Cancer Diet Redux: When is the "Cancer Diet" not recommended?

When should the "cancer diet" not be fed to veterinary cancer patients?

We should begin by determining when the "cancer diet" *should* be fed to cancer patients. It is fairly universally recognized now that cancer cells exhibit increased glucose utilization compared to normal cells, and this metabolic defect is the basis for research to determine whether lowering glucose concentrations (by limiting simple carbohydrates in the diet) can improve cancer survival.

Clinical proof that a low carbohydrate diet is clinically beneficial remains a little lean. A single clinical trial in dogs suggested that a low carbohydrate, high fat diet containing fish oil and arginine accelerated time to remission in lymphoma patients and may extend the disease-free interval. Every cancer is different, and test tube studies on human cancer cells suggest that different cancers respond differently to various nutritional profiles in their media.

While a few million dollars has likely been spent on canine research in this area, billions have been spent in human nutritional oncology. And we still don't have definitive proof as to the best diet for cancer patients. In dogs and the cats, the usual recommendation is to feed a low carb diet simply because there is a physiologic rationale for it. In people, it is recommended that they eat the diet that helps prevent cancer - low in animal fat, high in vegetables, full of variety - and people should continue to get exercise. And while there is plenty of evidence in people that excess weight *loss* during cancer treatment worsens the prognosis, there is now emerging evidence that being obese while undergoing cancer treatment also worsens prognosis.

The dietary key to influencing cancer proliferation is that the diet be high in fat - tumor cells are unable to use fat as an energy source, whereas dogs and cats can do this very efficiently. So the "low carb diet" for cancer patients is usually quite high in meat (which contains a lot of fat), low in starches and sugars, and contains added fat. A logical conclusion is that for pets with cancer only - no pancreatitis, no advanced renal disease, no obesity, etc - a low carb, moderate protein, high fat food makes sense. But for patients with these other disorders, the diet can not only worsen the prognosis but even make death from the other disease more imminent than death from cancer.

I'd like to focus here on managing obesity in a cancer patient. Here's the thing - obesity leads to hyperglycemia - high blood glucose - and insulin resistance. This hyperglycemia is much more persistent than the elevated glucose load that occurs after any meal of any composition. In addition, surgery, radiation and chemotherapy can cause changes in endocrine functions that could increase the likelihood of development of metabolic syndrome (de Haas, 2010).Cancer itself is commonly associated with hyperglycemia (Heber, 2006). Whether this persistent hyperglycemia and insulin resistance leads to worse outcomes in veterinary patients is unknown, but glycemic control is routinely recommended in human patients when hyperglycemia is identified (Heber, 2006). This is both to control episodes of infection (made more likely through the use of immunesuppressive therapies) but also to prevent progression to metabolic syndrome and diabetes which is a risk factor for the development of other cancers.

Obesity is also an 'inflammatory disease', as is cancer. Fat is now considered an organ that releases excess infl ammatory cytokines, such as tumor-necrosis-factor-α (TNFα) and interleukin 6 (IL-6) (de Haas, 2010). These cytokines are considered growth factors that can activate genes that control angiogenesis, invasion and metastasis of cancer cells.

The obese cancer patient then gets a double dose of simple sugar in the blood, and more inflammatory chemicals already being produced by the tumor itself. These patients just have to be 'sicker' - whether or not they show it - than patients of normal weight. Hence the new evidence that some obese human cancer patients have worse outcomes than people of normal weight. This has been shown most frequently in breast, prostate and colon cancer (Ramos 2010, Sinicrope 2010, Komaru 2010, Siegel 2010, de Azambuja 2010, Lange 2008, Nitori 2009). Additionally, some recent trials suggest that overweight patients undergoing controlled weight loss during cancer treatment experienced improved prognosis (Freedland 2009).

A diet that is low in simple carbohydrates and higher in meat protein will be fairly calorie-dense, depending on the proportion of meat to other ingredients. A homemade version of the low carb diet can be made to resemble an Atkins-style diet. This can work for weight loss in some patients but not necessarily for others, because meat comes with fat - even the lower fat meats. If I formulate a diet for an obese patient, I use a lower fat protein, such as tofu, often along with a small amount of a starch, and plenty of vegetables. These proportions are customized to the individual dog, and the vitamin/mineral levels are also changed as needed. The starch and sugar content is still quite low, and weight loss can be facilitated.

I see many people who request the 'cancer diet' for their pet with cancer, and a few who refuse to believe that it is inappropriate for their particular pet. We have an increasing number of studies in people to suggest that customizing the diet for an obese patient improves survival, and only 1 study in dogs suggesting that the high fat low carb diet makes a difference in survival. The veterinary oncologist that investigated the low carbohydrate diet for veterinary cancer patients has repeatedly written "no one diet is right for every cancer patient". You can't believe that his research is right 100% of the time but that this opinion of his is wrong 100% of the time.


References

de Azambuja E, McCaskill-Stevens W, Francis P, Quinaux E, Crown JP, Vicente M, Giuliani R, Nordenskjöld B, Gutiérez J, Andersson M, Vila MM, Jakesz R, Demol J, Dewar J, Santoro A, Lluch A, Olsen S, Gelber RD, Di Leo A, Piccart-Gebhart M.The effect of body mass index on overall and disease-free survival in node-positive breast cancer patients treated with docetaxel and doxorubicin-containing adjuvant chemotherapy: the experience of the BIG 02-98 trial. Breast Cancer Res Treat. 2010 Jan;119(1):145-53.

de Haas EC, Oosting SF, Lefrandt JD, Wolffenbuttel BH, Sleijfer DT, Gietema JA. The metabolic syndrome in cancer survivors. Lancet Oncol. 2010 Feb;11(2):193-203.

Freedland SJ, Aronson WJ. Dietary intervention strategies to modulate prostate cancer risk and prognosis. Curr Opin Urol. 2009 May;19(3):263-7.

Heber, D. Assessing Endocrine Effects of Cancer and Ectopic Hormone Syndromes. Nutritional oncology. Elsevier, St Louis, 2006; p. 695

Komaru A, Kamiya N, Suzuki H, Endo T, Takano M, Yano M, Kawamura K, Imamoto T, Ichikawa T. Implications of body mass index in Japanese patients with prostate cancer who had undergone radical prostatectomy. Jpn J Clin Oncol. 2010 Apr;40(4):353-9. Epub 2010 Jan 10.

Lange BJ, Smith FO, Feusner J, Barnard DR, Dinndorf P, Feig S, Heerema NA, Arndt C, Arceci RJ, Seibel N, Weiman M, Dusenbery K, Shannon K, Luna-Fineman S, Gerbing RB, Alonzo TA. Outcomes in CCG-2961, a children's oncology group phase 3 trial for untreated pediatric acute myeloid leukemia: a report from the children's oncology group. Blood. 2008 Feb 1;111(3):1044-53. Epub 2007 Nov 13.

Nitori N, Hasegawa H, Ishii Y, Endo T, Kitagawa Y. Impact of visceral obesity on short-term outcome after laparoscopic surgery for colorectal cancer: a single Japanese center study. Surg Laparosc Endosc Percutan Tech. 2009 Aug;19(4):324-7.

Ramos Chaves M, Boléo-Tomé C, Monteiro-Grillo I, Camilo M, Ravasco P. The diversity of nutritional status in cancer: new insights. The Oncologist 2010; 15(5):523 -530

Siegel EM, Ulrich CM, Poole EM, Holmes RS, Jacobsen PB, Shibata D. The effects of obesity and obesity-related conditions on colorectacl cancer prognosis. Cancer Control 2010; 17(1):52-57.

Sinicrope FA, Foster NR, Sargent DJ, O'Connell MJ, Rankin C. Obesity is an independent prognostic variable in colon cancer survivors. Clin Cancer Res. 2010 Mar 15;16(6):1884-93. Epub 2010 Mar 9.

How to choose a pet food

As a nutritionist and integrative practitioner, I’m asked almost every day what pet food I recommend. It’s an interesting thought – that I recommend one pet food.

At the same time, my nutrition training has led me to question authority. While the holistic folks like to vilify the big over the counter and prescription brands of food, my training has shown me that they employ some of the best – and some of the worst- company philosophies. And this is what I’m about today – choosing a company, and not a food.

Before I tell you what personal philosophies drive *my* company choices, I’ll paint a picture of the problem for you.

Over the past decade, I’ve had occasion to ask for more detailed information about a food based on my patients’ needs. You see, the guaranteed analysis on the food label provides only the barest guide as to the nutrient profile of the food. And while I care about *ingredients*, I also care that my patients are being provided with essential *nutrients* they require for continued normal functioning.

I’ve needed to know if the protein content was able to meet the minimum needs for animals who required caloric restriction of a high fat diet. I’ve needed to know if amino acid profiles were adequate in a vegetarian diet with a suspicious ingredient listing. And I’ve been disturbed by the digital equivalent of a blank stare I got when asking for this information from some of the most popular makers of ‘holistic’ and ‘natural’ diets. The ones you are feeding your pets right now, and the ones your local pet store employee is pushing as new and improved.

Here is a sampling of the problems I’ve encountered when trying to obtain nutrition information from the ‘holistic’ pet food companies:

1. Labels with egregious mistakes showing either inaccurate information or terrible formulating errors.
2. Company leaders who do not know what a nutrient profile* is, much less how to provide one to a nutritionist.
3. Refusal by a company to provide nutrient profiles, stating that it is proprietary information (ok, but you will never hear me recommending your diet, especially if it is a certain new vegetarian diet). Honestly, the largest companies post their profiles on the web – do you really think it has cut into their profits?
4. Diets (raw and processed) that are not complete or balanced when nutrient profiles are submitted to detailed analysis.
5. A company that refuses to deal fairly with a veterinarian who discovers a major problem with its food.
6. Companies that refuse to provide the names or credentials of their food formulators
7. Naïve representatives making dangerous claims because they don’t understand the simplest feed concepts, such as dry matter conversions
8. Company heads that misuse their meager knowledge of nutritional biochemistry and microbiology to make unfounded health claims and spread misinformation across the web.
9. Advertising claims that tout health benefits that were disproven years before.
10. Companies that for decades refuse to acknowledge new information and adjust their formulas, simply because people continue to buy their foods.

So how do you choose a pet food?

You don’t- you choose a company. So here are my criteria for recommending a food manufacturer:

1. The company needs a track record. Even if it’s your best friend whom you consider knowledgeable, the company she owns or recommends needs to prove its ability to produce consistently safe formulations, hold onto the best employees, and is using profits to improve (and not just expand) the company.
2. There should be a board certified veterinary nutritionist on staff. Not just a veterinarian – a veterinary nutritionist. I’ve seen some very questionable formulations even from companies owned by veterinarians. The only way the formulations can improve over time is if a nutritionist is constantly feeding updated knowledge into those formulations.
3. The company philosophy fits with my clients’ standards** and my patients needs.

Once we settle on a few companies, I have these additional recommendations for my clients:

1. Choose foods that carry an AAFCO feeding claim to be complete and balanced for the appropriate life stage of your pet. Some smaller pet food companies do not produce balanced diets, and others produce pure meat diets “intended for supplemental or intermittent feeding”. Nutritional deficiencies could result if any of these are fed long term.
2. Rotate between various companies (i.e. use various flavors , but also from different companies)
3. Avoid exotic ingredients like duck, rabbit, emu, pheasant, and venison. They aren’t necessary for healthy pets and we may need for them to be completely new to your pet when diagnosing or treating certain conditions later. There is plenty of variety to be had with chicken, lamb, beef, pork, turkey, fish, egg and vegetarian foods. It’s also easier to find organic versions of these ingredients.
4. Feed your dog veggies and fruits as snacks or to beef up the amount of food in his bowl. It is may help prevent cancer, and they are low in fat. Avoid grapes, raisins and onions, which can be toxic to pets. Choose all colors, including carrots, broccoli, cauliflower, bell peppers, squash, apples, melon, berries, etc). Feeding more meats and starches is rarely necessarily, especially if you are already feeding a premium or Paleolithic diet.
5. Don’t buy large bags of food for small animals- food should be used up within a month, especially if it is stabilized with natural preservatives instead of chemical preservatives.
6. Avoid dry foods in cats and if your cat is currently eating dry, make an appointment to talk to a nutritionist about why this may no longer be recommended and how to switch stubborn kitties to canned or homemade food. At the very least, for heavens’ sake, do not leave free choice dry food down – for dogs OR cats. Most just get fat on it!

Seems like a lot to remember, but here is the simple version: feed balanced foods, with healthy ingredients, from different companies. Give veggies and fruits instead of junky treats, and maintain a lean body weight. If you prefer homemade, get the recipe balanced, and stick to the plan. And of course, check in with your vet for regular physical and biochemical exams to find emerging problems early.

Notes

*A nutrient profile shows the levels or concentrations of all essential nutrients in a food . This profile is compared to the nutrient requirements of a dog or cat to determine whether it is marginal, deficient, or replete for a particular life stage or condition.

**Philosophies and standards are unique to each pet owner. Some won’t tolerate commercial diets at all, while others don’t care if they are commercial as long as they are (pick one – raw, natural, organic, made of human grade ingredients, etc). Some trust larger companies and care only that the correct *nutrients* are provided, while others don’t care about nutrients and consider *ingredients* most important, absolutely prohibiting by-products. A few clients believe that locally sourced ingredients are best (necessitating a homemade diet unless you happen to live near a company that uses ingredients local to *you*). If you really want to know, my philosophy necessitates a complete and balanced nutrient profile, identifiable ingredients (although by-products of some types are just fine with me considering the true natural diet of dogs and cats), a veterinary nutritionist on staff, and a company that balances the need for economy with the need to document the safety of their raw ingredients (usually requiring domestically sourced ingredients). The company should be transparent in its operations (some have allowed the WDJ editor to visit their plants, and some regularly invite veterinarians for tours, while others won’t answer phone calls). And of course, I think homemade diets are superior as long as they are balanced. I’ve seen some awful sick animals eating weird homemade recipes, and I’ve seen so many improve if we just balance while incorporating the owners’ preferences!

A corollary to discovering fraud: finding information on the web

A corollary to the problem above is that of how to evaluate pet-related information. Those who rely on the internet are particularly at risk. There are two main types of sites - noncommercial (such as that from teaching hospitals, government agencies and foundations) and commercial (generally someone who wants you to buy their product). In health care, it is best to avoid commercial sites if possible, but some do contain good information. It takes some training to recognize the difference. Here is what to look for:

1. Scientific references - these come from scientific journals such as the Annals of Internal Medicine, The Cochrane Database, the Journal of the American Veterinary Medical Association, the Journal of the International Veterinary Emergency and Critical Care Society, Journal of Nutrition, etc. Scientific references do not come from newspapers, Time magazine, or Cat Fancy.
2. The references and information should be relevant to your pet – test tube studies and those in laboratory mice are probably meaningless to a dog in the real world. Human studies are somewhat more useful, but dog studies are best. (And cats are a completely different issue because they are metabolically very different from humans, dogs, mice and most other species we can think of). Testimonials are not useful at all – they can be ignored!
3. The people who write articles and formulate nutritional supplements should be clearly identified, along with their training and credentials. Contact information should be easily available.
4. If information on the site seems extremely optimistic or promises to cure chronic and terminal illnesses, please refer back to #1 - 3.
5. If the site promotes and sells brand name products, refer back to #1-4.
6. If the ingredients and amounts are not available, avoid purchasing from the company. “Proprietary ingredients” are secret ingredients, and there is no way to tell whether they may be toxic to your pet.
7. If the site sells veterinary products, the company should be a member of the National Animal Supplement Council (www.nasc.cc), an industry group that insures high standards of quality control and maintains an adverse event reporting system. We do use human products for animals as well, but the dose should be recommended ONLY by a veterinarian familiar with the supplement, and not by the company if they employ no veterinarians.
8. The site should have links to other sites, and these links should provide multiple ‘points of view’ about the issue or condition. Beware of sites that link ONLY to other alternative medicine sites, or conversely, those that link only to quackbuster sites. Use these other sites to verify that the information you are gathering is fairly well accepted and not the opinion of one well spoken company representative or lone practitioner who only sees a few patients a year!
9. The site should clearly indicate when it was last updated. Medical information is generally old after only a year!

Finally, please do NOT assume that consumers and pet owners have access to the same information that veterinarians do. Our professional networks keep us informed of research before it is published, and of breaking news never seen in the newspapers or internet. Please verify your information with your veterinarian, or just skip all of the work above, and ask her first!

I can recommend these websites to start your research:

1. Veterinary Partner (www.vspn.org) - database of in-depth articles on veterinary conditions and the conventional diagnostics and treatments recommended. Usually kept very well updated.
2. Healthnotes (http://www.pccnaturalmarkets.com/health/ and click on the link “Health Conditions A-Z” as well the links “Vitamins, Minerals and Herbs A-Z”). Information about human health conditions and the supplements commonly used for them.
3. The National Library of Medicine (www.pubmed.org). The scientific database of peer-reviewed journal articles published from about 1960-present. You can retrieve abstracts of the studies and occasionally, the full scientific article.

How to Identify and Avoid Phony Practitioners

How to Identify and Avoid Phony Practitioners

Seems like everyone who wants to can be a doctor these days, no schooling required. A dictionary definition of a doctoral degree is:
• any of several academic degrees of the highest rank, as the Ph.D. or Ed.D., awarded by universities and some colleges for completing advanced work in graduate school or a professional school
• an honorary degree conferring the title of doctor upon the recipient
• a degree awarded to a graduate of a school of medicine, dentistry, or veterinary science

It’s that second definition that is most troublesome, because it means that anyone can open up a virtual school and award doctoral degrees for whatever level of work – or dollars- they think sufficient.

The field of naturopathic medicine is shot through with such fraud. Only 16 states license naturopathic doctors. The licensing process requires graduation from a 4 year naturopathic school with virtually the same curriculum as that of a medical school, with natural treatments substituted for drugs and surgery.

These institutions have been accredited or are in candidate status for accreditation by one of the regional accrediting agencies approved by the US Department of Education. In addition, all of the naturopathic medicine programs of the member schools have been accredited (or are candidates for accreditation) by the Council on Naturopathic Medical Education (CNME).

On the other hand, the naturopathic schools that offer long distance education say that their courses are approved by the American Naturopathic Certification Board (ANCB). These graduates are not eligible for professional licenses. Strangely, the ANCB's website states "Due to ANCB's stringent application and certification requirements, ANCB is the certification organization preferred and recommended by the leading schools of Traditional Naturopathy, including Clayton College of Natural Health and Trinity College of Natural Health" [both are online diploma mills]. Does this seem a little incestuous?

Now naturopathy has come to veterinary medicine. One online diploma mill requires a “recognized Master's degree in a natural health field” to enter ‘doctoral’ programs offered there, but no definition of what this means. The accreditation for this school is through the American Association of Drugless Practitioners (Texas). That’s all.

We even need to worry about people making up certifications on their own. I once taught a course online on herbal medicine that was open to veterinarians and veterinary technicians. A technician, after finishing the course, granted herself a “Dip.Vet.Bot.Med” on her website, where she was offering animal health consultations. This was new to me as the instructor of the course. Presto – certified in herbal medicine after a 4 week introductory course!

So how do we judge the quality of the educational experience for practitioners of animal medicine? Let’s compare the curriculum and experience of the diploma mill to that of a veterinarian who is familiar with naturopathic principles:

Veterinary education (in the U.S.):
• Requires an undergraduate (college) degree from a university or college accredited by the US Department of Education, with a concentration on chemistry, biology and physics.
• 3 years of full time, in residence schooling that includes about 6 hours daily of didactic lectures, labs and contact with instructors who hold advanced degrees or certifications in their fields
• Required textbooks are comprehensive specialized reviews of medical science
• 1 year of full time clinical experience under direct supervision of faculty who are specialists in their fields
• Regular competency exams culminating in national and state board examinations that must be passed in order to obtain a license to practice.
• Further education on herbal medicine, acupuncture, homeopathy and other natural modalities requires well over 100 hours of study for certification each. A recent survey of 300 veterinarians who practice natural or integrative medicine revealed that 61% of veterinarians with at least 6 years of integrative practice experience have accumulated at least 250 classroom hours in integrative medicine. Of these practitioners, more than 30% have taken more than 500 hours of class room training.

Diploma mill doctoral degree:
• 200-300 hours (claimed) of self study
• Faculty - just a few of the school’s own graduates - available by phone or email
• Required textbooks are simple compilations for pet owners, typically available at your local book store
• Final exam is 3-5 questions, open book

Graduates holding a “VND” or “Doctor of Veterinary Naturopathy” degree have been taught that it is illegal for them to diagnose or prescribe in order to treat animal disease, so they position themselves as educators. Of course, the fact that they suggest treatment recommendations after learning symptoms, and the fact that they often sell just the natural remedies needed certainly could not be viewed as prescriptions (please know that I have on my most ironic smile right now). In addition, they make these recommendations without seeing the animal, which could vitally change the prescriber’s overall assessment. Yes, some veterinarians also do this, but most have medical records or direct communications from a veterinarian who has seen the animal, which solves that problem.

Any veterinarian understands the pet owner’s desire for second opinions and to have a team behind their pet’s medical care. But you can do better by your pet if you stock that team with professionals who have received comprehensive and well rounded veterinary and natural medicine education. Look for the initials below:

Veterinary degree: VMD, DVM, BVSc, MVB, VetMB or BVetMed, BVM&S or BVMS, Dr.Med.Vet
Natural medicine certifications (post graduate training offered only to veterinarians):
Acupuncture: CVA, FAAVA
Herbal Medicine: CVCH (Chinese herbal medicine), CVHM (Western herbal medicine)
Homeopathy: CVH, VetMFHom, CertIAVH
Chiropractic: cAVCA, IVCA, CVSMT
Physical therapy/rehabilitation: CCRT, CCRP
Chinese massage (tui na): CVTP

Nonveterinarians holding the “VND degree” and those who follow them may well wonder why we can’t all just get along. The argument would be that they offer only information that is complementary to that of veterinarians, and that they are only educating pet owners on how to better care for their pets. The situation feels to me much like medical practice in the US in the early 1900s. There were many private medical schools and many different educational experiences, and people had many different types of practitioners to choose from.

In the course of determining which type of practice and schools should be the recipient of grant money, the Rockefeller Foundation hired Abraham Flexner to thoroughly investigate all medical schools in the country for the first time. The report is eye-opening. Most of the naturopathic and homeopathic schools presented their students with very poor experiences – most did not require a college degree; none of the faculty was full time, and few of the students had access to actual patients in a mentoring atmosphere. Some of the schools were described as filthy, with libraries of only a few old books. By contrast, the schools that offered the best education required college degrees and 4 years of didactic and bedside education. If your mother developed a serious medical condition in the 1920’s, which type of graduate would you have wanted to see her?

These are not complementary veterinary professions. And I can already hear the defense - 'those veterinarians are just worried about competition'. No we're not. We're worried about what happens to sick pets whose owners don't know the difference between in-depth veterinary and natural medicine knowledge and a fake. If they know the difference and choose a "VND", the pet still suffers, but the owner is making an informed choice. The trouble is - most owners don't. So if that internet expert with a Dr. in front of her name offers consultations and sells supplements, it's a good idea to look for those letters, then make your decision.

Can anyone tell me why the new generation of "vet skeptics" are so insistent on remaining anonymous? I've been reading "skeptvet" and "skeptivet" but cannot determine from their "about" why they are qualified to question the experience and recommendations of specialists with more scientific training. Can someone help me here?

semantics

It's "veterinary medicine" or "veterinary practice". That's a noun with a descriptive adjective, telling you what we do.

"Veterinarian medicine" and "veterinarian practice" are incorrect. On so many levels. Don't do that.

Kthx.

Signed,
Grammar nazi

Grains #2 - not as allergenic as you thought

Grainless foods are popular these days. And sometimes rightfully so – I know many have seen a difference when they switch an ailing dog or cat from a standard grain-based food to one that is lower in "carbohydrates" (presumably starch). It’s wrong to blame the grains, though, in many cases (I’ve talked about this here before).

Quick tutorial: Carbohydrates are essentially fibers, sugars and starches. Some (starches and sugars, mostly) are digestible, and are degraded from large molecules on ingestion to small molecules that are absorbed in the small intestine for energy. Grains like barley, wheat, corn, and oats contain digestible and indigestible carbohydrates in addition to fatty acids and proteins – they are more complex than a simple carbohydrate such as starch. Digestible carbohydrates are also contained in root vegetables like potatoes and yams, yuca (or tapioca), taro root, etc.

My biggest quibble with companies that tout a ‘grainless’ label on a dry food is that they are not carbohydrate-less, which is in reality what most pet owners think they are getting when they search for a Paleolithic, low carb (i.e. low starch) diet. I’m just saying, pet owner beware, because you cannot make a dry food without some carbohydrate, and these companies will simply substitute a starch from potato, sweet potato, tapioca or the like to do it. That’s not necessairly a 'low carb’ food.

But I want to talk about today is why some animals do better when switched from a high starch, or even moderate starch food, to a low starch food.

Many people go looking for alternative pet foods because they are forced to – they have a chronically ill animal (“chronically ill” pretty much defining a condition not amenable to conventional therapy). You would almost have to live under a rock to avoid the advice you’d get from fellow pet owners, pet store employees and websites that grain-free diets fix everything from skin disease to GI disorders to cancer.

In the case of animals with chronic conditions of many types, the central problem may be a sick gut. We used to (and still do) call this a leaky gut, but more recently gastroenterologists have come to agree that the condition exists, and call it a hyperpermeable gut. Chronic inflammation of the gut may appear due to food allergy or less well understood inflammatory processes like inflammatory bowel disease. Even a transient gastroenteritis or antibiotic therapy can lead to inflammation of the gut lining.

There are probably many arthritic dogs on long term therapy with nonsteroidal anti-inflammatory agents such as Metacam®, Previcox®, Deramax®, and Rimadyl® walking around with leaky guts, as well. The syndrome even has a name – NSAID enteropathy. For your edification, a review from the Journal of Pharmacy and Pharmaceutical Science in 1999 stated unequivocally that in people, “NSAIDs produce inflammation of the small intestine in 40 to 70% in long-term users” (Davies 2000). And if you’re really interested, “Exposure of the small bowel mucosa to NSAIDs is thought to lead to the loss of intracellular integrity and increased permeability because the NSAIDs damage surface membrane phospholipids and cause an uncoupling of oxidative phosphorylation” (Feagins 2010). Interestingly, NSAID use is also associated with lower numbers of Lactobacillus in the bowel (the good bacteria) which are known to improve gut mucosal integrity. (Mäkivuokko, 2009)

So chronic inflammation in the gut begins to erode the most superficial layers of the mucosal lining. The microstructure of the gut consists of tiny folds called villi, and the villi themselves have surfaces composed of enterocytes (cells of the gut mucosa) that have microvilli on the end that is exposed to the gut lumen. These cells actively secrete enzymes and other products that aid in normal digestion, absorption, and even immunity, and these products become more active as they mature, moving from the deeper layers of the gut to the tips of the microvilli. So what happens when the most superficial layer of the gut is eroded away due to inflammation?

One of the earliest theories from holistic medicine writers was that the gut immune system is exposed to abnormally intact molecules of food, and the animal (or person) subsequently develops food allergy or gluten enteropathy. Since the immune system can potentially become sensitized to any protein ingested, the poor patient experiences signs of food allergy constantly, including skin inflammation and diarrhea, and if you read the more esoteric literature, arthritis and a wide variety of autoimmune diseases.

But another circumstance suggests a simpler explanation for the inconsistent stool we see in some of these animals that eventually improve on a ‘grain free’ or low carb diet. In the ‘stressed’ enterocyte, mature digestive enzymes – disaccharidases that digest starches and sugars – are lost because of erosion of the luminal end – the part that is exposed to the GI contents, NSAIDs, etc. Examples of disaccharidases include lactase, maltase, sucrase, trehalase, isomaltase, and others.

So, disaccharides that result from digestion of more complex carbohydrates in the stomach and upper intestine flow down into the small intestine where disaccharidase enzymes would further digest them into a form that is easily absorbed. If they remain in disaccharide form, they are not absorbed and in fact pull water into the intestine. The result is loose stool, or diarrhea.

The problem is compounded the longer it exists. Carbohydrate malabsorption will lead to increased bacterial fermentation, which will cause gas and discomfort. Bacterial overgrowth (due to a surfeit of nutrition for them) can itself lead diarrhea.

So the neighbor comes along and recommends a grain-free diet, and the dog or cat gets better, and once again, the grains get the blame, when in actuality, the *starch* should get the blame. While allergy may or may not be a component of the reaction seen when grains are fed to these animals, the carbohydrate overload seems to be a bigger problem. And as I said before, carbohydrates are certainly common in ‘grain free’ diets - grain free does not mean low starch.

The good news is this – and I can verify that clinically this is extremely common – these ‘allergies’ aren’t permanent, unless the patient has a genetic disaccharidase deficiency (which is vanishingly uncommon in dogs and cats). In general, balancing the bacterial populations with probiotics, changing the diet so that it contains lower carbohydrate levels and sometimes different proteins, and addressing the cause of the initial bowel inflammation is all that is needed. Whether or not the owner wants to go back to feeding a diet higher in carbohydrates depends on other factors, like owner philosophy, financial capacity to buy the more expensive meat products, and whether the dog or cat has a weight problem (carbohydrates are used in weight loss diets to ‘cut’ the fat while still giving some bulk to the diet).

I just had to get this out there. Temporary carbohydrate intolerance is different from real food allergies. It's a much better diagnosis for your pet though, as there are no permanent food restrictions.

References
Davies NM, Saleh JY. Detection and Prevention of NSAID-Induced Enteropathy.J Pharm Pharmaceut Sci 3(1):137-155, 2000

Feagins LA, Cryer BL. Do Non-steroidal Anti-inflammatory Drugs Cause Exacerbations of Inflammatory Bowel Disease? Digestive Diseases and Sciences 2010;55(2):226

Mäkivuokko H, Tiihonen K, Tynkkynen S, Paulin L, Rautonen N. The effect of age and non-steroidal anti-inflammatory drugs on human intestinal microbiota composition. Br J Nutr. 2010 Jan;103(2):227-34. Epub 2009 Aug 25.