince proponents of raw to give it up no matter what the evidence, as alternative approaches in medicine generally, and nutrition specifically, have proven very resistant to facts. The evidence against most anti-vaccine claims, for example, is enormous and robust, yet that movement keeps growing. So is it worth testing a dubious hypothesis for the sake of producing evidence that might or might not change practice? Open question, I guess.
I read a few blogs and want to comment on this idea that anecdotes should be dismissed as evidence. In health care fields, both clinical trials and case studies are valid methods of scientific inquiry and each method has its own pros and cons. Case studies are essentially in-depth examination of anecdotes, while quite some clinical studies started from a research question that resulted from an anecdote.
In addition, statistically significant results in clinical trial studies mean nothing when the research questions are not guided by logically sound theory or hypothesis. When you have big enough sample, you will certainly have statistically significant result no matter how ridiculous the hypothesis is from logic or common sense perspective. That’s how statistics works.
Going back to raw vs. commercial dry food question. Cats survive and evolve for thousand years on eating small preys fresh. Logically eating meats, organs and bones fresh is the most natural/optimal diet for cats, because they are able to survive the process of natural selection by eating fresh meats, organs, and bones and their body must have adapted to eating fresh meats, organs and bones. I have two cats and did notice evident positive changes in their energy level, coat and skin conditions after I switched them from commercial dry to raw food. and please do not lecture me anecdotes don’t count. I have a doctoral degree in a health care field and have done both clinical trials and case studies. I know what scientist research/evidences mean and do NOT appreciate unsolicited research design refresher class.
I also found it ironic that you insist on evidence based practice, yet easily dismiss the study done at University of Helsinki because they are so called “pro raw group”. Research design class 101, all researchers have their own values and no one is completely objective. Its arrogant and ignorant to question someone’s research results based on what you perceive of their values. Dismissing opposing evidence suggests potentially unchecked bias.By the way, how many feeding trial studies are supported by commercial pet food companies? How many scholarships or donations to vet schools are provided by commercial pet food companies? When you question the validity of the study at University of Helsinki because of perceived pro raw bias, should you also question the validity of feeding trial studies of commercial dry food for the potential conflict of interest?
You make valid points about the nature of case reports/series and statistical significance,e but they don’t support your appeal to nature argument, which is a straightforward and misinformed fallacy, nor the implied claim that your individual experience with such diets somehow shifts the balance of evidence in favor of these diets. Anecdotes, including organized case reports, serve only to generate hypotheses, not to validate them.
As for the Helsini study, I don’t reject the findings on the basis of the authors’ biases, I am simply pointing them out as a factor to be considered. My objections to their conclusions are that they do not follow from the studies, which lack the kind of rigor necessary to compensate for investigator bias (e.g. this survey-based report).
As far as industry bias in feeding studies and other research, it is absolutey, real and I absolutely do question it all the time. However, if you are engaging in a bit of “whataboutism” and suggesting that the inherent funding bias in studies of commercial diets somehow strengthens the case for raw diets, that’s not a valid argument. Each must be evaluated independently on its own merits. Generally, the evidence for conventional diets is greater and quantity and quality than that for raw diets, as is, of course, the anecdotal evidence of tens of thousands of people who feed these diets, since that seems compelling to you.
Overall, there is small but clear evidence of risk from raw diets and nothing by hypotheses and anecdotes to support claims of benefits, which is the conclusion of my article.
I think that the risks of raw feeding outweigh the benefits but, there are a few valid, scientific points that are made that can still be fulfilled in commercially available food without the inherent risks of raw feeding.
1. Otto Warburg found in 1931 that many types of cancers feed off of glucose as their primary source of energy. In a few trials, it was found when rats were put in a state of ketosis where all the carb was removed the lung cancers shrunk in size. There were also two small studies done in 2013 finding similar results in cancer patients. There are many commercially available cooked and canned diets that are almost all meat contains little to no carbs. This is not the exact same as a keto diet with high fat but, an extremely high-fat diet would only be suitable for extreme working dogs to not gain weight and even then it would increase the risk of pancreatitis. This is the closest option that is healthy for modern canines.
2. The bioavailability of many man-made nutrients is not known well. This is not to say that commercially available AFFCO certified foods are unbalanced as dogs today are rarely malnourished unless their owners are negligent and are not feeding them an adequate amount. There were some researchers that isolated vitamins from natural substances and compared those to commonly used forms of supplements under a microscope and found that the structure of the vitamins in minerals was rather different. Although, just because the structure is different does not mean absorption is compromised or elevated. This solution to this concern, questionable if it is a reality, is to find a premade food that does not rely on man-made supplementation as the main means of nutrition.
There are a few problems with these seemingly reasonable arguments-
1. The extrapolation from lab studies, especially those done almost 100 years ago, is a tricky business. The relationship between simple sugars and both simple and complex carbohydrates in the diet and cancer risk/progression is a murky and ill-defined one. There are studies suggesting low-carb diets can have benefits in some situations. However, there is almost no evidence in dogs or cats showing such diets have meaningful effects in preventing or treating cancer. There is very little research in humans to support this idea. And low-carb diets are almost always unsustainable in the long term. The evidence for ketogenic diets in pets and for the general thesis that low-carb is healthier is very weak, so the leap you make from the theory to the use of low-carb diets int he real world is more a leap of faith than a reasonable step supported by rigorous science.
And the notion of what constitutes “low-carb” vs “high-carb” is also not well-defined. There is a huge range of micronutrient profiles in commercial dog foods, and the precise rations, much less specific sources, that would minimize cancer or other health risks have not been established. As we have seen with the grain-free diet fad, leaping to a dramatic change in feeding practices on the basis of extrapolation from pre-clinical studies or flimsy research evidence has risks.
2. I would like to see some evidence to support the claim that one can draw a meaningful distinction between the biologic effects of “natural” and synthetic micronutrients. Such claims are often made, but they mostly rely on the appeal to nature fallacy, not on real evidence. As you say, nutrient deficiencies are vanishingly rare with convention diets (and much more common with extreme alternative diets), so again claiming that pet owners should be wary of commercial diets with synthetic supplements is not likely to lead to better health when there is little reason to believe going “natural” is truly healthier.
As to Warburg effect:
https://respectfulinsolence.com/2016/08/22/did-the-experimental-cancer-drug-3-bromopyruvate-3-bp-cause-the-deaths-of-cancer-patients-at-a-german-alternative-medicine-clinic/
Dr Gorski has written numerous times about this, above is an example
Hi! I’m sure this has been covered elsewhere but unfortunately I was unable to find it through search. As a layperson, why does feces in dogs on some formulas/diets tend to be foul smelling or give some dogs excessive gas? From what I understand, volume seems to be because of more indigestible fiber which isn’t a bad thing; is that correct?
Volume is related to the amount of indigestible material, predominantly plant fiber. Fiber can have many effects on GI microbiome, fecal consistency, GI transit time, nutrient absorption, etc. It’s not really fair to say fiber is “good” or ‘bad,” because the type, amount, relationship to other ingredients, and many other factors are involved. In general, however, fiber often has beneficial effects on stool quality and health.
Of course, it can also stimulate growth of bacteria that produce methane and other malodorous compounds, so a foul smell may be related to fiber content and type, but again this may or may note indicate something of significance for health. In humans, for example, beans and cruciferous vegetables often stimulate production of lower GI gas and malodorous compounds, but these foods are generally benign or even beneficial for us.
each dog also has a unique GI physiology and microbial flora, and that can affect how they respond to specific ingredients in a diet, so a diet may make one dog gas and not another. There is always some trial-and-error to choosing a diet for any individual dog.
Hope this is helpful, even though there is n’t a single, simple answer to your question! 🙂