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Health & Human Services Inspector General Finds Dietary Supplement Companies Make Misleading, Unsupported Claims and Ignore FDA Regulations

Posted on December 9, 2012 by skeptvet

I have discussed the bizarre and ineffectual regulatory scheme for dietary supplements in detail previously. The stunningly misnamed Dietary Supplement Health and Education Act (DSHEA) basically exempts any product called a “supplement” from any meaningful regulation to ensure safety or truthfulness in advertising. Companies selling supplements aren’t supposed to make claims about their products without good scientific evidence, and they aren’t allowed to claim to treat any specific disease, only to support the body’s normal “structure and function.” And all such products are supposed to carry the Quack Miranda Warning, which basically says the FDA hasn’t evaluated the companies’ claims and can’t guarantee the product is safe or effective.

Unfortunately, compliance is totally voluntary with no oversight or enforcement mechanism. The FDA isn’t allowed to verify the truthfulness of any marketing claims before a product goes on the market, and the burden for showing a product is harmful after it available is so high it is almost impossible to stop the sale of anything marketed as a dietary supplement. The fox is the only one with a key to the henhouse.

The government has repeatedly found casual and widespread violation of even the very limited regulations that exist. The FDA has found serious safety and quality control lapses in dietary supplement manufacturing. The GAO has reported on deceptive marketing of herbal remedies. And now the Department of Health and Human Services Inspector General has issued a report confirming that the “structure and function” claims analyzed for 127 supplements failed to meet even the limited requirements of DSHEA. The report concluded:

Overall, substantiation documents for the sampled supplements were inconsistent with FDA guidance on competent and reliable scientific evidence. FDA could not readily determine whether manufacturers had submitted the required notification for their claims. Seven percent of the supplements lacked the required disclaimer, and 20 percent included prohibited disease claims on their labels. These results raise questions about the extent to which structure/function claims are truthful and not misleading.

The report illustrates both the toothlessness of the voluntary guidelines as well as the lack of real scientific evidence to support the kinds of claims supplement manufacturers routinely make. Only 66 out of 104 companies contacted even agreed to submit information to investigators supposedly substantiating the claims they made for their products. And the documents that were submitted did not justify any confidence in the claims these manufacturers make. A few telling details from the report:

In contrast to FDA guidance, most substantiation was not derived from human studies.

Of the 34 percent of substantiation documents that were human studies, none met all of FDA’s recommendations for competent and reliable evidence.

10 percent of the documents appeared to have no significance in supporting structure/function claims.

FDA guidance recommends that when determining whether a claim is substantiated, manufacturers should consider all available scientific evidence—both favorable and unfavorable—and present the evidence in context. Interviews with staff at the National Center for Complementary and Alternative Medicine at the National Institutes of Health indicated that a large body of science exists that contradicts existing structure/function claims. Yet, 96 percent of the human studies we received were favorable to the supplements’ claims, suggesting that manufacturers either have not considered the body of available scientific evidence, that there is a positive bias in the documents selected to substantiate their claims, or that no such contradictory evidence exists.

85 percent of the 557 human studies we reviewed were not randomized, double-blind, parallel group, placebo-controlled trials.

49 percent of the human studies were not based on populations similar to those that will be consuming the supplements.

Seven percent of supplements in our sample were missing the required disclaimer for structure/function claims

Overall, the evidence submitted to support claims made about the effect of these supplements were cherry-picked to appear more positive than the total body of evidence available, consisted largely of unreliable pre-clinical studies and a few poor-quality clinical trials, and often had nothing at all to do with the claims being made. And presuming that those companies willing to voluntarily submit their supporting evidence had, in fact, better evidence to offer than those companies who ignored the request, it is very likely that most structure and function claims are completely without any basis in science at all.

It never ceases to amaze me that people rail vociferously (and often with good reason) at the misdeeds of pharmaceutical companies and yet seem perfectly comfortable with allowing a multi-billion dollar herb and supplement industry monitor itself and make barely even token efforts to find out if their products are safe or do what they are being taken for. This report recommends that the FDA seek the statutory authority to verify structure/function claims, and that would be a good start, though it seems unlikely in the current political climate. What would make even more sense, and would be more likely to protect the public from unsafe and ineffective supplements and deceptive advertising, would be to scrap DSHEA and regulate all medical products by the same, science-based standards of evidence. Sadly, something that reasonable seems even less likely to be possible.

AVMA Considers Resolution Acknowledging Homeopathy is Ineffective

Posted on December 2, 2012 by skeptvet

A recent article in the Veterinary Practice News (VPN) revealed that the American Veterinary Medical Association (AVMA) is considering a resolution, proposed by the Connecticut Veterinary Medical Association (CVMA), relating to homeopathy, specifically, and to the role of science and scientific evidence in evaluating veterinary therapies more generally. The full text of Resolution 3 is available here, but the core of the measure consists is the following:

RESOLVED, that the American Veterinary Medical Association (AVMA) affirms that—

1. Safety and efficacy of veterinary therapies should be determined by scientific investigation.

2. When sound and widely accepted scientific evidence demonstrates a given practice as ineffective or that it poses risks greater than its possible benefits, such ineffective or unsafe philosophies and therapies should be discarded.

3. In keeping with AVMA policy on Complementary and Alternative Veterinary Medicine, AVMA discourages the use of therapies identified as unsafe or ineffective, and encourages the use of the therapies based upon sound, accepted principles of science and veterinary medicine.

4. Homeopathy has been conclusively demonstrated to be ineffective.

The resolution is supported by a detailed white paper, The Case Against Homeopathy.

The first three statements in the resolution are not likely to be controversial, and they are already included, usually implicitly, in a number of existing policy statements. The most directly relevant is the AVMA Policy on Complementary and Alternative Medicine, which states, “Claims for safety and effectiveness ultimately should be proven by the scientific method… Practices and philosophies that are ineffective or unsafe should be discarded.”

This has been the official policy of the AVMA for over a decade. However, no alternative therapy has ever been acknowledged to be ineffective or discarded, including homeopathy. There is, as the white paper makes clear, overwhelming evidence that homeopathy has no benefit beyond placebo, but because it is a belief system rather than a medical discipline, practitioners of homeopathy are unlikely to ever accept this. The final statement in the resolution is controversial only because this small group, passionate and ideologically committed to homeopathy, will undoubtedly challenge it vigorously.

And despite the fact that the vast majority of veterinarians do not practice homeopathy, any criticism of practices other veterinarians employ, regardless of the evidence against them, seems to have become virtually taboo within the profession. Collegiality and unity sometimes seem to take precedence over science and the interests of our patients and clients. However, there are a number of reasons why this resolution is important for the profession, as well as patients and their owners.

As has been discussed frequently before (1-8), offering homeopathic treatment without clearly identifying it as a placebo is unethical. It places patients at risk by substituting an ineffective therapy for real treatment, and it denies pet owners the right to make fully informed decisions about the care of their pets. Mainstream veterinary medicine has left behind bloodletting, purgatives, and many other 18^th and 19^th century therapies which failed the test of scientific validation, and it is not in the interests of our patients, our clients, or our profession to endorse a belief system like homeopathy which has similarly failed to generate meaningful evidence of real benefits beyond placebo effects in the last two hundred years.

Several organizations have endorsed the proposal. The Evidence-Based Veterinary Medicine Association has issued this statement urging passage of the resolution:

The AVMA has issued many policy statements acknowledging that veterinary medicine should be based on sound, legitimate science. The AVMA Policy on Complementary and Alternative Medicine, for example, states, “Claims for safety and effectiveness ultimately should be proven by the scientific method… Practices and philosophies that are ineffective or unsafe should be discarded.” However, despite overwhelming evidence and consensus among scientists that homeopathy is ineffective, a few veterinarians continue to promote it as an adjunct or alternative to conventional scientific medicine. This diminishes the credibility of the veterinary profession and does a disservice to our patients and our clients.

Other national veterinary groups, including the Australian Veterinary Association and the British Veterinary Association, have publically acknowledged that homeopathy is not an effective therapeutic approach. As the leading veterinary association in the world, it is important that the AVMA also demonstrate its commitment to modern, evidence-based medicine and the interests of our patients and the public. Resolution 3 protects the integrity of the AVMA and the veterinary profession as well as the trust of the public on which we depend.

The EBVMA Board of Directors unanimously endorses Resolution 3 and the supporting documents introduced to the AVMA House of Delegates by the Connecticut Veterinary Medical Association, and we encourage you to support passage of this important policy statement.

There have also been endorsements from the American College of Veterinary Clinical Pharmacology (ACVCP) and the American Academy of Veterinary Pharmacology and Therapeutics (AAVPT). Not surprisingly, the Academy of Veterinary Homeopathy (AVH) and the American Holistic Veterinary Medical Association (AHVMA) are fighting the measure. According to the VPN article,

Proponents of homeopathy welcome introduction of the resolution.

“This is a wonderful chance for us to educate other vets about the benefits of homeopathic veterinary medicine,” said Jeff Feinman, VMD, CVH. “The main argument [against] homeopathy is that it’s implausible, and we will show that that’s not true at all. The research is just now catching up with the basic science.”

It will be interesting to see how homeopaths attempt to make the argument that homeopathy is actually consistent with basic scientific knowledge, given the strong case to the contrary (for example, The Science of Homeopathy).

I suspect the attempt will involve some reference to quantum physics. By virtue of being strange, counterintuitive, and impossible to truly understand without fluency in advanced mathematics, quantum physics is a popular rope among proponents of pseudoscientific therapies like homeopathy. The argument seems to be something along the lines of, “Quantum physics is weird and true. Homeopathy is weird. Homeopathy must be true.”

There are a number of problems with this fallacious argument, including the fact that there is no demonstrated connection between the oddities seen at the subatomic level and the notion that water which once had some kind of substance in it magically remembers that substance and can thus cure patients afflicted with symptoms that might or might not be caused, in healthy patients, by that substance.

Another argument the AHVMA brings up in their comment about the resolution is that no homeopaths were consulted by the CVMA in developing the proposed resolution. The AHVMA says, “when anyone considers a modality, they should talk to people who are considered experts in the field.” This sounds quite reasonable, but it skips over the fact that homeopathy is not a recognized medical specialty in which one can legitimately be said to be an expert. Though homeopaths have gotten together and created certification standards for themselves, these are not recognized by the American Board of Veterinary Specialties, The European Board of Veterinary Specialties, the American Board of Medical Specialties, or any other organization responsible for identifying and accrediting medical experts. Astrologers and Psychics have organizations that accredit practitioners of these methods, but that’s not a mark of legitimacy to those practices.

Ordinary veterinarians are capable of evaluating the scientific evidence and drawing a reasonable conclusion on the merits of homeopathy. Homeopaths, on the other hand, will never acknowledge the lack of evidence supporting their claims since to do so would be to invalidate their own profession. So the suggestion that the AVMA should set up a “task force” to evaluate homeopathy and advise the House of Delegates is like arguing that creationists should advise school boards on how to teach evolution. We don’t need task forces with specialists in bloodletting, faith healing, or other belief systems claiming, against significant evidence, to be medical therapies, and there is no reason to have one for homeopathy.

The AVMA House of Delegates will debate Resolution 3 on January 5. The delegates consist of representatives of the state veterinary medical associations and a number of allied organizations. The list of delegates can be found here. I encourage all veterinarians to contact their delegates and urge them to support this resolution.

References

Smith, K. Against homeopathy-A utilitarian perspective. Bioethics. 2012;26(8):398-409. which is reviewed at this link, for those who do not have access to the journal: http://www.sciencebasedmedicine.org/index.php/placebos-as-medicine-the-ethics-of-homeopathy/
Freckelton I.Death by homeopathy: issues for civil, criminal and coronial law and for health service policy. J Law Med. 2012 Mar;19(3):454-78.
Smith, K. Why homeopathy is unethical. Focus on Alternative and Complementary Therapies 2011;16(3):208–211.
Shaw D. Homeopathy is where the harm is: Five unethical effects of funding unscientific “remedies.” J Med Ethics. 2010;36:130-131
Shaw D. Unethical aspects of homeopathic dentistry. Br Dent J. 2010 Nov 27;209(10):493-6.
Ernst, E. The ethics of complementary medicine. J Med Ethics 1996; 22: 197-198.
Rollin, B. and Ramey, D. “Ethics, Evidence, and Medicine” in Ramey, D., Rollin, B. Complementary and Alternative Veterinary Medicine Considered. Iowa State Press, 2004.
Rollin, B. An ethicist’s commentary of the case of a veterinarian utilizing homeopathic therapy. Can Vet J. 1995 May; 36(5): 268–270.

Eric Weisman Gets Fine and Probation for Violating Court Order

Posted on November 21, 2012 by skeptvet

I recently received a comment from Mr. Eric Weisman, promoter of Evolution Diet, regarding a post I wrote about his products in 2009. The comment was full of conspiracy theories, baseless accusations, and a general disregard for truth. At that time of my original article, I knew only that Mr. Weisman was making claims about his diet, as well as other commercial diets and veterinary medicine as a profession, that were untrue and without any basis in fact. It later became clear that Mr. Weisman isn’t interested in facts at all when a reader pointed out that Mr. Weisman had been sanctioned numerous times for violating the terms of his license as a chiropractor and for practicing veterinary medicine without a license. In an update to my original post, I made available the public documents showing this pattern of dishonest behavior, for which Mr. Weisman ultimately lost his license to practice chiropractic.

Unfortunately, this did not disabuse him of the mistaken belief that he was qualified to practice medicine on both humans and animals, since he was subsequently charged with violating the terms of this court injunction along with new counts of practicing medicine without a license and mistreatment of animals, as I reported in an update last year. The allegations included some horrific descriptions of unethical behavior, including this from a veterinarian at the University of Minnesota,

Weisman brought in a cat he suspected had kidney failure and cancerous lesions, the complaint said. According to the U’s veterinarian, the cat had neither – it died of pneumonia, was unable to absorb nutrients from the food it ate and had broken bones in each of its front legs. The suspected cancerous lesions, the veterinarian said, were actually scabs caused by the cat walking on its joints instead of its broken feet, the complaint said.

Earlier this year, Mr. Weisman and the authorities reached a plea deal in which he pled guilty to violating the terms of his earlier court agreement. In return for this plea, he received a fine a 90-day suspended sentence, and probation, and the other charges were dropped. Interestingly, Mr. Weisman did not deny that he diagnosed a dog with cancer and prescribed treatment for it or that he recommended treatment to a man with lymphoma, he merely claimed that in doing so he explicitly told them he wasn’t a doctor and so was not legally allowed to practice medicine. Apparently, this disclaimer, followed by behavior indistinguishable from the practice of medicine, is sufficient to absolve Mr. Weisman of legal responsibility for his actions.

Naturally, Mr. Weisman sees his conviction as a vindication, and it’s hard not to see why when such egregious disregard for the law of the truth meet with such mild sanction. And it seems clear that no lesson has been learned here. While sprinkling his web site with disclaimers about not being allowed to practice veterinary or human medicine, statements like this are still to be found there:

Q. I have concerns about how healthy a Vegetarian Diet is for my Pet. My pet is having some problems and I have been feeding my pet another pet food or Evolution for a while and I’m not sure if it’s the food causing the problem.

Please phone me immediately with any Health Concerns at 651-221-9056 and leave a message for me, Eric Weisman, Scientist, Dr. of Health Sciences. I have helped many Dogs, Cats, Ferrets and Humans with Health and Behavior Issues in 1000’s of cases. I am an internal disease expert with many years of both Nutrient Compound Procedure and Drug-Surgery Health Experience and feeding a Meat Based or Vegetarian Diet to many types of animals, including wild outdoor animals and exotic pets. Although it is far better to phone for the fastest response, you may also e-mail us about health, behavior, and product issues at weisman@qwestoffice.net. For Urgent issues,call 651-492-2190.

We can tell you exactly how we treat a Dog, Cat or Ferret with the same or similar condition you or a veterinarian describes. I will give you the most accurate information possible about our Nutrient Compound Procedures. I can also use your Veterinary Diagnosis and we can review your Veterinary Lab Work & Diagnosis. I would also be glad to work with your veterinarian, although that will involve extra veterinary expense. Again, I will tell you about all the supplements and what we do in the same or similar case. Because of current law, we can not refer to our Nutrient Compound Procedures as a diagnosis, prevention, treatment or cure. I am a former physician with 23 years of experience with humans. I have worked and helped people in thousands of cases with their dogs, cats and ferrets for 20 years explaining exactly how I use nutrient, botanical and pharmaceutical procedures in cancers, immune system disfunction and failure, infectious disorders, kidney and liver failure, etc..

Despite have no recognized medical credentials, Mr. Weisman is willing to make recommendations and sell products to people with ill pets by representing himself as “an internal disease expert” and a “former physician” (not a former chiropractor stripped of his license, which would be accurate). This seems quite clearly to violate the terms of Mr. Weisman’s plea, but ultimately that is up to the Minnesota Attorney General, or perhaps the Little Canada City Attorney.

Posted in Law, Regulation, and Politics, Nutrition | 4 Comments

Can you own an idea? Hemopet sues Nestle-Purina and Hill’s over Nutrigenomics.

Posted on November 13, 2012 by skeptvet

Intellectual property law is a complex, often bewildering tangle that I make no claim to be deeply conversant with. However, it has always struck me as odd to consider the notion that ideas can be owned. While I understand the purpose of allowing innovators to profit from their work, I also see knowledge, particularly knowledge about the physical world to which we all have access, as something impossible, or at least inappropriate, to try and restrict in the pursuit of market advantage. In any case, whatever one thinks about the underlying philosophical and moral issues, the processes of claiming and enforcing ownership of an idea often make interesting narratives.

A recent example is a lawsuit filed by veterinary Hemopet, a blood blank and diagnostic testing company founded by Dr. Jean Dodds, and the pet diet manufacturer Nestle-Purina. Dr. Dodds is herself a complex character. She has done great and important work in promoting transfusion medicine and is well-regarded as an advocate and researcher, though without a traditional academic background or affiliation. She is undoubtedly a pioneer in veterinary medicine.

However, like many pioneers she holds a number of views which are not compatible with a conventional medical or scientific understanding, and her accomplishments do not automatically make these views legitimate. She goes beyond the available evidence in claiming that vaccines are an established and important cause of disease (so-called vaccinosis). Her theories about thyroid disease are not generally accepted by endocrinologists, though they are widely promoted by practitioners of alternative veterinary medicine. In fact, Dr. Dodds’ ideas are quite popular with this community, and in addition to being on the board of the American Holistic Veterinary Medical Foundation, she has been awarded the honor of Holistic Veterinarian of the Year.

This current lawsuit stems from a couple of other projects of Dr. Dodds which are not part of mainstream science-based medicine. She has developed a method which she claims can identify dietary sensitivities in animals through testing saliva (a claim most immunologists and dermatologists do not accept), and she has patented an idea for implementing a nutrigenomics program for identifying and modifying disease risk in animals.

Nutrigenomics is an interesting idea. The theory is that the expression and function of genes interacts with specific nutrients in a way that can be identified and manipulated through gene sequencing, dietary modification, and other diagnostic, preventative, and therapeutic practices. If that sounds vague, it is. The idea is far from being established even in general principle, much less in actual clinical practice, and there is little evidence to suggest any specific diagnostic or therapeutic approach that can be owned and marketed exists. The term nutrigenomics, and the small amount of laboratory research suggesting that it might one day be a real approach to health, have been used to market specific products well before this is justified by appropriate scientific evidence. And not only has Dr. Dodds joined in this practice, she is apparently willing to sue to assert her ownership of the general idea in animals.

The initial details of the lawsuit, and the patents Hemopet alleges have been infringed, are contained in this complaint:

Hemopet v.Nestle-Purina Petcare Company Patent Infringement Complaint

There is a great deal of repetitive verbiage describing the patents held, but the general sense is that Hemopet has patented the idea of using a comprehensive computer database containing information about individual animals and groups of animals, as well as the results of both legitimate and questionable or misapplied laboratory tests, to identify health risks and appropriate nutrition for companion animals. The description seems to envision a database and consulting system made available, for a fee, via the Internet. Here are a few selections from the patents:

…it is necessary in animal health diagnosis and care that appropriate predictive testing for diseases and disorders of animals be achieved in order to reduce morbidity and mortality, and improve the quality of life and lifespan. Currently this is not done in relation to the health assessment data of an animal together with the genetic data related to that same animal. Current tests do not provide as much data as possible to attain correct diagnosis and disorder predictions with the net result of an improvement in the quality of life and increased longevity.

The disclosure is directed to a method, apparatus and system of obtaining, analyzing and reporting laboratory test data in relation to the health assessment data of an animal together with the genetic data related to that same animal.

The disclosure also provides a bioinformatics system for inputting, controlling, analyzing and outputting of a broad range of criteria related to the health, genetic background and longevity of animals. This includes a system concerning phenotype data and genetic data relating to animals. Further, there is provided a system for screening of genetic data and genomic mapping, and integrating the phenotype health assessment data and genetic identifier and assessment data in a computerized data processing resource (“CDPR”).

The present disclosure offers a unique solution to above-described problems by providing an apparatus, method and system, in relation to animals, for performing data analyses of biological specimens from specific subject animals or animal groups in relation to specific subject animal or animal groups of genetic data. The apparatus, method and system comprises a controller for obtaining, inputting, and analyzing biological, physiological, and pathological test data together with genomic mapping and genetic screening data into the CDPR.

The biological, physiological, and pathological data of the subject animal or animal group and the genetic data of the subject animal or animal group are communicated to a remote user as raw data or as related, analyzed biological, physiological, and pathological data and genetic data. The remote user can also appropriately access the CDPR to input data to, or obtain data from, the CDPR.

The disclosure also includes the step of reporting the determination of the health care, well-being, nutrition or other therapeutic requirements and suggestions or health on a communications network including the Internet. Preferably, there is a payment procedure for the report which is achieved through the Internet.

A further aspect of the disclosure is the accessibility of the health assessment database and/or genetic database or other databases of the CDPR by the remote user selected on the basis of password, security control, and financial payment such that the data can be transmitted into and from the CDPR by a computer network. Use of selected passwords, encryption systems, and payment systems are employed to facilitate and restrict the flow of data in and/or out of the databases.

A diagnosis of the health of an animal is obtained through a combination of computerized data analysis, and human interpretation. Data relates to the physical characteristics of the animal, and includes data obtained from a physical inspection of the animal. A blood or other fluid sample is used to obtain a computer generated laboratory analysis. This is reported through an internet network to specialist for analysis by a specialist clinical pathologist. The clinical pathologist has the data relating to the physical characteristics, and thereby makes a diagnosis of the animal’s overall health status.

So what appears to have been patented here is the idea of collecting a wide range of pieces of information about an animal in a computer, passing it around to people, and using it to “reduce morbidity and mortality, and improve the quality of life and lifespan” in companion animals. It’s hard to see how this could be a patentable idea, or even truly original apart from the unsubstantiated general claims about the links between gene sequences and health, but again I’m not expert in patent law. And despite a list of scientific papers included with the patent application (but not used as specific citations to support particular claims), it’s not clear that there is an actual preventative or therapeutic healthcare intervention here.

So how has Nestle-Purina allegedly violated the ownership of this very general idea? That’s not entirely clear from the complaint either. The allegation is that,

Purina has infringed and continues to infringe the ’343 patent by its manufacture, use, sale, importation, and/or offer for sale of its products and services developed using molecular nutrition or ‘-omics platforms,’ including Purina’s Veterinary Diet JM and OM products.

Again, it appears that the basis of the complaint is that Hemopet owns the idea of nutrigenomics and that Nestle-Purina has stolen this idea by utilizing this method which, from a scientific point of view, doesn’t really exist yet. Nestle-Purina does claim on its website to use nutrigenomics in developing its diets:

Nestlé Purina scientists use molecular and functional genetics to help them understand the “why” behind dog health. Our goal is to impact the processes through nutrition.

Nestlé Purina scientists use molecular nutrition to identify gene-expression changes related to specific health conditions and examine how nutrition can help manage canine health. Whether scientists are studying the nutritional management of obesity, joint conditions, or food allergies, molecular nutrition helps them to fully understand the biological context of certain changes and how they can be used in order to benefit dogs.

How exactly the company does this given the embryonic, even blastocystic, state of current knowledge about genes and nutrients, isn’t explained.

So we have a theoretical approach to health and nutrition which has not yet been validated scientifically. Hemopet claims to own it. And Nestle-Purina claims to use it in developing its pet foods. You might think Dr. Dodds would approve of this, given her apparent lack of confidence in the healthfulness and safety of current commercial foods and her belief that nutrigenomics is the right way to approach nutrition, but apparently not. In any case, it’s a bit baffling how these two organization can compete for ownership of an idea which doesn’t really exist in a tangible form yet.

I’ve written before about the fact that the legal system has very different priorities than the systems of science. Malpractice lawsuits involving alternative medicine, for example, rarely hinge on whether the practice being challenged is scientifically legitimate or can be shown to be safe or effective. The lawyers and judges involved seem more interested in the balance of state power and individual liberty than whether the therapy at issue is legitimate or pseudoscientific nonsense. And individuals often and easily get away with egregiously ridiculous medical practices entirely incompatible with science despite laws that sound like they should protect the public from such people. And securing a patent has more to do with proving an idea is original that proving it is true or actually works, as evinced by the weird and clearly implausible things that can be patented.

So I suppose it shouldn’t be a surprise that Hemopet can claim to essentially own the concept of nutrigenomics and choose to sue Nestle-Purina for claiming to use it. It does seem, however, like putting the cart before the horse, since who gets to profit from a new approach to health and nutrition should at least have something to do with whether the approach actually works and who has done the work to demonstrate this. But maybe that’s why I’m a scientist and not a lawyer.

Addendum-

A reader was kind enough to point out that Hemopet is also suing Hill’s Pet Food for apparently the same violation of its ownership of the idea of nutrigenomics. Here’s the complaint:

Hemopet vs.Hills Pet Nutrition

Hill’s does also claim to use nutrigenomics, though again it isn’t clear what exactly that means.

Posted in Law, Regulation, and Politics | 11 Comments

Another Study Shows CAM Use Harms Cancer Patients

Posted on November 11, 2012 by skeptvet

A recent study of cancer patients provides yet another addition to my list of examples of how complementary and alternative medicine (CAM) can do harm.

Yun YH, Lee MK, Park SM, Kim YA, Lee WJ, Lee KS, Choi JS, Jung KH, Do YR, Kim SY, Heo DS, Kim HT, Park SR. Effect of complementary and alternative medicine on the survival and health-related quality of life among terminally ill cancer patients: a prospective cohort study.Ann Oncol. 2012 Oct 30. [Epub ahead of print]

This study was a prospective cohort study which followed 481 terminally ill cancer patients in Korea. The authors compared the use of any alternative therapy with the use of no such therapies, so obviously the study does not evaluate the effectiveness of individual treatments. Its purpose was to see if overall the use of CAM had a measurable effect of survival or quality of life for cancer patients. The essential findings were these:

There was no overall difference in survival between patients who used CAM and patients who didn’t.
Overall, CAM users exhibited poorer cognitive function and more fatigue than non-users.
A series of subgroup analyses (always to be viewed skeptically) identified a number of poorer quality of life scores among CAM users and a poorer survival among those who used prayer as a healing intervention.

This is certainly not the definitive word on CAM in general, nor a clear disproof of the value of any particular CAM practice. What it is, is a sound rebuttal to the unsubstantiated claims that CAM use improves the survival or well-being of cancer patients. It also provides yet another stone in the avalanche of evidence that the blithe assumption that even if CAM doesn’t help it can’t hurt. Previous studies of both general CAM use and specific CAM practices, have found not only no benefit but a significant decrease in the survival and the quality of life of cancer patients using CAM.

All therapies need to be rigorously evaluated scientifically, beginning with the establishment of a plausible theoretical principle, progressing to proof of concept in animal model and in vitro studies and, if this information warrants it, ultimately being subjected to clinical trial evaluation to prove real safety and efficacy. The assumption of either efficacy or safety based on tradition, intuition, theoretical reasoning, or low-level preclinical evidence not only wastes resources on useless therapies but harms patients.

Additional Examples
Kurian Joseph, Sebastian Vrouwe, Anmmd Kamruzzaman, Ali Balbaid, David Fenton, Richard Berendt, Edward Yu and Patricia Tai. Outcome analysis of breast cancer patients who declined evidence-based treatment.World Journal of Surgical Oncology 2012, 10:118.

Lim A, Cranswick N, South M. Adverse events associated with the use of complementary and alternative medicine in children. Arch Dis Child. 2010 Dec 22. [Epub ahead of print]

Chang EY, Glissmeyer M, Tonnes S, Hudson T, Johnson N. Outcomes of breast cancer in patients who use alternative therapies as primary treatment.Am J Surg. 2006 Oct;192(4):471-3.

Bostrom, H. Rostrom, S. Quality of alternative medicine–complications and avoidable deaths.

Han E, Johnson N, Delamelena T, Glissmeyer M, Steinbock K. Alternative therapy used as primary treatment for breast cancer negatively impacts outcomes. Ann Surg Oncol 2011;Jan 12 [Epub ahead of print

The Danger of Choosing Alternative Therapies Over Conventional Care

Posted in General | 4 Comments

Caregiver Placebo Effects: New Study Shows that Owners and Vets Often Believe an Ineffective Therapy is Working When it Isn’t

Posted on November 4, 2012 by skeptvet

The placebo effect is a critically important, and much misunderstood phenomenon which can mislead us greatly when we are trying to decide if a medical therapy is or is not effective. While most people understand the placebo effect to mean a patient feels better because they think they are getting a real therapy, when actually they are getting a fake therapy, this is only one kind of error included under this label.

Belief and expectation can certainly cause people to imagine an improvement in their condition even when they aren’t getting a real treatment, and even when objectively their disease is unchanged or getting worse. One relatively recent example is a study of placebo treatments, including acupuncture, for asthma. In this study, fake therapies frequently made people feel their asthma symptoms were reduced, but objective measures of lung function didn’t change. This sort of result indicates pretty clearly that even if people report feeling better, it is not a good idea to rely on placebo effects alone because they don’t actually improve the condition being treated. There may be some value to improvements in subjective symptoms like pain even if they aren’t real, but we cannot ignore the fact that these improvements can occur even when the people feeling better are actually getting sicker.

There are many other sources of error in scientific studies of medical treatments that can lead to a false impression of improvement even if a therapy doesn’t work. Regression to the mean, the Hawthorne Effect, the natural course of disease, and many other similar phenomena can fool us into thinking a therapy is working when it isn’t, or lead us to believe the effect of a treatment is stronger than it really is. These are often called placebo effects because they can be controlled for in experimental studies by having a placebo treatment group, but they don’t involve belief or expectation on the part of the patient. Many of these effects occur in animals just as they occur in humans, even though animal patients likely do not have beliefs or expectations about their health. Even with a problem as apparently objective and straightforward as epileptic seizures, significant placebo effects have been seen in dogs.

One source of error seen in studies of medical therapies in humans, and which likely also operates in veterinary medicine, is the placebo effect by proxy (e.g. 1, 2). This is where the beliefs and expectations of someone caring for a patient (often a parent) influence the apparent effect of a medical treatment because the parent either reports on the effect of therapy or behaves differently in other ways related to the treatment being tested. Often, this effect makes it look like patients are improving by the subjective measure of caregiver evaluation even if objective measures show the patient actually is not getting better.

I have long argued that this form of placebo effect is a serious problem in veterinary medicine, where subjective measures of response based on owner or veterinarian opinion are often used to evaluate the effect of therapies for veterinary patients. Inconsistent and usually positive subjective evaluations of response to treatment show up in almost every veterinary clinical trial, and without adequate controls for placebo effects, these can lead to false impressions of a benefit. This is especially a concern with therapies shown in humans to operate mostly or entirely by placebo effects.

One area in which this problem appears to be significant is the treatment of arthritis in veterinary patients. Many therapies are used which have not yet been demonstrated to be effective through high-quality clinical trials (such as stem cell therapies) or which have been shown in humans to operate mostly as placebos (such as glucosamine, acupuncture, and others), are tested in dogs and cats using only subjective assessment by owners or vets to determine if they are effective. A new study specifically evaluating the impact of caregiver placebo effects on evaluation of arthritis treatments illustrates why studies that don’t use objective measures or control for placebo effects are very likely to be misleading.

Conzemius MG. Evans RB. Caregiver placebo effect for dogs with lameness from osteoarthritis. Journal of the American Veterinary Medical Association. 2012;241(10):1314-1319.

This study looked at the assessment of lameness in 58 dogs who were in the placebo arm of a clinical trial evaluating a non-steroidal anti-inflammatory medication for arthritis treatment. The authors compared owner and veterinarian assessments of patient lameness with the results of an objective measurement tool that evaluated the amount of weight the dogs actually put on their arthritic legs. There were several important results that illustrate the importance of proxy placebo effects:

Objective measures were consistent throughout the study, while subjective evaluations were inconsistent and tended to show progressive improvement as the study progressed, even in dogs who were not actually improving.
A placebo effect in the owner evaluations occurred 56.9% of the time.
A placebo effect in veterinarian evaluations occurred between 40% and 45% of the time, depending on which specific method of evaluation was being used.
These placebo effects were highly significant at every point at which the dogs were evaluated (P<0.001).
Changes in lameness of </= 5% measured objectively were not unusual, but changes >/= 10% were rare, suggesting that small changes may occur naturally and can interfere with accurate evaluation of a therapy. Higher effect sizes should be seen if we are to have confidence that a therapy is truly working.

These placebo effects, seen in dogs not actually receiving any therapy for their arthritis, were highly significant and easily large enough to make an ineffective therapy appear effective without an objective measure of response. This illustrates quite clearly how important it is that we not accept only subjective assessments of arthritis treatments as proof that they work. We have to remember that the caregiver placebo effect means that the owner or veterinarian judge the patient to be improved, but actually the patient is likely in as much or more pain as they were without the treatment. Trusting in our uncontrolled observations to judge the value of treatments for arthritis pain very likely guarantees uncontrolled suffering for our pets and our patients.

Posted in General, Science-Based Veterinary Medicine | 12 Comments

HopeScience Vet’s EFAC for Periodontal Disease and Arthritis

Posted on October 24, 2012 by skeptvet

My attention was recently drawn to another dietary supplement product with pretty dramatic claims, this time for treating both oral disease (gingivitis and periodontal disease) and joint disease (osteoarthritis). As usual, the company web site and promotional materials are unequivocal about the benefits you can expect.

Comprehensive oral health care is now a reality!

Safe, No Side Effects…Only Side Benefits

A truly major advancement…

Far more effective and much faster acting than current natural joint products

Of course, there is the usual disclaimer, which one presumes is present because the company has not met the FDA requirements for making health claims:

This information is presented for informational purposes only and is not intended as an endorsement of any product. The information is not intended to be a substitute for visits to your local veterinarian. Rather, these testimonials / research pages and/or case studies offer the reader information written by pet owners and/or veterinarians concerning animal health and products that have shown results.

It is hard to imagine anyone actually claiming this information is “not intended as an endorsement of any product” given that the context is entirely product advertising, but that’s a relatively minor example of the weird things that happen when one tries to advertise a health care product not approved by the FDA as a health care product.

Several of the warning signs of bogus claims are present, including:

Claims of a major scientific breakthrough, initiated by a hunch or guess and an uncontrolled personal experience

Support for these claims primarily through testimonial and anecdote

Reference to scientific proof with few details

Claims of great benefits with absolutely no side effects

A money back guarantee

And while science is often used as a marketing point, this company goes farther, making several references to evidence-based medicine and making a number of statements about the need for meaningful scientific evidence with which I agree completely:

[this product is] not just another one of the multitude of unproven joint products, as it is also evidence-based. This is an often used term and at the same time an often abused term. As an example, we often see “contains clinically proven ingredients” In reality this usually implies that the actual product was in fact never tested clinically.

Esterified oils are the only evidence-based product for gum or periodontal health.

There is scientific support for natural approaches, but at the same time there are a lot of half truths and at times totally misleading statements made in order to sell products. We will let the science speak for itself.

The company also aggressively challenges the usefulness of what they appear to see as their major competition for the arthritis supplement market, glucosamine products. And here again, they make a case I am in complete agreement with about the lack of clinically meaningful, proven benefits for glucosamine supplements*:

It is quite amazing that so many people, including physicians just assume that glucosamine is effective. This is understandable when we consider how much joint health advertising that takes place. The sad reality is that in well controlled clinical trials that the placebo pills produced just as good effects as glucosamine.

Advertisers have frequently referred to GAIT and the 72 patient’s that seem to benefit, but they fail to mention the other 95% of trial participants or the fact that this 72 patient group went on to experience more cartilage loss than placebo.

So let’s take a look at this “evidence-based” product, what it is and what the evidence says about it.

What Is It?

The exact active ingredient in the product is listed as a “proprietary blend” of an “esterified fatty acid complex” from “beef tallow”. Esterified fatty acids are similar to other fatty acids, such as fish oils, with some chemical modifications. The other ingredients are a variety of vehicles and some compounds with Vitamin E activity, which are commonly included with fatty acid supplements since these tend to reduce Vitamin E activity in people or animals taking them.

Does It Work?

Given the heavy promotion of this as an “evidence-based” product, is there strong evidence to support the strong claims made for it? Well, not really.

The company claims, “EFAC has been studied with seventeen (17) animal and clinical studies, with six (6) studies presented at scientific meetings and six (6) published in pre-eminent scientific journals.” Of these, they provide links to 5 papers and once conference presentation, however all but one of the links are currently broken. It’s not clear what other studies they are referring to.

In terms of the use of esterified fatty acids in general (not this product specifically) for osteoarthritis, there are a few clinical trials that suggest some improvement in human patients with osteoarthritis. (1-3) These are the sort of small, early trials which can suggest a potential effect is worth investigating further, but the results often are not supported in larger, better controlled, and independently funded research. In fact, the clinical trial evidence supporting glucosamine as an arthritis treatment is far greater, and yet the largest and highest quality trials have turned out to show, as this company points out on their site, that there is not a real benefit. It seems a bit self-serving to correctly identify the weakness in the evidence for glucosamine and yet to aggressively promote their own product as “evidence-based” on the strength of far weaker clinical trial evidence.

As for the use of this product to prevent or treat gingivitis and periodontal disease, I have only found one related published paper, a report of a study involving the topical application of esterified fatty acids to the gums of 18 rabbits in which periodontal disease was artificially induced.(4) This is the sort of animal model study that is useful for providing proof of concept, but it is not appropriate to justify widespread clinical use in dogs and cats based on one laboratory study in rabbits. The company also claims a trial has been done in cats, and provides a testimonial from a veterinary dentist supporting the product, but apparently that study has not yet been published

The company also promotes the fact that they have been granted a patent for their product. This does not, however, have anything to do with whether or not it is effective. Evidence of clinical safety and efficacy is not required for a patent application, and patents have been granted for a wide range of bizarre and useless inventions.

Is It Safe?

A few safety studies in laboratory animals have been done and did not identify any hazards. I am also not aware of any reported side effects in humans or other species taking these supplements, though there does not appear to be any formal surveillance or reporting mechanism in place.

Bottom Line

It is certainly possible that esterified fatty acids could have clinically meaningful benefits. There is no clearly established physiologic mechanism by which this would occur, but there are a few small clinical studies in humans suggesting a benefit for osteoarthritis and at least one animal model study suggesting some benefit for periodontal disease. There is no evidence of any risk at this time.

At this level of evidence, the proper assessment is that benefits are possible but unproven. Use of the product would certainly be appropriate in controlled research studies and situations in which established therapies are not available or tolerated. Substituting these products for established therapies is not appropriate. And, unfortunately, despite all the talk of being scientifically validated and “evidence-based,” the claims made for these products go well beyond anything justified by published scientific evidence. Such language indicates only a recognition of the marketing value of science and the term “evidence-based medicine,” not any qualitative difference between the level of evidence behind claims for these products and that supporting similar claims by other nutritional supplements marketed to treat or prevent disease.

*Articles I have written about glucosamine for arthritis

Veterinary Glucosamine and Chondroitin

Growing skepticism about glucosamine for arthritis in dogs and cats

Is recommending glucosamine for arthritis evidence based medicine or wishful thinking?

Nope, glucosamine and chondroitin still don’t work in humans

Cognitive dissonance in action: Glucosamine no matter what!

References

Kraemer WJ, Ratamess NA, Anderson JM, et al. Effect of a cetylated fatty acid topical cream on functional mobility and quality of life of patients with osteoarthritis. J Rheumatol. 2004;31:767–74.
Kraemer WJ, Ratamess NA, Maresh CM, et al. Effects of treatment with a cetylated fatty acid topical cream on static postural stability and plantar pressure distribution in patients with knee osteoarthritis. J Strength Cond Res . 2005;19:115–121.
Hesslink R Jr, Armstrong D, Nagendran MV, et al. Cetylated fatty acids improve knee function in patients with osteoarthritis. J Rheumatol . 2002;29:1708–12.
Hasturk H, Goguet-Surmenian E, Blackwood A, Andry C, Kantarci A. 1-Tetradecanol complex: therapeutic actions in experimental periodontitis.J Periodontol. 2009 Jul;80(7):1103-13.

Posted in Herbs and Supplements | 24 Comments

Cranberry Products for Prevention of Urinary Tract Infections: An Update of the Evidence

Posted on October 22, 2012 by skeptvet

I have written previously about the rationale and evidence concerning the use of cranberry products to prevent or treat urinary tract infections. In my summary, I concluded:

There is weak theoretical justification for using cranberry products for urinary tract infections (UTI), though none of the supporting preclinical evidence involves dogs or cats. There is conflicting clinical trial evidence in humans, and no clinical studies in dogs and cats.

A recent Cochrane review concerning the use of cranberry products to prevent UTIs in humans further undermines the already weak argument for the value of these products. This update of the previous review in 2008 includes an additional 14 clinical trials in a meta-analysis. The conclusion was that there is no evidence cranberry products are effective for preventing UTIs:

Data included in the meta-analyses showed that, compared with placebo, water or not [sic] treatment, cranberry products did not significantly reduce the occurrence of symptomatic UTI overall (RR 0.86, 95% CI 0.71 to 1.04) or for any the subgroups: women with recurrent UTIs (RR 0.74, 95% CI 0.42 to 1.31); older people (RR 0.75, 95% CI 0.39 to 1.44); pregnant women (RR 1.04, 95% CI 0.97 to 1.17); children with recurrent UTI (RR 0.48, 95% CI 0.19 to 1.22); cancer patients (RR 1.15 95% CI 0.75 to 1.77); or people with neuropathic bladder or spinal injury (RR 0.95, 95% CI: 0.75 to 1.20).

Prior to the current update it appeared there was some evidence that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period, particularly for women with recurrent UTIs. The addition of 14 further studies suggests that cranberry juice is less effective than previously indicated….Given the large number of dropouts/withdrawals from studies (mainly attributed to the acceptability of consuming cranberry products particularly juice, over long periods), and the evidence that the benefit for preventing UTI is small, cranberry juice cannot currently be recommended for the prevention of UTIs. Other preparations (such as powders) need to be quantified using standardised [sic] methods to ensure the potency, and contain enough of the ‘active’ ingredient, before being evaluated in clinical studies or recommended for use.

Cranberry juice does not appear to have a significant benefit in preventing UTIs and may be unacceptable to consume in the long term. Cranberry products (such as tablets or capsules) were also ineffective (although had the same effect as taking antibiotics), possibly due to lack of potency of the ‘active ingredient’.

This review indicates pretty clearly that overall, cranberry juice is not effective in preventing UTIs despite theoretical reasons why it might be. This illustrates, yet again, why we cannot rely on extrapolation from pre-clinical or in vitro studies to tell us what will work in actual patients.

As always, one cannot completely rule out a subset of patients for whom these products might have benefits, but quite a variety of patient populations and different forms of cranberry have been investigated so far without any convincing evidence of value. And, of course, there is no clinical research at all in veterinary species to support using cranberry products to treat or prevent UTIs.

Posted in Herbs and Supplements | Leave a comment

Storyteller’s Creed–How do you feel about this?

Posted on October 15, 2012 by skeptvet

There’s a pretty good argument to be made that a lot of the differences between people’s opinions on controversial issues have more to do with differences in temperament and its influence on world view than with the facts or arguments related to specific conflicts. Journalist Chris Mooney has made a compelling case, based on extensive research in psychology, that our political opinions, for example, are shaped more by our temperament than our experiences. And that temperament is determined largely (perhaps 70%) by our genes.

Such a theory certainly seems to explain some of the ideological divisions in the U.S. today, and the intense and reason-proof arguments often seen around so-called “culture war” issues. It would also explain why facts and rational arguments are of so little value in challenging faith-based beliefs, both those pertaining to alternative medicine and those in other domains. Ultimately, a clash of philosophies, built largely on a clash of personalities, may underlie arguments that seem like differences of opinion about factual matters but which seem insoluble and intransigent no matter how much data is available.

Of course, this is a simple theory about a complex subject, human belief and behavior, and it may very well not be correct. Certainly, it can’t be said to be established beyond any reasonable doubt. Still, I find it intriguing and perhaps enlightening.

I ran across the credo below at an art fair last week. My own reaction to it was that it represented the kind of thinking that is behind many of the worst choices and arguments people make. Willful denial of reality in favor of what we wish were true can’t be a sound basis for decisions, in medicine, politics, or any other area involve the world outside our own minds.

I would never deny the importance and power of imagination, hope, love, or other core human feelings. Anyone who knows me will attest I am nothing if not intense in my feelings. Still, I find this set of statements naïve at best and perhaps even a little offensive. Obviously, others see it in a much more positive light. I suspect, though I can’t see any way to prove, that how one reacts to this credo might very well be predictive, to some extent, of how one views religion, alternative medicine, and other areas of conflict between reason and emotion, skepticism and faith.

I’d be interested in any thoughts or reactions to the series of principles that inspired it.

The Storyteller’s Creed

Posted in General | 9 Comments

Zoopharmacognosy–Do Animals Self-Medicate?

Posted on October 8, 2012 by skeptvet

Before becoming a veterinarian, I did a master’s degree in animal behavior, working primarily with chimpanzees. These are fascinating creatures, with many of the cognitive abilities of a young human child (and with a similar emotional temperament as well, which can be a problem in an animal far stronger than any human and equipped with large canine teeth!). One of the most interesting observations about chimpanzees in the wild is that they are sometimes seen eating plants, dirt, or other substances not part of their normal diet, substances which are thought to have possible therapeutic values in preventing or treating parasitic infestations, infections, and other medical problems. Other mammals, birds, and even insects have been seen engaging in similar behaviors, and the suggestion has been made that these creatures are, in some sense, deliberately medicating themselves, a phenomenon labeled zoopharmacognosy.

This is, not surprisingly, a popular idea among proponents of herbal medicine and other medical approaches that claim natural remedies and intuitive knowledge are central to health. However, as a skeptic I am well aware of how easily anecdotes, and elaborate theories built on them, can turn out to be descriptions of what we hope or wish to be true rather than of the world as it actually is. Humans are masters of seeing what we want to see and ignoring things that contradict our beliefs. So do animals self-medicate?

How Can We Find Out?
The first question to ask in order to explore this subject is how would we demonstrate self-medication and distinguish it from other behaviors? A variety of criteria have been suggested for identifying self-medication in wild animals. And as always in science a consistent pattern that holds up even when attempts are made to explain it with alternative hypotheses is necessary for a reliable conclusion.

Ideally, animals should be seen to seek out and ingest plants or other substances that are not part of their normal diet. They should do so only when they have some objectively identifiable marker of a specific illness. There should be some plausible explanation for why the substance ingested could potentially affect the illness the animal has (e.g. laboratory evidence that a chemical consistently found in a plant can reduce the levels of a GI parasite; NOT simply an unproven folk belief in the medicinal value of the plant). The marker of illness should consistently resolve after the animal has ingested the substance thought to be therapeutic.

Of course, all of these steps could be present and still not definitively prove self-medication, especially given that most behavior of wild animals isn’t observed, and there are many ways in which observers can skew results be selectively attending to or noting some behaviors more than others. Controlled experimentation would also be needed to rule out other explanations. This is, of course, rarely possible with great apes or other wild mammals, though some work has been done with laboratory animals and insects.

Another question to consider is what mechanism might explain self-medicating behavior if it were observed. Do animals have theories of disease, as humans do, that lead them to select specific therapies based on predictions from these theories? Do they remember or communicate to others the particular remedies for particular illnesses? Such deliberative thinking seems pretty unlikely, and there is no reliable evidence of it, despite extensive research, even in the most cognitively advanced species such as the great apes.

More likely, self-medicating behavior would be, like all other behaviors, a product of natural selection operating on underlying variation between individuals. The tendency to seek out certain tastes or smells, for example, when experiencing certain symptoms could easily be fixed by selection if doing so improved the reproductive success of individuals with genes prompting this behavior over that of individuals without such genes. Of course, such adaptive explanations can easily be manufactured for every behavior, and they need to be demonstrated experimentally when possible to be truly believable.

What’s the Evidence?

Wild Animals
In any case, what is the evidence for self medication? In wild animals, it consists largely of uncontrolled observations with a significant risk of bias or misinterpretation. Anecdotes abound, but rigorous, repeatable patterns with solid links between symptoms, behavior, and outcome have not been demonstrated. It is common to note the consumption of an unusual substance and begin looking for evidence of a medical problem to explain it, but instances of that same problem or consumption of that same substance that are not related are overlooked. This is a form of recall or confirmation bias that makes all anecdotes unreliable as evidence for a particular theory.

The medicinal value of plant ingested in such cases is often assumed based on local folk medicine practices or the presence of certain chemicals in the plant which have in vitro effects that might be relevant. The same sources of evidence are often used to validate all kinds of claims about the medicinal value of herbal remedies, and the reality often turns out to be that there is no such value. These kinds of evidence can only suggest possible relationships, not prove them.

And we have to remember that animals also frequently ingest substances that are actively harmful to them. I pull a surprising variety of potentially deadly objects out of the gastrointestinal tract of dogs and cats on a regular basis. And both domestic and wild animals have been seen to succumb to ingestion of poisons as well as indigestible foreign objects. So any theory about intentional self-medication has to also explain this self-injurious behavior. Are these animals committing suicide? Or, as seems more likely, are they mistaking harmful and inedible substances for food or exploring the world through taste and ingestion without a consistent regard for the likely benefit or harm?

There is, of course, little question that animals seek out specific tastes, smells, and colors in their food that are associated with relevant nutrients. It is reasonable, then, to suppose they might similarly seek out such cues in medicinal substances. And the distinction between food and medicine can be unclear when both are made up of substances found in nature and not processed in any significant way. So, all the anecdotes about self-medication behavior may represent an evolved behavior that reduces the burden of disease and parasitism in some individuals, conferring a selective advantage. As of now, however, this is still simply a hypothesis that has not been rigorously demonstrated.

Laboratory Experiments
More convincing evidence of self-medication is available from experimental studies in insects and laboratory animals. One such study, looking at Monarch butterflies, elegantly shows a facultative change in food source associated with parasitism.

These butterflies normally lay their eggs on milkweed. The larvae ingest the plant and incorporate toxins called pyrrolizidine alkaloids into their tissues. These act as a defense mechanism. Predators eating the distinctively colored butterflies will be nauseated by the toxins and will avoid similarly colored butterflies in the future. This doesn’t, of course, help the individual the predators eat, but it can help related individuals who carry similar genes. This is itself a fascinating and amazing example of natural selection in action.

The research study showed that butterflies affected by a certain parasite preferentially lay their eggs on a variety of milkweed which they do not ordinarily use as a food source. This variety contains a higher level of pyrrolizidine alkaloids than the one they usually lay eggs on. Larvae which hatch out on the more toxic variety and ingest its toxins have lower rates of parasitic infestation and a greater reproductive success than parasitized larvae feeding on regular milkweed.

Interestingly, there is a cost to this behavior. Unparasitized larvae that hatch on the more toxin milkweed actually have a reduced survival, so the behavior is only advantageous in the face of parasitism, otherwise it’s a bad choice for the female butterfly. This is also a nice illustration of the fact that all medical therapies, whether “natural” or not, involve balancing risks and benefits in specific circumstances.

This model shows how behavior that can be called self-medicating can evolve in the same way that food preferences evolve. It also shows that the development of such behavior doesn’t require advanced mental abilities or any mystical intuition about the healing value of plants. The trial-and-error processes of natural selection operating over long periods of time are capable of leading to behaviors that appear purposeful even though they are not.

Bottom Line
So do animals self-medicate? Iwould say the answer is a qualified “yes.”

There is good evidence that some animals have evolved adaptive behaviors which include selecting certain food sources preferentially when the individual has a medical problem that that food source can ameliorate. There is considerably less evidence that animals consistently make accurate choice about ingesting specific substances to treat or prevent specific medical conditions. The numerous anecdotes of behaviors which appear to suggest this could easily be matched by anecdotes of behaviors which are clearly self-injurious or neutral with respect to health, so any theory about self-medication has to account for both kinds of behavior.

The theory that most effectively does so is the same general theory of how natural selection shapes food preferences and other complex behaviors over time, through differential reproductive success among individuals with genes predisposing to different behavior patterns selecting for the most adaptive pattern for the current environment. Many such variations are expressed. Some are harmful or maladaptive and eventually die out, but they can be seen at any given “moment” in evolutionary time and mistaken for something that is adaptive. Some variations may hit upon a truly beneficial behavior and, over time, the genes underlying these behaviors will become more frequent in the population, as wil the behavior.

It is important to point out also that this has nothing to do with the complex theories and mythologies used to justify herbal folk medical practices. People may or may not have gotten the idea of using certain plants for treating disease from watching wild animals. Whether or not this is true doesn’t mean those plants are actually effective as medical therapies, in humans or in animals. That has to be proven in the usual rigorous, controlled, scientific way.

And there is no need to imagine a mystical intuition about the healing power of plants to explain self-medication. Butterflies can be manipulated to show such behavior under controlled conditions, and this can be easily explained by established mechanisms of natural selection, without any need for recourse to mystical explanations. Likewise, the medicinal use of natural substances by animals doesn’t suggest this is a highly effective or desirable form of medicine for modern humans. Evolved self-medication and folk medical practices were part of human behavior for millions of years with little improvement in our overall health and longevity. We are fortunate to have stumbled across methods of identifying cases, treatments, and preventive measures for disease that are far more effective even if not “natural” in any atavistic sense.

There is also ample evidence that animals, including humans, make maladaptive choices about food and medicinal substances. Animals ingest poisons and inedible foreign objects readily. And while humans have a clearly adaptive drive to seek certain nutrients which were scarce in the environment in which we evolved (like sugar, salt, and the ample calories in fat), our inability to curb our desire for these substances now that most of us have an abundance of them is the source of the most serious disease afflicting the developed world. The mechanisms of food selection and self-medication which may be beneficial in one environment, can just as easily be harmful in another. They are not drives towards health and well-being; they are specific behaviors generated by natural selection to better adapt our ancestors to a particular environment.

Posted in General, Herbs and Supplements | 11 Comments