Vitamin Supplements- Do they prevent cancer?

Posted on August 30, 2010 by skeptvet

Few purported medical interventions have such wide appeal or such an entrenched reputation for being benign and beneficial as vitamin supplements. Vitamins are chemicals (yes, they are, though you can call them “compounds” or even “essential nutrients” if it sounds nicer) that are required for normal health in minute quantities and cannot be made internally but must be obtained from the diet. Different species have different vitamin requirements, of course, so the defining characteristic is dependent on the organism, not the chemical. Vitamin C, for example, is a dietary requirement for primates and guinea pigs, but all other mammals can make enough on their own from other chemicals that they don’t require it in the diet, so it is not truly a vitamin for them.

Part of the reason vitamins are so widely believed to be good for us is the vague memory (at least in developed nations, though it is still ordinary reality in many parts of the world) of a time when vitamin deficiencies were common due to inadequate diets. Correcting such deficiencies has the kind of tangible, dramatic impact on health that antibiotics or polio vaccine can have, so it is easy to see such things as miraculous. And in America, where more is always better, the idea that it is a good idea to give vitamin supplements even to people with an adequate diet and no obvious signs of deficiencies is a naturally appealing one.

Unfortunately, the grim naysayers of science such as myself are often stuck with the thankless job of dispelling even appealing misconceptions, and recent editorial in the American Journal of Epidemiology has done that for some the proponents of vitamin supplements most hoped to be of benefit in preventing one of the major classes of illness that has replaced nutritional deficiencies and infectious diseases, cancer.

Byers T. Anticancer Vitamins du Jour—The ABCED’s So Far. American Journal of Epidemiology 2010;172:1–3.

The editorial surveys the history of anti-cancer vitamins from early reason for hope seen in observational and animal model studies through disappointing and often frightening clinical trials. In alphabetical order, then (citations are omitted and can be found in the full text of the article):

Vitamin A

Animal experimental models led us to the notion that cancer risk might be ‘‘materially’’ reduced by supplementation with beta-carotene, a retinol precursor. Although that idea was seductive, we were all disappointed when 2 large randomized controlled trials that began in 1985 in Finland and the United States reported an 18% increased risk of lung cancer caused by high-dose beta-carotene supplementation and a 28% increased lung cancer risk caused by a combination of beta-carotene and retinol. The vitamin A era was over. 

Vitamin B

Again, based on animal experimental evidence and supported by epidemiologic evidence of connections between diets low in B vitamins and increased cancer risk, a large randomized controlled trial was begun in 1985 in central China, where micronutrient deficiency was common and where rates of cancers of the stomach and esophagus were extraordinarily high. Nonetheless, several years of supplementation with a combination of riboflavin (vitamin B2) and niacin (vitamin B3) had no effect on incidence of upper gastrointestinal cancers. Interest in folic acid (vitamin B9) persisted, though, in part because of its striking effect on neural tube birth defects, coupled with speculation about possible benefits of food fortification for diseases such as colorectal cancer that were inversely associated with diets rich in folate-containing foods and supplements. However, a 7-year randomized controlled trial found that high-dose folic acid supplements actually increased risk of colorectal adenomas. The vitamin B era was over.

Vitamin C

Next came vitamin C, a popular charge led by none other than Linus Pauling, the brilliant and charismatic 2-time Nobel laureate. Of all the cancers thought to be related to vitamin C deficiency, gastric cancer led the way, and of all the places on Earth where a vitamin C deficiency correction trial might yield benefits for gastric cancer, Linxian, China, would be the best. Indeed, vitamin C was tested in the Linxian trial, but just as for the B vitamins, vitamin C produced no change in gastric cancer rates .

Vitamin D

Over 2 decades of searching for an anticancer vitamin, we had seemed to skip over vitamin D in its proper alphabetical sequence…the International Agency for Research on Cancer conducted a comprehensive review of the evidence for vitamin D and cancer prevention, concluding that vitamin D may play a protective role in colorectal cancer, but not for prostate cancer, and that the evidence is weak for breast cancer. The conclusion by the International Agency for Research on Cancer about the weakness of the evidence for breast cancer has been a source of controversy among vitamin D protagonists, but subsequent nested cohort studies have found no relation between breast cancer risk and circulating levels of vitamin D. Nonetheless, vitamin D remains the cancer-preventing vitamin du jour.

…An outstanding set of papers in this issue of the American Journal of Epidemiology reports on findings about the relation between circulating levels of vitamin D and subsequent cancer risk…These studies found no suggestion of an inverse association between vitamin D levels in the circulation and later incidence of 6 types of cancers (upper gastrointestinal, ovary, endometrial, pancreatic, kidney, and non-Hodgkin lymphoma)… The only association observed in this set of 6 analyses was a troubling one: that risk of pancreatic cancer was doubled for those in the highest quintile of circulating vitamin D levels.

…many ongoing randomized controlled trials are now using quite high doses of vitamin D. As we await clearer evidence of benefits from those trials, we will also need to be prepared to be vigilant about their individual and collective power to assess any potential harms.

Vitamin E

In 1993, we launched headlong into a love affair with vitamin E fueled by compelling observations that those who chose to take vitamin E supplements were at lower risk of heart disease. Vitamin E supplementation became the rage as several large, randomized controlled trials were mounted. When those results finally came in, the findings were again disappointing: vitamin E supplementation offered no benefit for heart disease, and it slightly increased overall mortality. In the meantime, though, because of a secondary observation that prostate cancer incidence was lower in the vitamin E arm of the same Finnish trial that tested beta-carotene (vitamin E had also been included as a factor), a large factorial trial of vitamin E (and selenium) was carried out for reducing prostate cancer incidence. Disappointment again: there was no effect of either selenium or vitamin E on incidence of prostate cancer. The vitamin E era ended in a whimper.

Of course, alternative medicine proponents often dispute this evidence, and it is easy to find claims of efficacy for all of these vitamins in preventing or treating cancer: Vitamin A, Vitamin B, Vitamin C, Vitamin D, Vitamin E.

Given the ease with which the evidence can be ignored, cherry-picked, or distorted, the underlying conclusion of this editorial is even more salient and important than the specifics of the failed promise of vitamin supplementation to prevent:

It is timely for us to now reflect on the history of the past 25 years of our alphabetical approach to studying single vitamin deficiency states as causal factors for cancer. We have learned some hard lessons along the alphabetical way. We now know that supernutritional levels of vitamins taken as supplements do not emulate the apparent benefits of diets high in foods that contain those vitamins, and we now know that taking vitamins in supernutritional doses can cause serious harm. In short, we have found that the reality of human biology is far more complex than is suggested by our simple ideas.

Let me emphasize again these key points:

1. Supernutritional levels of vitamins taken as supplements do not emulate the apparent benefits of diets high in foods that contain those vitamins.

 2. Taking vitamins in supernutritional doses can cause serious harm.

 3. The reality of human biology is far more complex than is suggested by our simple ideas.

Point 3 is one of the most important principles of science-based medicine. The understandable search for simple answers and the inevitability and challenges posed by complexity and uncertainty naturally drive us to accept simple, clear explanations and recommendations and make us shy away from the messiness and limitations of reality. But unfortunately we must accept that reality is more complex than our ideas, and that as a consequence we will often be wrong and our understanding and ability to control our health will always be limited and incomplete. The best chance we have of actually doing good is to strive for this acceptance and to deal with reality as it is rather than as we would wish it to be.

Alternative medicine often relies on the idea that belief is enough and that reality can be forced into our simple models of one cause/one cure for disease. Science can, and should do better, and though the process is slow, cumbersome, and often not psychologically comforting, the truth is that it just works better. 25 years of scientific research has shown us what supplementation of some vitamins can and cannot do for some diseases, and this information is worth the wait and the effort, and it will serve us better than the false hope and comfort of simplistic theories and wishful thinking.

Posted in Herbs and Supplements | 9 Comments

Another Acupuncture Study Shows It’s a Placebo

Posted on August 19, 2010 by skeptvet

Acupuncture is one of the CAM modalities most widely accepted as scientifically proven to be effective, at least for pain and maybe nausea. Even providers skeptical of the mystical roots and language of the practice will often suggest that it might have some real benefit. Unfortunately, the bulk of the good quality clinical research in humans doesn’t support this notion. When compared with “fake” acupuncture (needles placed in non-traditional locations or depths, retractable needles that don’t actually pierce the skin, toothpicks twirled on the skin, and so on), “real” acupuncture generally gets the same results as the fake procedure; namely a small improvement in subjectively reported pain or nausea scores. There’s no question that sticking needles in people (or mice) has measurable effects on the body (releasing various chemicals, effecting pain receptor activity, and so on). This is a long way, however, from demonstrating that sticking needles in particular places and a particular way has meaningful clinical benefits (i.e., that “acupuncture works”).

The debate about the scientific evidence for acupuncture is muddled by the lack of a consistent definition for what acupuncture actually is. Many studies claiming to investigate acupuncture actually use “electroacupuncture” (a CAM pseudonym for what scientific medicine calls TENS, Transcutaneous Electrical Nerve Stimulation). This was the case for a recent set of studies in dogs, and it is also the case for a recent study in humans:

Suarez-Almazor, M., Looney, C., Liu, Y., Cox, V., Pietz, K., Marcus, D., & Street, R. (2010). A Randomized controlled trial of acupuncture for osteoarthritis of the knee: Effects of patient-provider communication Arthritis Care & Research

Orac at Respectful Insolence discusses the study in detail. In brief, it compared electroacupuncture with “fake” electroacupuncture (needles in different spots and different amount/duration of electrical stimulation) and with a no-treatment control, and it also compared these treatments between groups of patients given high expectations of success by the providers and those given neutral expectations. The results?

Not surprisingly, there was no difference between “real” and “fake” acupuncture. Both groups reported some improvements compared to the group that got no treatment, which is exactly what you’d expect if the “real” treatment was a placebo just like the “fake” treatment. What is cool about the study is that there were several measures that differed significantly between patients given high expectations and those given neutral expectations, regardless of which treatment they got. Placebo effects are well known to be greater when the fake treatment is presented with confidence by a supposedly knowledgeable professional. In this study the way the treatment was presented to the patients affected how much benefit they got from it and mattered more than which treatment they got, just as one would expect for a placebo therapy.

Of course, real therapies will also appear to be more effective for subjectively reported symptoms if the patient is given high expectations. However, since there was no difference between the effects of “real” and “fake” acupuncture, but there was a difference caused by the expectations the patients were given, the study is a nice illustration of both the fact that acupuncture is a placebo and that expectations are a key element in achieving placebo effects.

This is of particular concern to me as a veterinarian because I believe it is impossible to influence the expectations of my patients about the benefit of the treatments I give them. So unlike humans, they are unlikely to experience any benefit from placebo effects based on expectancy. Unfortunately, their owners are very likely to be influenced by a vet presents a therapy, which leads to a situation in which the client and the vet think the treatment is helping when in fact the patient feels no better. It is this placebo effect by proxy that I think keeps many ineffective CAM therapies alive and profitable in veterinary medicine, especially since the large, well-designed studies necessary to show the underlying reality about the treatments are seldom possible due to cost and practical constraints. We need to take not of such studies done in humans and recognize the implications they may or may not have for our field given the differences between humans and our patients.

Posted in Acupuncture | 13 Comments

CAM and Advance Healthcare Directives

Posted on August 17, 2010 by skeptvet

Disclaimer: This topic strays outside my area of professional expertise, so I offer these personal musings as food for thought, not in any way as official recommendations in my role as a veterinarian.

It has become quite common these days in the United States for people to complete some form of advanced directive for health care or living will. The format and legal implications of such documents are regulated by the states and vary across the country, but in general the intent of an advanced directive is to express your wishes concerning the care you do or do not wish to receive if you are unable to make healthcare decisions for yourself, particularly in cases of terminal illness or long-term incapacitation. An advanced directive also often appoints someone to make healthcare decisions for you in accordance with the guidelines you develop in advance.

The usual subjects addressed by an advanced directive include life support care, such as mechanical ventilation and artificial nutrition, as well as palliative care such as pain control. However, it occurs to me that a common circumstance in which alternative medical therapies are employed is that in which there is no curative or definitive scientific therapy available. People reach for the implausible or the bizarre when they are desperate and unable to accept the limitations of scientific medicine or the inevitability of death. This is the kind of circumstance one might expect when someone is facing the end of life or a permanent incapacitation.

There are certainly advocates for integrating so-called complementary and alternative medicine (CAM) into hospice care for humans. And the nascent veterinary hospice movement has advocates for the use of all the usual alternative approaches as well as such truly bizarre methods such as those of pet psychics. It is difficult to know how widespread the use of CAM in the terminally ill really is, but with the growth of quackademic medicine, it seems likely that family members or other responsible agents for terminally ill or incapacitated patients who are unable to make their own healthcare choices are likely to be offered CAM therapies as part of the palliative care package.

For those of us who doubt the value, and sometimes the safety, of such approaches to medicine, it might be worthwhile to consider addressing this possibility in our advanced healthcare directives, as well as discussing it with those who are likely to be making medical decisions on our behalf should this become necessary. As the horror of the “Gonzalez Regimen” study illustrates, alternative approaches to serious disease can be more (or less) than simply ineffective. They can actively worsen the suffering of terminally ill patients. If the purpose of an advanced directive for healthcare is to protect oneself from unwanted treatment, and presumably the attendant suffering, then CAM is a group of treatments one might wish to protect oneself against.

One difficulty with addressing alternative therapies in an advanced directive would be defining them accurately enough to be useful to providers and family members making treatment decisions. Alternative medicine can be tricky to define, and one must be careful to distinguish between nonsense therapies that are either untestable or have already been falsified, and the kind of plausible therapies with limited supporting evidence that are sometimes the focus of clinical trials sought out by the terminally ill, or that are used prior to definitive scientific evidence concerning their safety and efficacy under “compassionate use” rules. The best approach might be a general definition with a list of examples, which would provide at least some guidance to decision makers. My own advanced directive contains the following statement:

I specifically refuse any treatments in the general category of “alternative medicine” which have not been validated by appropriate scientific research, including but not limited to the following: acupuncture, chiropractic, homeopathy, reiki or therapeutic touch, traditional Chinese Medicine therapies, Ayurvedic therapies, naturopathic therapies, and dietary, herbal, or nutritional therapies not supported by substantative clinical research evidence. This is not intended to exclude experimental therapies used within the context of properly regulated clinical trials or compassionate use guidelines at the discretion of my appointed healthcare agent.

This is undoubtedly an imperfect statement, and probably painfully imprecise to the ears of any lawyer, but it conveys the gist of my wishes, which is as much as such a document can be expected to accomplish.

I don’t intend to suggest that the use of CAM therapies is as pressing an issue for the terminally ill or incapacitated as questions of how intensive and prolonged life-support measures should be, or how we should palliate the discomfort of the dying. But despite the widespread presumption that such therapies are benign at worst, and possibly even beneficial regardless of the evidence, the reality is that unproven or clearly bogus alternative treatments can be harmful. They can harm patients directly, and they can provide false hope or a mistaken sense that the patient is being properly treated, which can interfere with the use of truly effective palliative therapies. In light of this, it seems worth considering the issue of CAM use when planning for the possibility that you may someday not be able to articulate your wishes concerning the care you are given.

Posted in Law, Regulation, and Politics | 3 Comments

Consumer Reports–The Dangers of Supplements

Posted on August 9, 2010 by skeptvet

There is an article in the upcoming issue of Consumer Reports discussing the sorry state of regulatory oversight for dietary supplements, herbs, and vitamins, and some of the concrete harm that has come to consumers as a result. It is encouraging to see the mainstream media recognizing that the marketing of such supplements is full of misinformation and that there is real danger in the inadequate regulatory system currently in place.

According to the industry publication Nutrition Business Journal, Big Supplement sold $26.7 billion worth of its products last year. However, according to the relatively neutral, though perhaps sometimes a bit too charitable in its interpretation of the evidence, Natural Medicines Comprehensive Database, only about a third of the 54,000 products in the database have any scientific evidence concerning safety and efficacy. And nearly 12% (over 6000 “medicines”) have known problems with safety or quality control. This is a pointed reminder that when talking about supplements, we are not talking about natural products proven to be safe and effective and provided out of altruistic motives to people not well served by the conventional “disease industry.” We are talking about products containing chemicals with poorly understood effects on the body and products which may or may not contain what the label claims is in them. And we are also talking about large profit-making corporations capable of manipulating politicians and the law to avoid appropriate regulation of their industry and both willing and financially able to vigorously defend themselves in court against people hurt by their products.

The Consumer Reports article points out that contamination of supposedly natural supplements with toxins, such as heavy metals, and with prescription drugs, is a serious danger due to the exemption of the supplement industry from the quality control regulations the FDA applies to pharmaceutical companies and other providers of medicines and healthcare products. Many of the most harmful products and ingredients come from China, which has abysmal quality control and is not in any way under the supervision of any trustworthy regulatory or watchdog organization.

The article also gives several examples of specific products that have harmed consumers, and the complete denial of responsibility on the part of manufacturers. The notion that these companies and their products differ from the mainstream pharmaceutical industry, beyond being less effectively supervised and regulated, is belied by these kinds of problems. Even the regulations that do exist concerning such products are rarely enforced, and vigorously opposed by the supplement industry. When the FDA attempted to ban ephedra, it took years of legal maneuvering despite thousands of cases of suspected illness and death from the ingredient. This has discourage the FDA from attempting to invoke it’s regulatory authority, especially in the anti-regulation atmosphere of the last administration.

And unlike Big Pharma, for most of the time since the relevant legislation (DSHEA) was passed in 1994, Big Supplement companies haven’t even been required to report serious adverse events associated with their products to the FDA. And the reports that now come in are rarely made public. So it’s not surprising that consumers, and many health care providers, have little idea how dangerous these products can be. Of course, mainstream pharmaceuticals have their dangers, but at least we have some idea what they are and some reason to think they may have benefits which justify the risks.

The article lists an even dozen supplements to be specifically avoided due to known hazards. It also lists a number it considers safe and likely effective.  I would quibble a bit with these lists. The “bad” list is a bit arbitrary and incomplete, and it ignores the danger of the nearly complete ignorance concerning the safety and efficacy of most supplements. And the “good” list includes a couple of products (e.g. glucosamine and St. John’s Wort) which are listed as “likely effective” despite pretty clear evidence they are ineffective. But these are relatively minor objections given the vital importance of having a mainstream consumer group address the serious problems in the supplement industry and advocating for better consumer protection.

Not surprisingly, Big Supplement rejects the conclusions and advice in the article, cherry picking facts to present a misleading image of the industry as benevolent providers of safe products. Their rebuttal, weak as it is, is further undercut by the presence on the same page of a banner reading “Grassroots Victory: Congress rejects expanded FTC powers.” Clearly, despite their own propaganda, Big Supplement is as interested in protecting their prerogatives and profits as Big Pharma or any other for-profit industry. This is to be expected. What is harder to understand is why we continue to let them guard the henhouse.

Posted in General | 2 Comments

Special Challenges of Science-Based Veterinary Medicine

Posted on July 29, 2010 by skeptvet

The following is a post I contributed to the Science-Based Medicine blog.

On this site there have been several thoughtful posts (e.g. by Dr. Atwood and by Dr. Novella), and subsequently much heated commentary, on the distinction between Evidence-Based Medicine (EBM) and Science-Based Medicine (SBM). I agree wholeheartedly with the position that the two are not mutually exclusive, and that SBM is essentially EBM as it should be practiced, with a comprehensive consideration of all relevant evidence, including the subject of plausibility. As a practicing veterinarian, and an officer of the Evidence-Based Veterinary Medicine Association (EBVMA), I am keenly interested in bringing to my profession a greater reliance on high quality research evidence and sound scientific judgment, and reducing the reliance on individual practitioner intuition and experience in making clinical decisions. However, those of us in veterinary medicine face some special challenges which make the subtle but important distinction between EBM and SBM especially salient. 

Where’s the Evidence?

The first of these challenges is the paucity of high quality clinical research evidence. As an example, in his 2007 book Snake Oil Science, R. Barker Bausell examined the research evidence concerning the use of glucosamine as a treatment for osteoarthritis in humans. He was able to analyze the strengths and weaknesses of a Cochrane Review which included 20 studies with 2570 patients (the most recent revision of this review includes 25 studies with 4963 patients), a NEJM study with 1583 patients, and an Annals of Internal Medicine study with 222 patients treated for two years. His conclusion was that the intervention was not more effective than placebo.

I recently did a targeted search of the PubMed literature database for a brief evidence-based medicine feature on the subject of glucosamine and chondroitin as treatment for osteoarthritis in dogs, currently in press at the Journal of the American Veterinary Medical Association. A search of the terms “glucosamine,” “arthritis,” and “dog” yielded eight references, of which three were relevant (a more comprehensive search strategy yielded sixteen references, but only the same three were relevant to the clinical question). The three useful references included two clinical trials involving a total of 113 dogs and each lasting about 2 months, and a systematic review of treatments for canine osteoarthritis which evaluated one of these two clinical studies. Predictably, the larger, better designed trial with objective measurement criteria showed no benefit of glucosamine, while the smaller, less well-controlled trial with only subjective criteria and a 23% dropout rate in the glucosamine group showed some benefit at some assessment points.

Where’s the Money?

Glucosamine is an extremely popular, and profitable, supplement routinely recommended by veterinarians and administered by owners to their geriatric dogs. Yet the clinical trial evidence concerning its effects is nearly non-existent. The depth of the evidence is no better for many, many routine clinical interventions in veterinary medicine. The primary reason for this is simple: money. 

Obviously, the health of companion animals is not as high a societal priority as human health. Many countries have little or no formal companion animal medicine at all, of course, much less high quality, evidence-based pet medicine. And even in the developed world, the absolute size of the veterinary medical profession and associated industries is dwarfed by that of the human medical industry. 

In the United States, surveys show that most dog and cat owners have come to consider their pets to be members of their family, and their willingness to pay for veterinary care has increased along with this shift in attitude. The same appears to be the case in Europe and other developed nations. This has allowed the quality and technological sophistication of veterinary care to increase. 

Pharmaceutical companies have followed this trend, increasing their financial investment in their own internal research activities, as well as funding the lion’s share of companion animal health research generally (with all the ethical and practical problems that creates). Pfizer, the largest fish in the “Big Pharma” pond, claims to spend $300 million annually on veterinary research globally, for both companion and agricultural animals. However, the company is expected to spend $9-$9.6 billion this year on its human research and development. The same pattern is true of government research spending. Veterinary medicine will always be the poor stepchild of medicine, and we cannot expect to have anything close to the quantity or quality of research evidence available to MDs trying to practice evidence-based medicine. 

A Pack of Lone Wolves?

Another barrier to effective utilization of research evidence in veterinary medicine may be demographic and cultural. In the United States, the average veterinary practice has fewer than three veterinarians, and between one-third and one-half of veterinarians are self-employed practice owners. And most companion animal veterinarians are general practitioners, only about 10-15% of practicing vets being board-certified, with the extended academic training and, hopefully, greater awareness of and respect for research evidence that might be expected to come from this training.

As a profession, we veterinarians tend to be entrepreneurial, self-reliant, and independent. This contributes to a reluctance to let anyone tell us what to do, which may be how veterinarians perceive the position of evidence-based medicine. There is no solid data on the subject (though I am involved in a survey study which will hopefully provide some soon), but in discussions with colleagues I have sensed a great deal of anxiety about the notion of “cookbook medicine” which disdains the hard-won wisdom and experience of the individual clinician. Veterinarians are reluctant to accept the idea that there may be broadly applicable standards of care they ought to adhere to, even if their personal judgment conflicts with the evidence for these.

Undoubtedly, our colleagues in human medicine share a similar temperament and similar sorts of anxieties about “cookbook medicine”. However, these may be tempered to some extent by more widespread advanced training, more structured and supervised practice environments, and greater assessment and monitoring of outcomes, which may partially explain the greater acceptance of EBM in the human medical profession. And though the case of Dr. Rolando Arafiles, Jr. illustrates the weaknesses in the systems for monitoring physician behavior, I think it is clear that the influence of government regulation, and the threat of litigation, give the concept of adhering to a recognized medical standard of care far greater teeth in the field of human medicine than it has in veterinary medicine.

SBM, EBM, or OBM?

So how does this relate to the difference between SBM and EBM? Well, traditionally the scarcity of clinical trial evidence has led veterinarians to practice primarily opinion-based medicine. Personal experience and intuition and the opinions of individual experts or mentors are the predominant foundations for clinical decision-making. There is little or no outcome assessment, so veterinarians must rely on their own clinical experience to judge whether their practices are effective. 

The negative consequences of these strategies are many. There is dramatic inconsistency in the diagnosis and treatment of even common diseases. I routinely have to explain to my clients that if they ask ten vets a question, they are likely to get seven or eight different answers. You can imagine how frustrating this is for them, and how little confidence it inspires in our expertise.

OBM Leads Kids to the Hard Stuff, FBM!

As most readers of this blog likely already know, there are many reasons why individual judgment is an unreliable guide to the true efficacy of a medical intervention, and why we should be reticent to entirely trust our own intuitions and experience. But opinion-based medicine is also a “gateway drug” to faith-based medicine, otherwise known as complementary or alternative medicine. If you are accustomed to judging the safety and efficacy of interventions on the basis of the cases you have seen personally or the opinions of “experts,” you are more likely to be persuaded by the individual experiences of clinicians promoting and alternative practice, and more likely to think that giving it a try yourself is the most reliable way to know if it really works or not. 

The Internet abounds with holistic veterinarians who claim they started their careers as scientific, skeptical doctors but that their frustration with the limitations of mainstream medicine and the problems they could not solve led them to experiment with, and ultimately become promoters of, faith-based miracle therapies of every kind that share no theoretical or practical features in common other than being validated primarily by testimonial and not consistent with scientific knowledge or evidence. 

Tooth Fairy Science exists in veterinary medicine, but it is less of a problem than the simple lack of research evidence and the consequent reliance on even less trustworthy forms of evidence. So veterinary medicine needs a science-based approach even more desperately than human medicine because we have so little clinical trial evidence to rely on, and so few resources to generate more and better evidence. The tragedy of money and talent wasted on studying therapies that have vitalist theoretical foundations inconsistent with established scientific knowledge is even more poignant in the relatively impoverished world of companion animal medical research. Plausibility must play an important role in deciding how we allocate the scarce resources we have in order to maximize the useful information we can generate, and the subsequent clinical benefits for our patients.

Towards a One Health Approach

Veterinarians must also take advantage of the evidence that our colleagues in human medicine have generated for us. There are serious dangers in extrapolating research evidence across species, of course, but we cannot afford to entirely ignore the wealth of human medical research that is relevant to our patients. Examined cautiously and judiciously, this data can help us target our own research efforts more efficiently. Just as animal models have an important role, despite their limitations, in human health research, so human clinical research can inform veterinary medicine. As clinicians, we can make more science-based decisions, even when relevant veterinary research is lacking, if we are aware of the research in humans that already exists on the conditions and interventions we are considering. 

If glucosamine is shown to be no more than a placebo after years of research in thousands of people, how much money and effort should we invest in studying its effects in dogs? And how strongly should we promote it to our clients, the vast majority of whom must pay for their pet’s care out of pocket, without insurance coverage, and who commonly must eschew needed care or even euthanize their companions for want of money to pay medical costs?

A Worthy Goal

There has been a steady growth in the quality and sophistication of care available to companion animals in the last several decades, and I am hopeful that this will continue. But I believe the interests of our patients and clients will be best served if the care we provide is as soundly science-based as possible. And while I think evidence-based medicine can become the standard in the veterinary field, with beneficial effects on the quality of the care we provide, we need the additional features of the science-based medicine approach even more than our MD colleagues: a respect for the importance of plausibility in allocating research resources and an understanding of the need to integrate all relevant evidence when making clinical decisions about interventions in the face of a scarcity of high quality clinical trial research. 

Despite all the histrionic accusations of some alternative medicine advocates about mainstream veterinarians being tools of the pharmaceutical industry or reluctant to accept unconventional approaches only out of closed-minded prejudice or a fear for our income, the reality is that we care deeply for our patients and want to provide them with the best care we can. I truly believe, and I hope the profession as a whole will come to accept, that science-based medicine is far more likely to help us do so than the opinion-based medicine we have traditionally relied on.

Posted in General, Science-Based Veterinary Medicine | 21 Comments

Double Helix Water: More Magic Water Quackery

Posted on July 20, 2010 by skeptvet

The beauty of pseudoscience as a marketing tool is that it is, for those not trained in the particular branch of real science being mimicked, almost indistinguishable from the real thing. Of course, many of the warning signs of quackery are often present, especially claims of revolutions or “paradigm shifts” that overturn well-established science, claims of a single cause or cure for many unrelated diseases, the presence of the Quack Miranda Warning, and naturally lots of testimonials with a conspicuous absence of real evidence published in legitimate scientific journals. But it is easy to see why the use (misuse, really) of scientific terminology, often by people with legitimate (though irrelevant) scientific degrees, can be quite convincing even if the idea or product being marketed is completely bogus.

Our latest example has all this and much, much more! Meet the revolution in veterinary medicine that is Double Helix Water! What is Double Helix Water? Here’s what the “inventors” and promoters of this product say:

Double Helix Water™ is solely ultra-pure H2O but we believe it is H2O in a hitherto undiscovered fundamental “phase”; not liquid, ice or vapor “phase” but a molecular solid phase even at room temperatures.…this “phase” may be the key to many of the body’s inherent healing properties thus explaining many of the mysteries of alternative health practices. They demonstrate through rigorous scientific experimentation that water can form a solid particle at room temperature. The discovery of this particle then, begins to unravel the mystery behind the differences between allopathic and homeopathic medicine as we know it.

Ahhh, so there is a connection with homeopathy, eh? Well, sort of. the promoters certainly claim their “discovery” explains the powerful effects of homeopathy (which they seem to take as a given, despite the strong, consistent evidence that homeopathy is no better than a placebo). However, there is no talk of the Law of Similars, Dilution and Sucussion, which are core theoretical concepts behind orthodox homeopathy, so one wonders exactly what the connection is beyond the absence of anything but water in this product and in homeopathic remedies. Despite this, the forward to the promoters’ book on their product states clearly that the “discovery” takes,

the concept of homeopathy into the twenty-first century…Their demonstration of microscopic clusters in water is groundbreaking and revolutionary! Their purification of water, with the atmospheric purity described, places homeopathy on a scientifically valid foundation that is equal at least to the discovery of atomic energy.

What Are the Claims?

On another site devoted to this product, the promoters first weasel out of any liability or fraud allegations by stating,

It is not a drug or a curative agent (medicine) in any respect. [We] are not medical doctors and we want all to know that we make no representations that this water treats or cures anything, period….let’s all be careful about how we introduce this discovery to the world: Do not make claims, please! This water does not “cure” cancer, does not “cure” diabetes—it does not cure anything. It is not a drug; it is not a medicine. It is simply water…

Disclaimer out of the way, they then merrily go on to say

It is our belief that this phase of water is a central agent in the arsenal of the body’s immune response….we theorize that these particles are the molecular basis for what Chinese Medicine has suggested for over two thousand years: that an electrical matrix surrounds the body and this electrical matrix is the senior dominating factor in all health issues….Therefore it is very feasible that we have found a material basis for the Chinese meridians.

Wait, I thought their “discovery” proved the scientific basis of homeopathy. So, it also proves the scientific basis behind Traditional Chinese Medicine? Wow! Anyway, on to more medical claims:

….have numerous MDs and scores of other healthcare professionals recommended this new phase of water to their clients, patients and family members for a healthy lifestyle? Absolutely. If one is a rational, sane individual and witnesses large numbers of people with many varied health problems experiencing remarkable changes in their wellness, something occurs deep inside oneself. It becomes more a crusade than a research line. And the people whose lives have been saved or changed greatly for the better want others to know what they think of this water—so the word spreads.

And not to leave out the important (and potentially lucrative?) veterinary sector, the promoters of Double Helix Water provide some additional endorsement on this site from a paragon of the holistic hodgepodge school of veterinary medicine, Dr. Deva Khalsa, who says:

I have found Double Helix to be a cutting edge product that works deeply to heal my canine and feline patients. I’ve found it helpful in cases of arthritis, autoimmune disease, cancer and diabetes along with other medical problems.

The folks marketing Double Helix Water, clearly have a philosophical agenda that goes beyond their claims of mere scientific interest in the nature of water, or even the possibly genuine belief that anecdotes and testimonials have really shown it to be useful. This is clear from the preface to their book, which contains a remarkable number of quack warning signs efficiently packaged in a small space:

 The Secret of Life has been the foundation of philosophy and medicine throughout history. The Chinese called it chi; the Japanese, qi; the Indians, prana; and Wilhelm Reich, orgone. Much of medicine before 1940 was rather pragmatic empirical practice with many errors. Since 1940 the bulk of modern medicine has been a takeover by the PharmacoMafia—my title for the pharmaceutical industry. Today Modern Medicine is at least the third leading cause of death in the United States (JAMA, July 2000). Drugs that have little justification and serious risks, called side effects, are added almost daily to the stream of offerings. Numerous brave souls question the current system, and yet it is THE SYSTEM rejecting and attacking viciously virtually every alternative.

Nothing as inspiring as an open-minded individual disinterestedly pursuing the greater good of all, eh? Well, perhaps not entirely open-minded philosophically, as this passage illustrates. What about disinterested? Well, let’s not forget that even though it’s “just water,” they aren’t exactly giving it away. Here’s the “bottom line” from one of their two official vendors, Dr. Khalsa:

One bottle of Double Helix Water™ (a three months supply) at an average usage price of $1.22 a day – $109.95

One bottle of Double Helix Water™ (a two months supply) at an average usage price of $1.33 a day – $79.99

Special Subscription Pricing Offer – Receive a three month supply every three months at an average usage price of $1.12 a day – $99.99

Who’s Behind It?

Interestingly, two of the promoters, David Gann and Dr. Shiu-Yin Lo appear to have a long history of selling dubious forms of magic water. Dr. Lo was Director of Research and Development for American Technologies Group (ATG) in the 1990s. He claimed to have discovered another form of structured water with elements called “IE crystals” in it, which was marketed in the form of a detergent-free cleaning product called a “laundry ball” and also an automobile engine performance enhancer called The Force. According to one source, these products were investigated by the Oregon Department of Justice and determined to be fraudulent, and the company paid a fine and eventually closed down. Affidavits from a an independent analytical laboratory and a professor of chemistry at the University of Oregon were submitted refuting the company’s claims about IE crystals, and the DOJ concluded that these claims were not supported and not consistent with appropriate scientific practices. David Gann was the Director of Marketing for ATG.

Dr. Norm Shealy, who wrote the preface to the marketing book about Double Helix Water, is a committed proponent of Hodgepodge Holism on the human side, including spiritual and prayer healing, hormones and all manner of supplements, energy medicine, and a wide variety of unproven and quack therapies. All three of these individuals obviously have lifelong personal, and financial, commitments to bogus medical therapies.

And there is the veterinary face of Double Helix Water, Dr. Deva Khalsa. From her web site, she subscribes to any and all forms of alternative therapy grouped, for no obvious reason, under the label “holistic.” Acupuncture, homeopathy, herbal therapies, chiropractic, applied kinesiology, prolotherapy, energy medicine, hair analysis, all sorts of supplements, and of course Double Helix Water. Dr. Khalsa will even consult and prescribe these remedies by phone, which is certainly a more convenient way of assessing your pet’s needs than a bothersome in-person visit or physical exam.

What About the Science?

So, what about this “scientific breakthrough”? Any chance it’s real? Well, not being an expert in physics or chemistry, despite some training in those fields, I can’t evaluate the underlying theory very extensively. Of course, neither can the doctors who believe in the remedy, despite their glowing testimonials and deep faith. Those of us who practice science-based medicine are sometimes at a disadvantage since we cannot as blithely dismiss the claims we haven’t investigated or understood thoroughly as easily as those who practice faith-based medicine can affirm them without investigating or understanding them. However, there are some with the appropriate expertise who do dismiss the claims about “structured water” in general, including a product previously “invented” and sold by one of the promoters of Double Helix water. Apart from the affidavits and analyses submitted in association with the fraud investigation of ATG, there is an entire web site devoted to structured water quackery, provided by a former professor of chemistry, Stephen Lower.  Apparently, there is an entire industry built around claims that manipulating the atomic or molecular properties of water can solve all your health problems. Dr. Lower mentions Dr. Lo’s claims about IE crystals and points out that the only scientific publication concerning these claims was in a journal, Physics Letters B, that does not require reporting the details of one’s methodology and has minimal peer review, so it is difficult to assess the quality or reliability of the data presented. The findings have been challenged on practical and theoretical bases both by Dr. Paul Engelking, the author of the affidavit in the ATG case (here) and by Steven Bittenson, a physicist who is actually a proponent of homeopathy (here). Another paper of Dr. Lo’s, on so-called “stable water clusters” and presented on the front page of the Double Helix Water website (here) is from the companion journal Physics Letters A. No other journal appears willing to publish Dr. Lo’s claims about water, which should be cause for some skepticism about them.

Dr. Lower provides lengthy discussions on his site of the science, and pseudoscience, behind “structured water,” and while my expertise only permits me to say with confidence that the medical claims for Double Helix Water are implausible and without any real evidence to support them, Dr. Lower cogently argues that the same is true of the underlying physics and chemistry claims made by the inventors of this wonder product.

So in essence we have a group of individuals dedicated not only to theories and practices which are improbable and not supported by solid evidence or accepted by mainstream science, but also with a long history of trying to make a living selling products based on these theories. The perfect storm of cognitive dissonance, philosophical bias, and financial self-interest to prevent any rational consideration on the part of the promoters that they might be mistaken. The result is yet another unproven and most likely thoroughly useless product sold to people who only want the best for their sick pets, and most often to those whose animal companions have serious medical problems for which highly effective real therapies don’t exist. Empty promises and false hope, for only $79.99-199.99 per bottle (plus shipping and handling).

Posted in Miscellaneous CAVM | 145 Comments

Supraglan: Empty Promises, Not Medicine

Posted on July 14, 2010 by skeptvet

I came across an especially egregious example of veterinary quackery recently which I wanted to warn people about. Petwellbeing.com, a subsidiary of the Canadian company Natural Wellbeing Distribution sells a product call Supraglan, which it advertises as a treatment for Cushing’s disease (hyperadrenocorticism). Cushing’s disease is a serious, chronic disease in which the body produces excessive steroid hormones, which have a variety of deleterious effects on many different body systems. It is usually caused by a benign tumor in the pituitary gland in the brain, which tells the adrenal glands to make too much of their normal steroid products. Some cases are caused by a tumor of the adrenal glands, which is almost always an aggressive, highly malignant cancer. The symptoms of Cushing’s disease can be created by chronic use of steroids given to treat other diseases, but this is a different condition in that if the patient stops getting the drugs then the symptoms will resolve.

The PetWellbeing website offers a brief, and inaccurate, description of the disease and then claims their product:

is gentle yet effective, safe for long-term use without adverse side effects…Supraglan is designed to restore your pet’s quality lifestyle and to increase life expectancy by reducing thirst and regulating elimination (liver/kidney and digestive); balancing blood sugar levels (endocrine); increasing muscle use and ability (anti-inflammatory); protecting against infection (immune); and by promoting a healthy skin and coat (natural herbs)

Of course, to cover their behinds legally, the company includes the Quack Miranda Warning on their page acknowledging that the FDA has not approved the product for what they are selling it for, but this is intended to apply only to products that are making so-called “structure and function” claims, meaningless and unscientific statements that the product “supports” some body system, not that it treats or prevents an actual disease. So the treatment claims are illegal to begin with since the drug is not FDA approved as a treatment for Cushing’s disease.

Unfortunately, even the minimal restraint showed by the actual manufacturer is not found on other web sites promoting this snake oil. One site states, “There are many similarities between the symptoms of Cushing’s Disease and Addison’s Disease in dogs–both considered fatal in canines. There are many rumors in regard to the miraculous healing of the natural supplement Supraglan, reported to cure both diseases.” Addison’s disease is a lack of adrenal steroid hormones produces by destruction of the adrenal glands. It is, essentially, the opposite of Cushing’s disease, and yet Supraglan is reported to cure both! How does it accomplish this miracle? Apparently, it uses, “natural ingredients to decrease the adrenal system in dogs from a completely hyperactive state, the product slows the overproduction of the corticosteroid hormones which have become overloaded in the dog’s system.  Side effects have not been seen yet in the usage of Supraglan.”

So a natural, side-effect free cure for Cushing’s disease and it’s opposite. See any warning signs of quackery yet? So what’s in this miracle elixir?

  • Borage: contains natural precursors of adrenal glands hormones; supports endocrine system functions; helps with detoxification; supports adrenal cortex.   
  • Astragalus: tonic; nutritive; supports liver function; helps maintain immune system.
  • Bistorte: astringent, soothing, anti-inflammatory, has a tonic effect on liver and kidneys.
  • Eleutherococus Senticosus: helps maintain normal hormonal actions (ACTH and cortisone) on adrenal glands; supports the immune system.
  • Wild Yam: natural inflammation management; contains steroidal saponins (dioscin, dioscorin) used as sources of saponins in the preparation of steroid hormones.
  • Licorice: adrenal supporting (contains glycyrrhizin, a compound similar to corticosteroids); immune support; anti-inflammatory.
  • Dandelion: highly nutritious food; supports liver function, digestion and appetite.

Ok, now here’s the tough part. What’s the evidence to support these dramatic claims? You guessed it–reams of testimonials from “satisfied customers” and not one single research study of any kind. Some of the claims for the specific ingredients are found in reference guides to herbal therapy, usually based only on tradition or limited suggestive in vitro or lab animal studies. A search of the usual source, including Pubmed, Cochrane Reviews, even the National Center for Complementary and Alternative Medicine, which is quite friendly to herbal medicine in general, turned up not a single study that lent any support at all to the idea that these ingredients, individually or in combination, are a safe and effective treatment for Cushing’s disease.

I did find a few studies suggesting why some of the ingredients might be a bad idea to use in these patients. Licorice is known to cause pseudohyperaldosteronism, a hormonal imbalance which messes up the levels of sodium in the blood and can cause high blood pressure and even interfere with proper diagnosis of adrenal disease. Wild yams have been thought to increase some steroid hormones, and so have been used as a treatment for menopausal symptoms, but in reality it does not actually increase steroids, and its apparent effects on symptoms was likely due to adulteration of commercial yam products with synthetic hormones

There probably are some in vitro or lab animal studies, maybe even a small human clinical trial or two, that might have some suggestion of some potential effects on the adrenal hormone system. After all, herbs are essentially drugs, though usually unpurified and inadequately standardized and tested, so they likely do have some effect. I would be interested in any such studies any of you are aware of, but I can promise you there is nothing that would justify selling pet owners whose dogs have a serious, life-threatening disease, this concoction with claims that it will cure them or even meaningfully improve their quality of life. Testimonials, tradition, and blind guesswork based on in vitro studies are not sufficient to make such claims or profit from people with sick animal companions.

I expect I will now receive the usual angry comments of the following sort:  “Who do you think you are?! I used it and my dog got better so you’re stupid! You’ve just been bought by Big Pharma to push their toxic drugs!” I have received such comments following previous posts on similar nostrums such as Neoplasene, Yunan-Paiyao, and so on. I don’t expect to be able to head these off, but I will try to save myself some time later and make a few points:

1. For reasons discussed at length here and anywhere critical thinking is respected, anecdotes are not proof, only suggestions of areas to study more formally. A million people are capable of being wrong as easily as one, so if you believe my assessment of this product is incorrect, show me real evidence, not testimonials. The hierarchy of evidence is the best guide to what is real evidence and what isn’t, if there is any doubt.

2. I make my living practicing medicine, and that includes treating Cushing’s disease. This has nothing to do with my objections to this product. If there were proof it worked, I would use it just like I use conventional treatments now. And don’t forget the folks making and selling this have a financial incentive to promote its use the lack of evidence it works that is far greater than any incentive I have to discourage its use. I am motivated by a belief that evidence and the truth serve my patients and clients better than false hope and misleading marketing.

3. I am not closed-minded, dogmatic, and I am happy to change my mind if the evidence warrants it. Being skeptical doesn’t mean disbelieving things automatically. It means withholding judgment until the facts are in. There are almost no facts to base a judgment on here, so the burden of proof is on those making wild claims (and a profit) on the product, not on those of us pointing out there is no good reason to think it works.

Posted in Herbs and Supplements | 164 Comments

The History of Veterinary Acupuncture: It’s Not What You Think

Posted on July 11, 2010 by skeptvet

One of the most common arguments made in support of using acupuncture on animals is that veterinary acupuncture is an ancient art practiced and refined in China for thousands of years. On one website providing referrals for acupuncturists, the claim is made that,

Acupuncture has been used on animals for over 4000 years. Legend has it that veterinary acupuncture was discovered when lame horses used in battle were found to become sound after being hit by arrows at distinct points. In any event, there is evidence that Chinese “horse priests”, the caretakers of the army’s horses, practiced acupuncture during the Zang and Chow Dynasties around 2000-3000 BC.

Similarly, the International Veterinary Acupuncture Society (IVAS) website claims,

Acupuncture may be defined as the insertion of needles into specific points on the body to cause a desired healing effect. This technique has been used in veterinary practice in China for at least 3000 years to treat many ailments. The Chinese also use acupuncture as preventive medicine against such problems as founder and colic in horse.

Of course, the notion that the length of time a methods has been in use is somehow proof of its safety or efficacy is fundamentally unsound. Unsafe and ineffective treatments (bloodletting, various forms of burning or “cauterization,” faith healing and, I would argue, acupuncture) often endure for centuries, even millennia despite having no benefits and even being harmful, due to the many, many reasons people are prone to making inaccurate judgments about such things. Even if acupuncture has endured for thousands of years, it has failed in all that time to extend our life expectancy, reduce infant and childbirth mortality, eliminate any infectious disease, or accomplish any of the other dramatic improvements in human and animal health scientific medicine has given us in the last 200 years.

Still, it is understandable why people might find the tenacity of a method to be a strong argument for it being effective. Unfortunately, in the case of veterinary acupuncture, the appeal to longevity argument is not only misleading, it doesn’t happen to even be true!

A recent article in the German science history journal Sudhoffs Archiv makes a strong and detailed case that most of the sources cited to support the argument that the Chinese have practiced acupuncture on animals for thousands of years are actually describing bloodletting and cauterization practices that have no meaningful relationship to what is considered to be acupuncture today. The authors also argue that many of the veterinary techniques these Chinese sources describe using on horses correspond closely to techniques found at the same time or even earlier in Greek, Egyptian, Arabic, and Indian sources, and that they may have derived originally from Western practices or had common sources. The article’s authors include two professors of East Asian history and an equine veterinarian, Dr. David Ramey, who has written extensively on equine medicine in generally and on complementary and alternative veterinary medicine.

Buell PD, May T, Ramey D. Greek and Chinese Horse Medicine: Déjà vu All Over Again. Sudhoffs Archiv. 94(1);2010:31.

According to the authors, the earliest written records of Chinese veterinary medicine, from the 3rd century BC, concern primarily herbal treatments. By the 6th century recommendations concerning bleeding and cauterization are found, though herbal therapies are still the primary treatments recommended for animals. The earliest surviving Chinese text specifically devoted to veterinary medicine dates from 1384, though much of the material it contains appears to have originated in the 11th and 12th centuries. none of these early texts refer to anything that could be considered acupuncture in the modern sense. The IVAS defines acupuncture as, “the insertion of needles into specific points on the body to cause a desired healing effect.” Though there are a variety of techniques, including using heat, laser light, and electricity on supposed acupuncture points, most commonly veterinary acupuncture takes the form described by the Australian Veterinary Acupuncture Group: “Acupuncture is the technique of using very fine needles that pierce the skin at specific points in order to treat or prevent disease.”

There is no evidence for such techniques in the early Chinese veterinary texts. Though the term “zhen” used in such texts is often incorrectly translated as “acupuncture,” it is clear from a thorough reading of these texts that the term was used to refer to bleeding, cauterization, and even surgical interventions, not acupuncture as applied to people and animals today. Such interventions become more prominent in later Chinese veterinary texts, however these texts also do not describe anything that can be reasonably called acupuncture. Methods resembling modern veterinary acupuncture apparently were not widely practiced in China until the 1960s.

The historical Chinese texts do describe specific interventions at specific points on the body of the horse, and they include detailed charts and diagrams to guide these interventions. Such charts are often presented in modern works, without translation of labels or inclusion of accompanying text from the original works, as evidence of historical acupuncture point designations. Actually reading the text associated with such diagrams makes it clear that these are not charts showing acupuncture points or meridians. In reality, most such charts for animals date back no further than the 1970s. (For a more detailed look at the history of veterinary acupuncture, see Dr. Ramey’s book Complementary and Alternative Veterinary Medicine Considered).

The authors of the Sudhoff Archiv article also describe some of  the remarkable similarities between Chinese veterinary practices and those described in Greek, Roman, and other Western cultures. I don’t have the expertise to judge the plausibility of their suggestion that some of this similarity may be due to the spread of ideas from the West into China via Arab or Indian sources. Though I would not be at all surprised if disparate cultures came up with very similar theories about unseen forces responsible for disease and methods of manipulating these forces, it is an interesting hypothesis that the similarities are more direct.

Overall, the article is a detailed scholarly look at the truth about early Chinese equine medicine, and veterinary medicine more generally. It is particularly helpful in challenging the many inaccurate claims about the antiquity of veterinary acupuncture. While I do not believe the antiquity of a medical practice is useful in assessing its validity, it is a compelling argument for some, so knowing the truth about this particular practice is of more than just academic interest.

Posted in Acupuncture | 9 Comments

A New Tool for Evaluating the Effects of Arthritis Treatments in Dogs

Posted on July 7, 2010 by skeptvet

There is an excellent article in the current issue of the Journal of the American Veterinary Medical Association which I wanted to draw attention to, both for its conttent and the design of the study.

Brown,D.C.; Boston,R.C.; Farrar,J.T. Use of an activity monitor to detect response to treatment in dogs with osteoarthritis. J.Am.Vet.Med.Assoc. 2010, 237, 1, 66-70.

A perennial problem in the evaluation of any therapy for arthritis in animals is the difficulty in assessing effect. Most studies use subjective evaluations by investigators or owners, which are subject to many kinds of bias and almost always show a benefit of every therapy for at least some of the multiple measures of function evaluated. A few studies use force plate analysis, where the dog walks over a device that measures how much weight they place on an arthritic limb. But this is a complex and often difficult measurement to take. The recent article describes a study using a small accelerometer to measure activity at home over a prolonged period. This is potentially a very useful tool in evaluating the efficacy of arthritis treatments in dogs.

The study was very well designed, and the authors clearly recognized the importance of controlling for investigator and owner bias even when using an objective measurement tool. The patients were randomized to treatment either with an agent already clearly established as effective (the NSAID Rimadyl) or an identical placebo, and both investigators and owners were blinded to the group assignment. Confounding factors were controlled for by selecting a study population newly diagnosed and not already treated, and by using statistical techniques to account for factors such as age, weight, and so on.

The results showed an expected increase in activity for the patients given Rimadyl (about 20% greater activity than before treatment) and no change from baseline for the placebo group. Interestingly, some of the dogs in the placebo group did show an increase in activity (20% of the dogs in this group had an increase of 10-30% in activity from the baseline period). As the authors explained, this sort of change likely represents the phenomenon of regression to the mean. For many chronic diseases, including arthritis, the symptoms wax and wane, getting worse and better alternately around an average, or mean, degree of severity. People tend to seek medical treatment, for themselves and their pets, when their symptoms are especially bad, and so the natural course of the disease tends to lead to an improvement in symptoms following an intervention regardless of whether the intervention is actually doing anything. Add to this the tendency for people to behave differently when involved in a medical study, usually exhibiting better health habits than they usually do, and it is routine for studies to show improvement with placebo therapies that aren’t actually doing anything. This is a significant contributor to the so-called “placebo effect.” It also explains why adequate controls are critical to showing real treatment effects, and why poorly controlled studies tend to find effects where they don’t really exist.

I am hopeful that the monitoring device discussed in this article will make it possible to more easily and inexpensively evaluate the effectiveness of the various purported osteoarthritis treatments currently in use as well as new treatments. I am less hopeful that such future studies will be as carefully designed and controlled as this one. Objective measures and all the statistics in the world don’t make experimental results real or useful unless human bias is adequately compensated for through techniques such as random allocation of subjects, blinding of investigators and owners, and placebo controls, or ideally a combination of active and placebo controls as well as no treatment at all. This study is a nice example of how such techniques should be used, as well as a demonstration of why they are needed.

Posted in Science-Based Veterinary Medicine | 3 Comments

Raw Pet Diet and “Natural” Pet Product Recalls

Posted on July 6, 2010 by skeptvet

One of the comments often made in defense of raw diets and challenging the safety  of conventional commercial pet foods is, “If those foods are so safe, why are they always being recalled?” The implication, of course, is that a recall is an indication a food is unsafe. The reality is that while this is sometimes true, many recalls are precautionary, and a real health threat is often not found when the recalled product is analyzed. This information, however, rarely gets the widespread coverage in the media or on the internet that the original recall did.

In any case, even if the suggestion that how many recalls one can remember for a given company or type of food was a reliable guide to safety, it is simply not true that alternative products or those marketed as “natural” and so on are not recalled. I don’t have any statistical analysis comparing the relative rate of recalls, precautionary or related to confirmed health threats, for all the pet food products out there, but it is easy to find examples of recalls involving raw diets, “natural” diets and supplements, and other products marketed as safer or healthier than conventional foods and treats. Dr. Susan Wynn, a veterinarian with specialty training in nutrition and an advocate of many veterinary CAM approaches, frequently reports such recalls on her blog, including several recently involving a raw diet for cats contaminated with Salmonella, and a long list of vitamins and supplements, also with possible Salmonella contamination.

These particular products may or may not present a danger to animal or human health, and certainly if there is a possibility that they do then voluntarily recalling them is the responsible thing for their manufacturers to do. But it’s important to remember that the claims of greater safety or health benefits from raw diets or supposedly “natural” food products are not substantiated by any evidence, and that these products, like any other, can have risks.

Posted in Nutrition | 5 Comments