Actually, stem cell therapies have been around for years, but only for very limited applications such as treating certain blood cancers. The debate surrounding the ethics of using embryonic stem cells, however, has highlighted the great potential of therapies based on stem cells.

Stem cells are undifferentiated cells that have the potential to turn into specific cell types. Embryonic stem cells are the most potent because they can theoretically turn into any cell type in the body. The hope of research into stem cells is that we can learn how to control the process of differentiation so that stem cells can be used therapeutically.

Potential applications that are already being researched include injection of stem cells into failing hearts—cells that will then turn into heart muscle cells and start beating along with the rest, strengthening the heart. While still experimental, this is likely to be an early application of this kind of use of stem cells. Similar experiments are underway using stem cells to repair damaged brains or spinal cords.

Stem cells might also be used not as replacement cells but as support cells. Genetically engineered stem cells can essentially become drug delivery systems or support cells that allow diseased cells to survive longer and function better.

But many hurdles remain, the biggest of which is keeping stem cells from becoming cancer cells. There is a reason our bodies are not already infused with stem cells that have unlimited regenerative ability (our bodies do have natural stem cells, but they are in specific numbers and locations). Stem cells share some characteristics with cancer cells, and injected stem cells are as likely to become cancers as replacements for diseased or injured cells.

Getting stem cells to do what we want them to, and getting them to survive long enough to do it, is also no trivial matter. Stem cells have tremendous potential, and they will likely be playing an increasing role in medical therapies over the next twenty years. But reality has yet to catch up with the hype.

The situation is ripe for exploitation. Stem cell clinics have been set up, mostly in poorly regulated countries such as China, India, and several countries in South America. They exist to lure in wealthy (by international standards) Westerners desperate for a cure (such as the parents of young blind children). Fees range from the tens of thousands to even hundreds of thousands of dollars, including the costs of travel. Most victims are not wealthy people who simply write a check but instead members of middle-class families who need to raise money for the treatments.

Once they have invested so much time, effort, and emotion and so many resources in the stem cell treatment—which often includes taking money from family, friends, and coworkers—these families have a huge investment in believing the treatment has worked, even when all objective evidence says otherwise. Often there is a temporary placebo effect from getting the treatment—or perhaps a temporary effect from the anesthesia or other aspects of the treatment—but no real improvement. But any fluctuation in symptoms is often interpreted as a sign the treatment has worked, which sometimes motivates the patients and their families to raise more money for more stem cell treatments.

The clinics themselves are not producing useful scientific data but are instead simply publicizing anecdotes of their success. There is often little transparency in what they are doing and no way of knowing what they are even injecting into their patients.

What little objective investigation we have into these stem cell clinic treatments reveals that patients are either unchanged or even harmed by the therapies. Ophthalmologist Shakesh Kaushal, of the University of Massachusetts, examined eight children treated with stem cells for blindness. “There didn’t seem to be any ostensible benefit from the stem-cell infusion,” he is quoted as saying in an NPR report, “in all of them, as far as we could tell” (Knox 2010).

Dobkin et al. (2006) reviewed the cases of seven patients who received stem cell injections for spinal cord injury. They conclude, “No clinically useful sensorimotor, disability, or autonomic improvements were found.” In other words, there was no benefit. There were, however, complications, including meningitis in five of the seven patients.

The media, for their part, mostly promote these fraudulent stem cell clinics. They often report stories of “miracle cures” in gushing terms, without the slightest amount of skepticism. These reports are little more than free advertisements for these clinics, driving more desperate patients through their doors.

Hope is a very positive emotion; it can keep us going in hard times, and it motivates all the hard work and investment it takes to develop high-tech treatments such as stem cell therapy. But there is a dark side to hope: false hope, promoted by premature uncritical hype. Unjustified hype also undermines legitimate therapies and scientific research as the public becomes disillusioned. While it is legitimate to discuss the great potential of stem cell therapies, such discussions must include the proper context. Stem cell therapies remain largely experimental, and there is no telling when or even if they will pan out.

The media need to take greater responsibility in relating these stories to the public. Medical professionals need to pay attention to what is happening, and they also need to get involved in properly informing the public. Governments need to pay close attention to how such clinics are regulated. And the public needs to approach claims of stem cell “miracles” with extreme skepticism and get advice from professionals before investing emotion and large amounts of resources into what is likely to be all hype and no hope.

References

Dobkin B.H., A. Curt, J. Guest. 2006. Cellular transplants in China: Observational study from the largest human experiment in chronic spinal cord injury. Neurorehabilitation and Neural Repair 20(1) (March): 5–13.

Knox, Richard. 2010. Offshore stem cell clinics sell hope, not science. NPR.org (July 26). Available online at www.npr.org/templates/story/story.php?storyId=128696529

Acupuncture is often referred to as an ancient Chinese practice, but in actuality it’s neither very ancient nor exclusively Chinese. The modern practice of acupuncture is only decades—not centuries or millennia, as is often claimed—old (Ramey 2010). It has antecedents in ancient times, but the practice of needling in Asia was not much different from the practice of bloodletting in the West (Novella 2010).

The National Center for Complementary and Alternative Medicine (NCCAM) has this to say about the definition of acupuncture:

The term “acupuncture” describes a family of procedures involving the stimulation of anatomical points on the body using a variety of techniques. The acupuncture technique that has been most often studied scientifically involves penetrating the skin with thin, solid, metallic needles that are manipulated by the hands or by electrical stimulation. (NCCAM 2011)

It appears the definition of acupuncture is not tied to any alleged mechanism of action. Some definitions mention Traditional Chinese Medicine (TCM) and either directly state or imply that acupuncture works by influencing the flow and balance of chi, or life energy. Such notions are little more than prescientific superstition, so modern proponents are often vague on mechanism or refer to highly speculative and unproven physiological mechanisms. Regardless of any potential mechanism, there are two features that seem to define acupuncture: the existence of specific acupuncture points at various locations on the body and the stimulation of these points by “a variety of techniques,” most commonly inserting thin needles through the skin.

So-called electroacupuncture is very problematic in terms of scientific specificity, because electrical stimulation through the skin has known physiological effects independent of the existence of acupuncture points. Scientific experiments are designed to control for as many variables as possible; only by isolating variables can we say which variable is having which effect. Electroacupuncture mixes variables, making it impossible to separate out the ones specific to acupuncture from the effects of electrical stimulation itself.

Needle insertion also has nonspecific physiological effects independent of any notion of acupuncture, but these are likely minimal, transient, and local. So for the purpose of experimentation, it is reasonable to define acupuncture as the insertion of thin needles into acupuncture points.

Clinical studies into the effectiveness of acupuncture have evolved over recent years, and there have actually been quite a few well-designed studies that adequately isolate these two variables (acupuncture points and needle insertion). For example, many studies compare verum acupuncture (true acupuncture in which needles are inserted into the alleged proper acupuncture points for the condition being treated) to sham acupuncture (in which needles are inserted into the “wrong” locations). These studies overwhelmingly show that needle location does not matter—verum acupuncture is no more effective than sham acupuncture (Moffet 2009; Ernst 2009).

Some trials also control for the variable of needle insertion, using placebo or simulated acupuncture in which opaque sheaths are used and a dull needle is pressed against the skin when the plunger is depressed, but there is no skin penetration. Alternatively, toothpicks have been used to simulate the sensation of acupuncture without going through the skin. Again, when this variable is isolated, it turns out that simulated acupuncture works as well as verum acupuncture. This is true of the largest and best trials of acupuncture for the most common uses, such as reducing back pain (Haake et al. 2007) and treating nausea (Enblom et al. 2011).

Therefore, if we define acupuncture as using needle insertion to stimulate acupuncture points, and the best scientific evidence shows that acupuncture points do not exist (it doesn’t matter where you stick the needles) and needle insertion has no effect (it doesn’t matter whether or not you stick the needles), then does acupuncture work? I think the only reasonable answer is no; there is no reality to acupuncture or the concepts upon which it is based.

If anything can be said to have a measurable effect in acupuncture trials it is the therapeutic ritual that surrounds acupuncture (but not the acupuncture itself). Even these effects are modest and nonspecific—they result from a subjective sense of well-being gained from the kind attention and relaxation that attends the acupuncture ritual.

We have known for decades that a good bedside manner, with some relaxation and encouragement, makes people feel better. This may create the illusion that whatever specific intervention accompanies these nonspecific effects is itself having some effect. That is the very point of scientific experiments: to isolate these variables. And when that is properly done, it becomes increasingly clear that acupuncture (the sticking of needles into alleged acupuncture points) does not work.

References

Enblom A., M. Lekander, M. Hammar, et al. 2011. Getting the grip on nonspecific treatment effects: Emesis in patients randomized to acupuncture or sham compared to patients receiving standard care. PLoS ONE 6(3): e14766. doi:10.1371/journal.pone.0014766.

Ernst, E. 2009. Acupuncture: What does the most reliable evidence tell us? Journal of Pain and Symptom Management. 37(4) (April): 709–14.

Haake, M., H.H. Müller, C. Schade-Brittinger, et al. 2007. German acupuncture trials (GERAC) for chronic low back pain: Randomized, multicenter, blinded, parallel-group trial with 3 groups. Archives of Internal Medicine. 167(17): 1892–98.

Moffet, H.H. 2009. Sham acupuncture may be as efficacious as true acupuncture: A systematic review of clinical trials. Journal of Alternative Complementary Medicine. 15(3) (March):213–16.

National Center for Complementary and Alternative Medicine (NCCAM). 2011. Acupuncture: An Introduction. Available online at http://nccam.nih.gov/health/acupuncture/introduction.htm.

Novella, S. 2010. Modern bloodletting (blog post). Neurologica (July 6). Available online at http://theness.com/neurologicablog/?p=2099.

Ramey, D. 2010. Acupuncture and history: The “ancient” therapy that’s been around for several decades (blog post). Science-Based Medicine (October 18). Available online at www.sciencebasedmedicine.org/?p=7660.

A Brief History of Homeopathy

Homeopathy was invented (it is not accurate to say it was discovered, which would imply it has some basis in reality) by Samuel Hahnemann in the late eighteenth century. Hahnemann developed his principles of homeopathy from anecdote and superstition without any chain of scientific research, evidence, or reasoning. It is therefore no surprise that more than two hundred years later, scientific progress has failed to validate any of Hahnemann’s ideas (House of Commons 2010).

Scientific knowledge builds on itself, and when someone discovers a fundamental property of nature, it leads to further discoveries and a deepened understanding. Homeopathy led to nothing. Hahnemann’s “law of similars” is the notion that “like cures like”—that a small dose of a substance will cure whatever symptoms it would cause in a high dose. This, however, is not based upon anything in biology or chemistry. It is often falsely compared to the body’s response to vaccines, but this is not an apt analogy.

Hahnemann’s “law of infinitessimals,” the notion that a substance becomes more potent when diluted, violates the law of mass action and everything we know about chemistry. Also, many homeopathic remedies are diluted past the point where even a single molecule of the original substance is likely to be left behind. Hahnemann believed that the water retained the magical “essence” of the substance, which makes homeopathy a vitalistic belief system.

Hahnemann’s ideas are sufficiently silly that even at the time, early in the history of science, they were ridiculed and dismissed. Homeopathy remains utterly nonsensical, but it is now much more sophisticated nonsense.

A recent fascination with unscientific health modalities has caused a resurgence of interest in homeopathy, leading to many clinical trials of the effectiveness of homeopathic products for specific ailments. After hundreds of clinical studies of homeopathy, systematic reviews reveal that homeopathic remedies are indistinguishable from placebos (another way of saying that they do not work) (Ernst 2010).

This is not even a scientific controversy—the evidence that homeopathy cannot work and does not work is overwhelming. Only ideology, wishful thinking, and scientific illiteracy keep it alive.

Water Memory

Modern defenders have desperately tried to justify homeopathy with scientific-sounding explanations, but they have failed miserably. One such attempt is the notion that water is capable of having memory—that it can physically remember the chemical properties of substances that have been diluted in it.

The notion of water memory was first raised by French homeopath Jacques Benveniste in 1988. He was not studying the water structure itself, just trying to demonstrate that water can retain the memory of antibodies or other substances diluted in it. His research, however, has been completely discredited due to the many flaws in Benveniste’s methods, his lab’s cherry-picking of data, his improper statistics, and his recounting data points that did not fit their desired results (Scrimgeour 2007).

Materials scientist Rustum Roy, who was enamored with spiritual healing, built upon Benveniste’s discredited research, claiming that water molecules are like bricks—they can be used to build structures that contain greater complexity and information than the bricks themselves. Specifically, water molecules can encode in their structure the chemical properties of what was diluted in them.

However, the evidence does not support this claim. What has been demonstrated is that water molecules form transient bonds with other water molecules, creating a larger ultrastructure—but these water structures are extremely short-lived. They are not permanent. In fact, research shows that water molecules very efficiently distribute energy from these bonds, making them extremely ephemeral. One such research paper concludes: “Our results highlight the efficiency of energy redistribution within the hydrogen-bonded network, and that liquid water essentially loses the memory of persistent correlations in its structure within 50 fs” (Cowan 2005). That’s fifty femtoseconds, or fifty quadrillionths (10^-15) of a second. Contrary to Roy’s claims, water does not hold memory. In fact it is characterized by being extremely efficient at not holding memory. Scientists can argue about whether or not water can display ultrastructure lingering for longer than femtoseconds under certain conditions—but they are arguing over incredibly small fractions of a second.

Recently Nobel Laureate Luc Montagnier has given a boost to the “water memory” hopes of homeopaths by publishing a series of experiments in which he claims that DNA highly diluted in water is able to generate radio signals (Montagnier 2009). There are numerous problems with these studies, however. Prime among them is that Montagnier’s study design is laughably sloppy (see Myers 2011). Montagnier used a crude signal detection device hooked up to a computer and generated worthless noise-ridden results. His studies proved nothing (and, not surprisingly, have not been replicated), but that has not stopped homeopaths from seizing upon his work to claim vindication.

So we are still left with no plausibility and no evidence that water can form ultrastructures for a biologically meaningful amount of time. It is amazing that Roy, Montagnier, and others so enthusiastically extrapolated from the claim that water can hold structures slightly longer than previously believed (itself probably bogus) to the notion that this can explain the biological effectiveness of homeopathy. Let’s take a close look at the nontrivial steps they glossed over.

If this kind of water “memory” is an explanation for homeopathy, then these structures would have to survive not only in a sample of water but through the physical mixing of that water with other water. In fact, they would have to transfer their structure, like a template, to surrounding water molecules. This would need to be reliably repeatable over many dilutions. Then these structures would have to survive transfer to a sugar pill (often homeopathic remedies are prepared by a drop of the water being placed onto a sugar pill).

These water structures would then have to be transferred to the sugar molecules because before long the water will evaporate. This pill will then sit on a shelf for days, months, or years before it is finally consumed by a gullible patient. The sugar pill will be broken down in the homeopathy proponent’s stomach, and the sugar molecules will then be digested, absorbed into the blood stream, and distributed through the blood to the tissues of the body.

Presumably, whatever molecules are retaining this alleged ultrastructure are sticking together throughout all of these processes and finding their way to the target organ in which they are able to have their chemical/biological effect.

Absurd does not even begin to cover the leaps of logic that are being committed here. In short, invoking water memory as an explanation for homeopathic effects just adds more layers of magical thinking to the notion of homeopathy; it wouldn’t offer a plausible explanation even if the theory of water memory was true, which it isn’t.

Some chemical bonds are strong enough to survive this process intact and make it through the body to the target tissue where they can bind to receptors or undergo their chemical reactions. Even most chemicals, however, cannot make it through this biological gauntlet with their chemical activity intact—which is why the bioavailability of many potential drugs is too low for them to be useful as oral agents. The chemicals are simply broken down by the digestive process. In other words, the ephemeral bonds of this alleged water memory—if this fiction of water memory even existed—would have a bioavailability of zero.

Conclusion

The notion that water has memory is nothing more than a restating of Hahnemann’s superstitious notion that substances can transfer their “vital essence” to other substances. Water memory is another fiction of homeopathy; it is not based upon any science and is implausible in the extreme.

References

Cowan M.L., B.D. Bruner, N. Huse, et al. 2005. Ultrafast memory loss and energy redistribution in the hydrogen bond network of liquid H2O. Nature 434 (March 10):199–202. doi:10.1038/nature03383.

Ernst, E. 2010. Homeopathy: What does the “best” evidence tell us? The Medical Journal of Australia 192(8) (April 19): 458–60.

House of Commons, Science, and Technology Committee. Evidence check 2: Homeopathy. Available online at www.publications.parliament.uk/pa/cm200910/cmselect/cmsctech/45/45.pdf.

Myers, P.Z. 2011. It almost makes me disbelieve that HIV causes AIDS. Pharyngula (January 24). Available online at http://scienceblogs.com/pharyngula/2011/01/it_almost_makes_me_disbelieve.php.

Montagnier L., J. Aissa, S. Ferris, et al. 2009. Electromagnetic signals are produced by aqueous nanostructures derived from bacterial DNA sequences. Interdisciplinary Sciences: Computational Life Sciences 1(2): 81–90.

Scrimgeour, H.J. 2007. Water memory tests all wet: A reassessment of the Benveniste experiments by a DVM. Association for Science and Reason (August 8). Available online at www.scienceandreason.ca/pseudoscience/alternativemedicine/water-memory-tests-all-wet/.

Magnetic charms, bracelets, insoles, and braces remain popular and are sold with claims that they improve athletic performance, relieve arthritis pain, increase energy, and pretty much treat whatever symptoms you might have. These products may seem modern and high-tech, but similar devices and claims have been around for centuries.

The notion that magnets can be used for healing has existed since humans discovered them. Several ancient cultures, such as those of Egypt, Greece, and China, discovered natural magnetic rocks, or lodestones. People had a hard time explaining the unusual properties of these rocks given the scientific knowledge of the time, so they came up with fanciful explanations like “minerals have souls too.” This was compatible with the general belief that everything has an “essence.”

It was also observed that this magnetic property can be transferred. Socrates wrote: “That stone not only attracts iron rings, but imparts to them a similar power of attracting other rings; and sometimes you may see many pieces of iron and rings suspended from one another to form quite a long chain; and all of them derive their power of suspension from the original stone” (quoted in Keithley 1999).

It then seemed natural that because living things have an energy and essence, and certain rocks contain an energy and essence, that such rocks could be used to heal illness-to transfer their energy to a living being. Even today, this idea has an emotional and even rational appeal. Who wouldn't want to be healed by the equivalent of McCoy's medical scanner, which non-invasively uses invisible and painless energy fields to return our tissues to health at the cellular level. When we fantasize about future medicine, that is what we imagine. It is no surprise, then, that through the centuries magnetic healing has been very popular-and its popularity has only increased with advancing scientific understanding of magnetism and the eventual discovery of electromagnetism.

The relationship between medical academia and popular marketing hasn't changed in hundreds of years either. In 1600, William Gilbert wrote De Magnete, in which he described detailed experiments with magnets and electricity and systematically disproved hundreds of popular health claims for such treatments. This established debunking of magnetic therapy continued into the seventeenth century with Thomas Browne (Macklis 1993). Considering how primitive scientific methods and medical knowledge were at this time, the claims of magnetic healers must have been especially fantastical and their treatments remarkably worthless.

But “The Man” was not able to keep magnetic healing down. In the eighteenth and nineteenth centuries, Franz Mesmer dramatically increased the popularity of magnetic healing with his “animal magnetism” theory. Mesmer thought that animal magnetism was a unique force of nature that flowed like a fluid through living things. He also thought he could manipulate it through a combination of hypnotism and laying-on of hands. After a high-profile debunking by a commission led by Benjamin Franklin, however, Mesmer's fame faded, and he died poor and forgotten. But his legacy survived-magnetic healing remains very popular to this day.

Today the relationship among magnets, popular health claims, and the medical/scientific community remains the same. The public is fascinated by the notion of healing with electricity, electromagnetic fields, and magnetic energy. The fact that many medical interventions are legitimately based upon electromagnetism increases this interest. People understand that we use magnetic resonance imaging (MRI) to peer into the body. Recent studies indicate the potential for transcranial magnetic stimulation as an effective treatment for migraines (Lipton and Pearlman 2010). We routinely measure electrical (and now even magnetic) brain waves to assess brain function.

Electromagnetism is the real energy of life, and therefore it is very plausible that all sorts of magnetic and electrical interventions will be useful for diagnostic and therapeutic purposes. But this potential also opens up a market for countless quack magnetic devices that exploit this appeal. You can buy what are essentially refrigerator magnets to strap to your elbow or knee or put in your shoe or under your pillow. These static magnetic fields have no demonstrable effect on blood flow or living tissue, and their fields are so shallow that they barely extend beyond the cloth in which they are encased, let alone to any significant tissue depth. The scientific evidence for their efficacy is negative (Pittler et al. 2007). Even more absurd are magnetic bracelets that are supposed to have a remote healing effect on the body. Their plausibility plummets even further.

It is eternally frustrating that scientific evidence and academic acceptance of medical claims seem to have no bearing on the marketing and popular appeal of those claims. This disconnect appears to be especially true of claims for magnetic devices and treatments-and it has survived for centuries.

References

Keithley, Joseph F. 1999. Measurements from the beginning through the Middle Ages. In The Story of Electrical and Magnetic Measurements: From 500 B.C. to the 1940s. New York: IEEE Press. Available online at http://media.wiley.com/product_data/excerpt/30/07803119/0780311930-2.pdf.

Lipton, Richard B., and Starr H. Pearlman. 2010. Transcranial magnetic simulation in the treatment of migraine. Neurotherapeutics 7(2) (April): 204–12.

Macklis, Roger M. 1993. Magnetic healing, quackery, and the debate about the health effects of electromagnetic fields. Annals of Internal Medicine 118(5) (March): 376–83.

Pittler, Max H., Elizabeth M. Brown, and Edzard Ernst. 2007. Static magnets for reducing pain: Systematic review and meta-analysis of randomized trials. Canadian Medical Association Journal 177(7) (September): 736–42.

A recent study looking into the effects of acupuncture on relieving back pain was widely reported in the media as finding that "acupuncture works, even fake acupuncture." Behind the headlines, the authors were more circumspect in the paper itself, concluding:

Although acupuncture was found effective for chronic low back pain, tailoring needling sites to each patient and penetration of the skin appear to be unimportant in eliciting therapeutic benefits. These findings raise questions about acupunctures purported mechanisms of action. It remains unclear whether acupuncture or our simulated method of acupuncture provide physiologically important stimulation or represent placebo or nonspecific effects. (Cherkin et al. 2009)

The authors compared acupuncture to placebo acupuncture (creating the sensation of acupuncture with toothpicks that do not penetrate the skin) and found no difference. When a drug is compared with a placebo and there is no difference in the response, the standard conclusion is that the drug has no effect--it does not work. But that logic is being turned on its head by what is being called "placebo medicine," in which the placebo effect is seen as a real, valuable, and desired outcome of patient treatment (Novella 2009).

Placebo effects (plural), however, are varied and complex. For the most part they are not a biological response to the expectation of benefit, which is what most people assume. Understanding placebo effects is critical to making sense of medical research and ever-expanding health claims within an increasingly unregulated market.

Operational Definition of Placebo

In the context of research, the "placebo effect" has a very specific operational definition: it is the treatment effect measured in the placebo arm of a clinical trial, which includes those subjects who have received a fake or inert treatment. If a trial is rigorously designed, placebo effects should include everything other than a physiological response to a biologically active treatment. Therefore, we can subtract placebo-effect findings from the treatment group, who will display treatment effects plus placebo effects, and we are left with a measurement of the treatment effect alone.

This simple but effective logic is the cornerstone of medical research. It is necessary because there are a variety of effects that can create the false impression that a treatment is working even when it isn't. It is a mistake to assume that the only relevant false impression is a "mind over matter" effect resulting from belief in the treatment. This is not the case.

Placebo Effects

Placebo effects fall into several categories: illusions of observation, bias, nonspecific effects, and physiological effects. Much of what is measured as a placebo effect is, in fact, simply an illusion of the process of observation. These illusory effects include regression to the mean, which is a statistical phenomenon that includes extreme symptoms becoming less extreme as a matter of course. For any variable symptom, periods of time when symptoms are at their worst are likely, by chance alone, to be followed by a return to more average symptoms.

Other artifacts include the biases of the researchers and the subjects. Researchers want their interventions to work and may therefore bias their assessments to be more positive. Subjects want to receive an effective treatment and to meet the expectations of the researcher. They want to justify their risk, expense (even if its just time), and their decision to receive a treatment or enter a trial. Conditioning, in which one associates a treatment ritual with feeling better, is another related placebo effect.

There are also a number of nonspecific effects, such as the well-documented observer effect (also called the Hawthorne effect), in which the very fact of being observed in a clinical trial results in a change in behavior and reporting (McCarney et al. 2007). People are more likely to be compliant with treatment, take better care of themselves, and get regular medical attention as part of a trial. Related to this is the cheerleader effect: for any functional assessment, people will tend to try harder if they are being encouraged, if they feel they should be doing better, or if they have hope that the treatment is working.

And finally there are real physiological effects resulting from the ritual of treatment. For example, treatment may involve relaxation or simply taking a break from your otherwise hectic daily routine. Believing one is being treated may reduce anxiety about the illness or symptoms, which in turn may reduce sympathetic activity, reduce blood pressure and strain on the heart, and reduce the levels of stress hormones. Hands-on treatments have the benefit of human contact, which improves mood and provides an overall feeling of well-being.

The perception of pain in particular is subject to these nonspecific effects, such as when an improved mood reduces the perception of pain. In addition, conditioning, expectation, and nonspecific benefits may actually cause the release of natural endorphins that reduce pain transmission (Benedetti 2007) or the release of dopamine in the reward centers of the brain (de la Fuente-Fernández and Stoessl 2004).

Breaking It Down

Given this more thorough understanding of placebo effects, it is not reasonable to assume that the measured placebo effect in a clinical trial is mostly or entirely a real "mind over matter" health benefit. Instead, the placebo effect may consist mostly or entirely of illusion and bias. One might ask, "Which kinds of effects are contributing to the measured placebo effect of specific treatments?" The answer is that it depends on what is being treated.

For example, a study of placebo effects in the treatment of irritable bowel syndrome (Kaptchuk et al. 2008) found a substantial placebo effect in place with the use of placebo acupuncture. The same study also found that the enhanced placebo group--members of which received placebo acupuncture with enhanced interaction between the therapist and the subject--reported added "warmth, attention, and confidence." After three weeks, the waiting-list group (those who received no treatment--not even placebo) had about a thirty-point drop on the symptom severity scale, with almost 30 percent of patients reporting adequate relief; the treatment group (those who received placebo acupuncture) had a forty-two-point drop, with 44 percent of patients reporting relief; the augmented group (those who received placebo acupuncture plus enhanced interaction with the therapist) reported a drop of over eighty points, with over 60 percent of patients reporting relief.

It's very interesting that the group that received no intervention, not even a placebo, still had a 30 percent response. This response is likely entirely due to observational artifacts (Hawthorne effect, etc.). The placebo intervention also led to an improved response--in this case, expectation and conditioning might be having an effect. The enhanced intervention group showed the strongest effect, likely representing an increase in the nonspecific benefits of a positive therapeutic relationship.

Hróbjartsson and Gøtzsche have been studying placebo effects for years. They recently reviewed clinical studies that contain a no-treatment arm as a way of measuring placebo effects. They conclude:

We did not find that placebo interventions have important clinical effects in general. However, in certain settings placebo interventions can influence patient-reported outcomes, especially pain and nausea, though it is difficult to distinguish patient-reported effects of placebo from biased reporting. The effect on pain varied, even among trials with low risk of bias, from negligible to clinically important. Variations in the effect of placebo were partly explained by variations in how trials were conducted and how patients were informed. (Hróbjartsson and Gøtzsche 2010)

Let's break this down a bit. First, Hróbjartsson and Gøtzsche found that when you look at any objective or clinically important outcome--the kinds of things that would indicate a real biological effect--there is no discernible placebo effect. That is, there is no "mind over matter" self-healing that can be attributed to the placebo effect.

What the authors found is also most compatible with the hypothesis that placebo effects, as measured in clinical trials, are mostly due to bias. Specifically, significant placebo effects were found only for subjectively reported symptoms. Further, the size of this effect varied widely among trials.

Conclusion

Increasingly, placebo effects are being used to justify the use of ineffective and even inert treatments, with the assumption that "the" placebo effect is a true healing effect. What the research indicates, however, is that there are many placebo effects, and they are mostly bias and illusion--not real effects. There are also nonspecific effects that are likely valuable, but these effects can mostly be categorized as stress reduction and improvement in mood through attention and encouragement. It should be remembered that any placebo effect worth having will also accompany a legitimate treatment that actually works. On close inspection, placebo effects are not a justification for substituting hocus-pocus for real medicine.

References

Benedetti, F. 2007. Placebo and endogenous mechanisms of analgesia. Handbook of Experimental Pharmacology 177: 393-413.

Cherkin, D.C., K.J. Sherman, A.L. Avins, J.H. Erro, L. Ichikawa, W.E. Barlow, K. Delaney, et al. 2009. A randomized trial comparing acupuncture, simulated acupuncture, and usual care for chronic low back pain. Archives of Internal Medicine 169(9): 858-66.

De la Fuente-Fernández, R., and A.J. Stoessl. 2004. The biochemical bases of the placebo effect. Science and Engineering Ethics 10(1): 143-50.

Hróbjartsson, A., and P.C. Gøtzsche. 2010. Placebo interventions for all clinical conditions. Cochrane Database Systematic Review (1): CD003974.

Kaptchuk, T.J., J.M. Kelley, L.A. Conboy, R.B. Davis, C.E. Kerr, E.E. Jacobson, I. Kirsch, et al. 2008. Components of placebo effect: Randomised controlled trial in patients with irritable bowel syndrome. British Medical Journal 336(7651): 999-1003.

McCarney, R., J. Warner, S. Iliffe, R. van Haselen, M. Griffin, and P. Fisher. 2007. The Hawthorne Effect: A randomised, controlled trial. BioMed Central Medical Research Methodology 7: 30.

Novella, S.P. 2009. The rise of placebo medicine. Available online at www.sciencebasedmedicine.org/?p=672.

Wakefield’s paper has already been thoroughly discredited, and subsequent studies have shown convincingly that there is a lack of association between MMR or vaccines in general and autism. For example, one of the key components of Wakefield’s theory is that autism is linked to gastrointestinal disorders in some children, potentially allowing the measles virus from the vaccine to enter the bloodstream and wreak havoc. A replication of Wakefield’s experiment by Mady Hornig was published last September in PLoS ONE (Hornig 2008). Hornig found no correlation between MMR and autism and also did not find the measles virus in the guts of children with autism and GI complaints, directly contradicting Wakefield.

Far larger than the scientific controversy stirred up by Wakefield, which has largely been settled, is the storm of ethical concerns regarding his scientific behavior. In 2004, ten of Wakefield’s co-authors withdrew their names from the original publication, and The Lancet’s editors published a retraction, citing undisclosed conflicts of interest by Wakefield (Lancet 2004). Specifically, Wakefield did not disclose a large consulting fee he received from attorneys representing clients suing over claims that their children’s autism was caused by MMR. In fact, eleven of the twelve children in Wakefield’s study were part of the litigation. Further, nine months prior to publishing the study, Wakefield applied for a patent for a new MMR vaccine that he claimed was safer. He therefore stood to make phenomenal profits from scares over the current vaccine’s safety (Deer 2008).

Investigative journalist Brian Deer has been putting the pieces of the Wakefield puzzle together for several years now. His investigations recently uncovered evidence that Wakefield may also have faked his original data. He writes: “Our investigation, confirmed by evidence presented to the General Medical Council (GMC), reveals that: In most of the twelve cases, the children’s ailments as described in The Lancet were different from their hospital and GP records. Although the research paper claimed that problems came on within days of the jab, in only one case did medical records suggest this was true, and in many of the cases medical concerns had been raised before the children were vaccinated. Hospital pathologists, looking for inflammatory bowel disease, reported in the majority of cases that the gut was normal. This was then reviewed and The Lancet paper showed them as abnormal” (Deer 2009).

Andrew Wakefield remains under investigation by the U.K.’s General Medical Council for ethics violations. He remains unrepentant about his claims and has since moved to America, where he runs the Thoughtful House autism center in Austin, Texas.

References

• Deer, B. 2009. MMR doctor Andrew Wakefield fixed data on autism. Times Online, February 8. Available online.
• —.2008. The Wakefield Factor. Available online at http://briandeer.com/wakefield-deer.htm.
• Hornig, M, T. Briese, T. Buie, M.L. Bauman, G. Lauwers, U. Siemetzki, K. Hummel, P.A. Rota, W.J. Bellini, J.J. O’Leary, O. Sheils, E. Alden, L. Pickering, W.I. Lipkin. 2008. Lack of association between measles virus vaccine and autism with enteropathy: A case-control study. PLoS ONE, September. Available online.
• Editors. 2004. A statement by the editors of The Lancet. The Lancet 363 (9411).
• Wakefield, A.J., S.H. Murch, A. Anthony, J. Linnell, D.M. Casson, M. Malik, M. Berelowitz, A.P. Dhillon, M.A. Thomson, P. Harvey, A. Valentine, S.E. Davies, and J.A. Walker-Smith. 1998. Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. The Lancet 351 (9103):637–41.

Michelle Cedillo has autism, which her parents believe is the result of her childhood vaccines. In June 2007 they had the opportunity, along with eight other families, to make their case to the Autism Omnibus—a U.S. Court of Federal Claims that was presided over by three “special masters” appointed for the purpose. These nine cases are the first test cases that will likely determine the fate of 4,800 other claims made over the past eight years for compensation for injuries allegedly due to childhood vaccines.

Vaccines are one of the most successful programs in modern health care, reducing, and in some cases even eliminating, serious infectious diseases. Public support for the vaccination program remains strong, especially in the United States where vaccination rates are currently at an all-time high of >95 percent (CDC 2004). Yet, despite a long history of safety and effectiveness, vaccines have always had their critics: some parents and a tiny fringe of doctors question whether vaccinating children is worth what they perceive as the risks. In recent years, the anti-vaccination movement, largely based on poor science and fear-mongering, has become more vocal and even hostile (Hughes 2007).

Of course, vaccines are not without risk (no medical intervention is), although the benefits far outweigh those risks. Because vaccines are somewhat compulsory in the United States—although opting out is increasingly easy—a National Vaccine Injury Compensation Program was established to streamline the process for compensation for those who are injured due to vaccines (USDOJ 2007). It is this program to which the Cedillo and 4,800 other families are applying for compensation.

In the last decade, the anti-vaccine movement, which includes those who blame the MMR (mumps-measles-rubella) vaccine for autism, has largely merged with those who warn that mercury toxicity is the cause of many of the ills that plague mankind. The two groups have come together over the issue of thimerosal, a mercury-based preservative in some vaccines. They believe that it was the use of thimerosal in childhood vaccines that led to the apparent autism epidemic beginning in the 1990s.

Autism is a complex neurological disorder that typically manifests in the first few years of life and primarily involves a deficiency of typical social skills and behavior. In the 1990’s, the number of autism diagnoses significantly increased, from between one and three to about fifteen cases per ten thousand, although the true incidence is probably between thirty and sixty per ten thousand (Rutter 2005). During this same period, the number of vaccines given in the routine childhood schedule also increased. This led some to assume, or at least speculate, causation from correlation—perhaps the vaccines or something in them created this “epidemic” of autism.

We can now say, from multiple independent lines of evidence, that vaccines do not cause autism. For one thing, the autism “epidemic” probably does not represent a true increase in the disorder, but rather an artifact of expanding the diagnosis (now referred to as autism spectrum disorder, ASD) and increased surveillance (Taylor 2006).

In 1998, researcher Andrew Wakefield and some of his colleagues published a study in the prestigious English medical journal Lancet that claimed to show a connection between the MMR vaccine and autism (Wakefield 1998). Wakefield’s theory was that the MMR vaccine, which contains a live virus, can cause in susceptible children a chronic measles infection. This in turn leads to gastrointestinal disturbances, including what he calls a “leaky gut” syndrome, which then allows for certain toxins and chemicals, like those from bread and dairy that are normally broken down by the gut, to enter the bloodstream where they can access and damage the developing brain.

Although the study was small and the evidence was considered preliminary, this article sparked a firestorm. As a result of the study and the media coverage that followed (and continues to this day), MMR compliance in Great Britain plummeted, resulting in a surge of preventable disease (Friederichs 2006).

Subsequent to the seminal article in the Lancet, many follow-up studies were performed testing the autism-MMR vaccine correlation. As the follow-up studies began to be published, however, it became increasingly clear that there was no link between MMR and autism. For example, a study in the British Medical Journal found that autism rates continued to climb in areas where MMR vaccination rates were not increasing (Taylor 1999). Another study found no association with MMR and autism or GI (gastrointestinal) disorders (Taylor 2002). Other studies showed no difference in the diagnosis rate of autism either before or after the MMR vaccine was administered (Honda 2005), or between vaccinated and unvaccinated children (Madsen 2002). Most recently, a study found that there was no decrease in autism rates following removal of the MMR vaccine in Japan (Honda 2005).

In 2001, the Institute of Medicine (IOM) reviewed all of the MMR-autism data available to date and concluded that there was no association and essentially closed the case (IOM 2001)—a conclusion confirmed by still later studies, such as the Honda study in Japan cited above.

If Wakefield had simply been wrong in his preliminary findings, he would be innocent of any wrongdoing—scientists are not faulted if their early findings are not later vindicated. However, in May 2004, ten of Wakefield’s co-authors on his original paper withdrew their support for its conclusions. The editors of Lancet also announced that they withdrew their endorsement of the paper and cited as part of the reason an undisclosed potential conflict of interest for Wakefield, namely that at the time of its publication he was conducting research for a group of parents of autistic children seeking to sue for damages from MMR vaccine producers (Lancet 2004).

It gets worse. Investigative reporter Brian Deer has uncovered greater depths to Wakefield’s apparent malfeasance. Wakefield had applied for patents for an MMR vaccine substitute and treatments for his alleged MMR vaccine-induced gut disorder (Deer 2007). So, not only was he allegedly paid by lawyers to cast doubt on the MMR vaccine, but he stood to personally gain from the outcome of his research.

Andrew Wakefield. (Credit: Tom Miller) [Photo via Newscom]

Further, during the Cedillo case testimony, Stephen Bustin, a world expert in the polymerase chain reaction (PCR), testified that the lab Wakefield used to obtain the results for his original paper was contaminated with measles virus RNA. It was therefore likely, Bustin implied, that the PCR used by Wakefield was detecting this contamination and not evidence for measles infection in the guts of children with autism who had been vaccinated, as Wakefield claimed. And finally, Nicholas Chadwick testified that the measles RNA Wakefield found matched the laboratory contamination and did not match either any naturally occurring strain or the strain used in the MMR vaccine—a fact of which he had informed Wakefield (USCFC 2007).

All of this, plus other allegations still coming out, has caused Britain’s General Medical Council to call Wakefield before its “Fitness to Practise” panel for review of his alleged professional misconduct (GMC 2007).

Believers in the MMR-autism hypothesis dismiss the findings of the larger and more powerful epidemiological studies that contradict a link. Instead, they have turned Andrew Wakefield into a martyr, dismissing the evidence of his wrongdoing as a conspiracy against him designed to hide the true cause of autism from the public. Wakefield is unrepentant and maintains his innocence (Gorski 2007).

With the MMR-autism hypothesis scientifically dead, attention soon shifted to thimerosal, a mercury-based preservative found in some childhood vaccines (although not the MMR vaccine). There is little doubt, and no controversy, that mercury, the major component of thimerosal, is a powerful neurotoxin, or poison to the brain. However, toxicity is always a matter of dose. Everything becomes toxic in a high enough dose; even too much water or vitamin C can kill you. So the real question is whether the amount of mercury given to children in vaccines containing thimerosal was enough to cause neurological damage.

Author of the book Evidence of Harm: Mercury in Vaccines and the Autism Epidemic David Kirby (center) speaks as president Harvey Fineberg (left) of the Institute of Medicine listens during an interview by moderator Tim Russert (right) on NBC’s Meet the Press August 7, 2005, at the NBC studios in Washington, D.C. Fineberg and Kirby talked about the rising number of autism diagnoses among children and the controversial charges of a government conspiracy to allow mercury exposures from childhood vaccines to more than double between 1988 and 1992. The Institute of Medicine reviewed all MMR-autism data and concluded that there was no association. (Photo by Alex Wong/Getty Images for Meet the Press) [Photo via Newscom]

Proponents of the mercury hypothesis argue that the ethylmercury found in thimerosal was given in doses exceeding Environmental Protection Agency limits. This load of mercury should be considered with prenatal vaccine loads possibly given to mothers, and to other environmental sources of mercury, such as seafood. Furthermore, underweight or premature infants received a higher dose by weight than larger children. Some children, they argue, may have a specific inability to metabolize mercury, and perhaps these are the children who become autistic.

Fear over thimerosal and autism was given a huge boost by journalist David Kirby with his book Evidence of Harm (Kirby 2005). Kirby tells the clichéd tale of courageous families searching for help for their sick children and facing a blind medical establishment and a federal government rife with corruption from corporate dollars. Kirby echoes the core claim that as the childhood vaccine schedule increased in the 1990s, leading to an increased cumulative dose of thimerosal, autism diagnoses skyrocketed.

In the end, Evidence of Harm is an example of terrible reporting that grossly misrepresents the science and the relevant institutions. As bad as Kirby’s position was in 2005, in the last two years the evidence has been piling up that thimerosal does not cause autism. Rather than adjusting his claims to the evidence, Kirby has held fast to his claims, which has made him a hero alongside Wakefield of the mercury-autism-connection crowd as he has squandered his credibility.

There have now been a number of epidemiological and ecological studies that have all shown no correlation between thimerosal and autism (Parker 2004 and Doja 2006). I have already mentioned that the current consensus holds that there is no real autism epidemic, just an artifact of how the diagnosis is made. If there’s no epidemic, there’s no reason to look for a correlation between thimerosal and autism. This has been backed up by The Institute of Medicine, which has also reviewed all the available evidence (both epidemiological and toxicological) and concluded that the evidence does not support the conclusion that thimerosal causes autism (IOM 2004).

Especially damning for the thimerosal hypothesis are the recent studies that clearly demonstrate that early detection of autism is possible long before the diagnosis is officially made. Part of the belief that vaccines may cause autism is driven by the anecdotal observation by many parents that their children were normal until after they were vaccinated—autism is typically diagnosed around age two or three. However, more careful observations indicate that signs of autism are present much earlier, even before twelve months of age, before exposure to thimerosal (Mitchell 2006). In fact, autism expert Eric Fombonne testified in the Autism Omnibus hearings that Michelle Cedillo displayed early signs of autism clearly visibly on family video taken prior to her receiving the MMR vaccine (USCFC 2007).

Meanwhile, evidence is accumulating that autism is largely a genetic disorder (Szatmari 2007). This by itself does not rule out an environmental factor, but it is telling that genetic research in autism has proven so fruitful.

Mercury alarmists, in the face of this negative evidence, have been looking for rationalizations. Some have argued that the thimerosal in prenatal vaccines may be to blame, but recent evidence has shown a negative correlation there as well (Miles 2007).

What we have are the makings of a solid scientific consensus. Multiple independent lines of evidence all point in the same direction: vaccines in general, and thimerosal in particular, do not cause autism, which rather likely has its roots in genetics. Furthermore, true autism rates are probably static and not rising.

A demonstrator carries a sign protesting the use of mercury in vaccines past the U.S. Capitol in Washington July 20, 2005. Some three hundred people marched demanding that mercury not be used in vaccines anymore amid concern that it is the cause of autism and other neurological diseases in children. However, numerous studies show no correlation between Thimerosol and autism. (Nicholas Kamm/AFP/Getty Images) [Photo via Newscom]

The only researchers who are publishing data that contradicts this consensus are the father-and-son team of Mark and David Geier. They have looked at the same data and concluded that thimerosal does correlate with autism. However, the hammer of peer-review has come down on their methods and declared them fatally flawed, thus rendering their conclusions invalid or uninterpretable (Parker 2004). Also, like Wakefield, their reputations are far from clean. They have made something of a career out of testifying for lawyers and families claiming that vaccines caused their child’s autism, even though the Geiers’ testimony is often excluded on the basis that they lack the proper expertise (Goldacre 2007). The Geiers were not even called as experts in the Autism Omnibus hearings.

The Geiers are now undertaking an ethically suspect study in which they are administering chelation therapy to children with autism in conjunction with powerful hormonal therapy allegedly designed to reduce testosterone levels. Chelation therapy removes mercury, and so it is dependent upon the mercury hypothesis, which is all but disproved. Moreover, there is no clinical evidence for the efficacy of chelation therapy. The treatment is far from benign and is even associated with occasional deaths (Brown 2006).

With the scientific evidence so solidly against the mercury hypothesis of autism, proponents maintain their belief largely through the generous application of conspiracy thinking. The conspiracy claim has been made the loudest by Robert F. Kennedy Jr. in two conspiracy-mongering articles: Deadly Immunity published on Salon.com in 2005 (Kennedy 2005), and more recently Attack on Mothers (Kennedy 2007). In these articles, RFK Jr. completely misrepresents and selectively quotes the scientific evidence, dismisses inconvenient evidence as fraudulent, accuses the government, doctors, and the pharmaceutical industry of conspiring to neurologically damage America’s children, and accuses scientists who are skeptical of the mercury claims of attacking the mothers of children with autism.

Despite the lack of evidence for any safety concern, the FDA decided to remove all thimerosal from childhood vaccines, and by 2002 no new childhood vaccines with thimerosal were being sold in the U.S. This was not an admission of prior error, as some mercury proponents claimed; instead, the FDA was playing it safe by minimizing human exposure to mercury wherever possible. The move was also likely calculated to maintain public confidence in vaccines.

This created the opportunity to have the ultimate test of the thimerosal autism hypothesis. If rising thimerosal doses in the 1990s led to increasing rates of autism diagnosis, then the removal of thimerosal should be followed within a few years by a similar drop in new autism diagnoses. If, on the other hand, thimerosal did not cause autism, then the incidence of new diagnoses should continue to increase and eventually level off at or near the true rate of incidence. In 2005, I personally interviewed David Kirby on the topic, and we both agreed that this would be a fair test of our respective positions. Also, in an e-mail to science blogger Citizen Cain, Kirby wrote, “If the total number of 3-5 year olds in the California DDS [Department of Developmental Services] system has not declined by 2007, that would deal a severe blow to the autism-thimerosal hypothesis” (Cain 2005).

Well, five years after the removal of thimerosal, autism diagnosis rates have continued to increase (IDIC 2007). That is the final nail in the coffin in the thimerosal-vaccine-autism hypothesis. The believers, however, are in full rationalization mode. David Kirby and others have charged that although no new vaccines with thimerosal were sold after 2001, there was no recall, so pediatricians may have had a stockpile of thimerosal-laden vaccines—even though a published inspection of 447 pediatric clinics and offices found only 1.9 percent of relevant vaccines still had thimerosal by February 2002, a tiny fraction that was either exchanged, used, or expired soon after (CDCP/ACIP 2002).

Those who argue for the link have put forth increasingly desperate notions. Kirby has argued that mercury from cremations was increasing environmental mercury toxicity and offsetting the decrease in mercury from thimerosal. The Geiers simply reinterpreted the data using bad statistics to create the illusion of a downward trend where none exists (Geier 2006). Robert Kennedy Jr. dodges the issue altogether by asking for more studies, despite the fact that the evidence he asks for already exists. He just doesn’t like the answer. Kennedy and others also point to dubious evidence, such as the myth that the Amish do not vaccinate and do not get autism. Both of these claims are not true, and the data RFK Jr. refers to is nothing more than a very unscientific phone survey (Leitch 2007).

The Autism Omnibus hearings have concluded, and while we await the decision due early next year, I am optimistic that science and reason will win the day. Just as shown in the 2005 Dover trial of intelligent design where the full body of scientific evidence was given a thorough airing in court and subjected to rules of evidence and the critical eyes of experienced judges, science tends to win out over nonsense. By all accounts, the lawyers for those claiming that vaccines caused their children’s autism put on pathetic performances with transparently shoddy science, while the other side marshaled genuine experts and put forth an impressive case.

But the stakes are high, and not just for the 4,800 families. If the petitioners win these test cases despite the evidence, it will open the floodgates for the rest of the 4,800 petitioners. This will likely bankrupt the Vaccine Injury Compensation Program and will also risk our vaccine infrastructure. Pharmaceutical companies will be reluctant to subject themselves to the liability of selling vaccines if even the truth cannot protect them from lawsuits.

Thimerosal still exists as a necessary preservative in multi-shot vaccines outside the United States, especially in poor third-world countries that cannot afford stockpiles of single-shot vaccines. Anti-thimerosal hysteria therefore also threatens the health of children in poor countries.

And of course a victory for the anti-vaccination activists would undermine public confidence in what is arguably the single most effective public health measure devised by modern science. This decrease in confidence will lead, as it has before, to declining compliance and an increase in infectious disease.

The forces of irrationality are arrayed on this issue. There are conspiracy theorists, well-meaning but misguided citizen groups who are becoming increasingly desperate and hostile, irresponsible journalists, and ethically compromised or incompetent scientists. The science itself is complex, making it difficult for the average person to sift through all the misdirection and misinformation. Standing against all this is simple respect for scientific integrity and the dedication to follow the evidence wherever it leads.

Right now the evidence leads to the firm conclusion that vaccines do not cause autism. Yet, if history is any guide, the myth that they do cause autism will likely endure even in the face of increasing contradictory evidence.

References

• Brown, M.J., T. Willis, B. Omalu, and R. Leiker. 2006. Deaths resulting from hypocalcemia after administration of edetate disodium: 2003–2005. Pediatrics. 118(2):e534–36.
• Centers for Disease Control. 2004. MMWR Weekly, November 12. 53(44):1041–1044. Available at www.cdc.gov/mmwr/preview/mmwrhtml/mm5344a4.htm.
• Centers for Disease Control and Prevention Advisory Committee on Immunization. 2002. Practice Records of the meeting held on February 20–21, 2002, Atlanta Marriott North Central Hotel. Available at www.kevinleitch.co.uk/grabit/acip-min-feb.pdf.
• Citizen Cain. 2005. Slouching Toward Truth—Autism and Mercury, November 30. Available at http://citizencain.blogspot.com/2005/11/slouching-toward-truth-autism-and_30.html.
• Deer, B. 2007. Andrew Wakefield & the MMR scare: part 2. Available at http://briandeer.com/wakefield-deer.htm.
• Doja, A., and W. Roberts. 2006. Immunizations and autism: a review of the literature. Canadian Journal of Neurological Sciences 33(4):341–46.
• Friederichs, V., J.C. Cameron, and C. Robertson. 2006. Impact of adverse publicity on MMR vaccine uptake: a population based analysis of vaccine uptake records for one million children, born 1987–2004. Archives of Diseases of Children 200691(6):465–68. Epub 2006 April 25.
• Geier, D.A., and M.R. Geier. 2006. An assessment of downward trends in neurodevelopmental disorders in the United States following removal of thimerosal from childhood vaccines. Medical Science Monitor 12(6):CR231–9. Epub 2006 May 29.
• General Medical Council. 2007. July 16. Available at www.gmcpressoffice.org.uk/apps/news/events/index.php?month=7&year=2007&submit=Submit.
• Goldacre B. 2007. Opinions from the medical fringe should come with a health warning. The Guardian, Saturday, February 24. Available at www.guardian.co.uk/science/2007/feb/24/badscience.uknews.
• Gorski, D. 2007. Andrew Wakefield: The Galileo gambit writ large in The Observer. Respectful Insolence, July 9, 2007. Available at http://scienceblogs.com/insolence/2007/07/andrew_wakefield_the_galileo_gambit_writ.php.
• Honda, H., Y. Shimizu, and M. Rutter. 2005. No effect of MMR withdrawal on the incidence of autism: a total population study. Journal of Child Psychology and Psychiatry 46(6):572–79.
• Hughes, V. 2007. Mercury Rising. Nature Medicine 13(8):896–7. Epub 2007 August 31.
• Infectious Diseases and Immunization Committee, Canadian Paediatric Society (CPS). 2007. Autistic spectrum disorder: No causal relationship with vaccines. Paediatrics & Child Health 12(5): 393–95. Available at www.cps.ca/english/statements/ID/pidnote_jun07.htm.
• Institute of Medicine. 2001. Immunization Safety Review: Measles-Mumps-Rubella Vaccine and Autism. April 23. Available at www.iom.edu/CMS/3793/4705/4715.aspx.
• Institute of Medicine. 2004. Immunization Safety Review: Vaccines and Autism. May 17. Available at www.iom.edu/CMS/3793/4705/20155.aspx.
• Kennedy, R.F. 2005. Deadly immunity. June 16. Salon.com. Available at http://dir.salon.com/story/news/feature/2005/06/16/thimerosal/index3.html?pn=1.
• ———. 2007. Attack on mothers. June 19. The Huffington Post. Available at www.huffingtonpost.com/robert-f-kennedy-jr/attack-on-mothers_b_52894.html.
• Kirby, David. 2005. Evidence of Harm: Mercury in Vaccines and the Autism Epidemic: A Medical Controversy. New York: St. Martin’s Press.
• Lancet Editors, 2004. Lancet 363(9411).
• Leitch K. 2007. Autism amongst the Amish. Left Brain/Right Brain. 22. Available at www.kevinleitch.co.uk/wp/?p=5353.
• Madsen, K.M., A. Hviid, M. Vestergaard, D. Schendel, J. Wohlfahrt, P. Thorsen, J. Olsen, and M. Melbye. 2002. A population-based study of measles, mumps, and rubella vaccination and autism. New England Journal of Medicine 347(19):1477–1482.
• Miles, J.H., and T.N. Takahashi. 2007. Lack of association between Rh status, Rh immune globulin in pregnancy and autism. American Journal of Medical Genetics, Part A1. 143(13):1397–407.
• Mitchell, S., J. Brian, L. Zwaigenbaum, W. Roberts, P. Szatmari, I. Smith, and S. Bryson. 2006. Early language and communication development of infants later diagnosed with autism spectrum disorder. Journal of Developmental and Behavioral Pediatrics 27(2 Suppl):S69–78.
• Parker, S.K., B. Schwartz, J. Todd, and L.K. Pickering. 2004. Thimerosal-containing vaccines and autistic spectrum disorder: a critical review of published original data. Pediatrics 114(3):793–804.
• Rutter, M. 2005. Incidence of autism spectrum disorders: changes over time and their meaning. Acta Paediatrica 94(1):2–15.
• Szatmari, P., et. al. 2007. Mapping autism risk loci using genetic linkage and chromosomal rearrangements. Nature Genetics 39, 319–28.
• Taylor, B. 2006. Vaccines and the changing epidemiology of autism. Child Care, Health, and Development 32(5):511–19.
• Taylor, B., E. Miller, C.P. Farrington, M.C. Petropoulos, I. Favot-Mayaud, J. Li, and P.A. Waight. 1999. Autism and measles, mumps, and rubella vaccine: no epidemiological evidence for a causal association. Lancet 12;353(9169):2026–2029.
• Taylor, B., E. Miller, R. Lingam, N. Andrews, A. Simmons, and J. Stowe. 2002. Measles, mumps, and rubella vaccination and bowel problems or developmental regression in children with autism: population study. British Medical Journal 16; 324(7334):393–96.
• United States Court of Federal Claims. 2007. Cedillo v. Secretary of Health and Human Services, Transcript of Day 6. June 18, 2007. Available at ftp://autism.uscfc.uscourts.gov/autism/transcripts/day06.pdf.
• United States Court of Federal Claims, 2007. Cedillo v. Secretary of Health and Human Services, Transcript of Day 8. June 20, 2007. Available at ftp://autism.uscfc.uscourts.gov/autism/transcripts/day08.pdf.
• USDOJ, About the National Vaccine Injury Compensation Program. Available at www.usdoj.gov/civil/torts/const/vicp/about.htm.
• Wakefield, A.J., S.H. Murch, A. Anthony, J. Linnell, D.M. Casson, M. Malik, M. Berelowitz, A.P. Dhillon, M.A. Thomson, P. Harvey, A. Valentine, S.E. Davies, and J.A. Walker-Smith. 1998. Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. Lancet 351(9103):637–41.

The term skepticism has a number of meanings, which can sometimes lead to misunderstandings between those who use the word one way and those who interpret it another. Of particular interest, and frequently the focus of such misunderstandings, is the stance of skeptics and organized skepticism toward religion and faith. This article will address that issue by defining the term skepticism as it is used by most local skeptical organizations-at least in the view of the authors.

Let us first recall that this magazine is published by the Committee for the Scientific Investigation of Claims of the Paranormal. The word scientific is emphasized here with good reason-it is not the Committee for Philosophical Discussions or the Committee for Religious Debates. The very name of this organization dedicates itself to scientific investigations. The local groups generally echo this viewpoint-often by stating directly that they are dedicated to the application of the scientific method to paranormal and fringe-science phenomena. We will use the term scientific skeptics to denote those who share this viewpoint.

There are others who believe that religion is a fair topic for skeptical analysis; we will use the term rationalists to denote these, because proponents of this view often promote the idea that atheism, or at least non-theism, and skepticism are both part of the same rationalist philosophy. Under this philosophy, a rationalist takes a materialistic, scientific approach to the world and renounces all superstition. There is no distinction between believing in leprechauns, alien abductions, ESP, reincarnation, or the existence of a god-each equally lacks objective evidence.

From this perspective, separating out the latter two beliefs and labeling them as religion-thereby exempting them from critical analysis-is intellectually dishonest. Rationalists often conclude that such behavior is motivated by a desire to avoid those superstitions that are most prominent in our particular culture out of fear of being excessively controversial. For one who promotes rationalism, the most widespread and sacredly guarded superstitions are the most important ones to oppose, for they have the greatest influence and can therefore do the most harm.

Scientific skepticism, however, defines skepticism more around the principles of scientific investigation than around the broader concept of rationalism. According to this view, there is a meaningful distinction between different kinds of beliefs. Specifically, scientific skepticism addresses testable claims, focusing on those that are controversial because they deal with the paranormal or the fringes of science, areas traditionally lacking adequate scientific rigor.

Untestable Claims

Claims that are not testable are simply outside the realm of science. A good example of this is the old creationist argument that God created the world to appear exactly as if it had evolved naturally over four billion years, fossils and all. This claim is certainly consistent with the evidence, but it makes no predictions that can be tested against future observations. In fact, it is designed to eliminate any observable distinction between an evolved and a created world. It is therefore important to identify such claims as untestable and therefore nonscientific because such claims are worthless to the advancement of knowledge. They cannot, by definition, be eliminated through evidence; therefore they must be banished to a realm outside of science.

What can a scientific skeptics’ group say about such claims? Only that they are outside the realm of science, and that science can have only an agnostic view toward untestable hypotheses. A rationalist may argue that maintaining an arbitrary opinion about an untestable hypothesis is irrational-and he may be right. But this is a philosophical argument, not a scientific one. If an individual makes a personal choice to maintain a belief regarding an untestable hypothesis with no claims to evidence in support of that belief, then there is no scientific basis on which to challenge the belief. It is best labeled faith, which distinguishes it from a belief based on evidence.

The most obvious such belief is a person’s answer to the question, “Does God exist?” There is simply no scientific way to know the answer to this. Certainly many people think they know the answer, and that is satisfying to them. Some have written entire books on why the universe does not need to have a god, but that does not prove that a god is nonexistent. Indeed, any omnipotent being worth his salt should be able to create a universe that doesn't have obvious inconsistencies in it.

So that question comes down purely to faith. Either you believe in a god, or you don't. Science cannot answer that question.

Faith and Science

The real distinction made by scientific skepticism is not between religion and nonreligion, but between faith and science. A faith-based belief may be religious, New Age, paranormal, or even social. Testable religious claims, such as those of creationists, faith healers, and miracle men, however, are amenable to scientific skepticism. Therefore, anyone who claims to have scientific evidence for the existence of God has stepped into the scientific arena and is now open to skeptical criticism. These claims are part of the heart and soul (if you'll excuse the metaphor) of CSICOP and the local skeptics groups. But an individual professing a personal faith in God, who does not try to justify this faith with evidence, is immune to scientific arguments.

One criticism that has been leveled at this view is that we are merely trying to avoid offending people. Certainly, that is one part of it-but not for the reason that charge is leveled. Some rationalists have often assumed that all skeptics must be, like them, nontheists. As we've said, they often do not understand how one can be a skeptic and at the same time hold religious beliefs. Experiences in the local groups, however, show that one can indeed be a skeptic and still be religious. REALL, the Rational Examination Association of Lincoln Land, has among its Patron members a retired reverend and a rabbinical school applicant (along with several outspoken atheists). Other local group leaders have similar examples; one even advertises its meetings in a church newsletter! So it certainly would offend those people to assume all skeptics to be nontheists. They are working to advance the same cause-the same way of thinking-as all the other skeptics are, so why should we push them away?

An argument often advanced against this position is that we do not accept others who hold beliefs contrary to our way of thinking, such as those who believe in astrology or creationism, so why should we treat these people with religious beliefs any differently? Because religious beliefs are beyond the scope of scientific inquiry, there is no more reason to discriminate against those with religious beliefs than there is to discriminate because of race, sexual preference, or political party. None of us would ever think of doing the latter, so why should anybody suggest the former?

Most of the local groups, including REALL and the New England Skeptical Society, officially profess the position of scientific skepticism. The compelling reason for this is that the definition of scientific skepticism provides a sound and internally consistent self-definition. Our roles are clearly defined-to defend science, to promote the scientific method as the best route to reliable knowledge about the universe, to challenge testable claims of a pseudoscientific, paranormal, or otherwise fringe nature, and to promote education, especially of science and critical thinking.

Without such a clearly defined focus, we risk being caught up in activities that may be only tangentially related to scientific skepticism. For example, the majority of our members probably oppose prayer in public schools, may support gay rights, and have strong feelings on abortion, but it is simply not the purpose of our organizations to expend our resources in such directions.

In addition, as a practical aspect to the focus on testable claims, our goal of teaching critical thinking and reason would be greatly hampered if we were perceived as being anti-religious. This single issue, which is not central to our purpose, could potentially drain our resources, monopolize our public image, and alienate many potential skeptics.

We should never be hesitant to scrutinize claims just because they have religious attachments-else we could not look at weeping icons, faith healers, Bible code finders, or fortunetellers who hang crosses in their windows. But systems of faith alone belong to the philosophers, not to the scientific skeptics like us.

The position of scientific skepticism is consistent, pragmatic, and allows the skeptical movement to precisely and confidently define the focus of its mission. Those who would prefer philosophical investigation have many other organizations to draw upon-including one that shares a headquarters building, and many members, with CSICOP. But CSICOP itself must stay true to its name and focus on scientific investigation.