Talk:Homeopathy/Criticism
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[edit] Scientific critiques of homeopathic treatment
[edit] Early critiques of high dilutions
Sir John Forbes (1787-1861), physician to Queen Victoria (1841-61), said the extremely small doses of homeopathy were regularly derided as useless, laughably ridiculous and "an outrage to human reason."[1] Although such homeopathic cures were accepted as valid by regular physicians at the time, they were ascribed entirely to the body's innate healing powers. And Professor Sir James Young Simpson said of the highly diluted drugs: "no poison, however strong or powerful, the billionth or decillionth of which would in the least degree affect a man or harm a fly."[2]. Nineteenth century American physician and author Oliver Wendell Holmes, Sr. was a vocal critic of homeopathy and published an essay in 1842 entitled Homeopathy and Its Kindred Delusions.
[edit] British Medical Journal 1991 study
In 1991, three professors of medicine, Jos Kleijnen, Paul Knipschild and Gerben ter Riet from the Department of Epidemiology and Health Care Research at the University of Limburg, Maastricht in The Netherlands, performed a meta-analysis of 25 years of clinical studies using homeopathic medicines. They published their results in the British Medical Journal. This meta-analysis covered 107 controlled trials, of which 81 showed that homeopathic medicines were effective, 24 showed they were ineffective, and 2 were inconclusive.
The professors concluded, "The amount of positive results came as a surprise to us." They found evidence for successful treatment of respiratory and other infections, diseases of the digestive system, hay fever, rheumatological disease, mental or psychological problems and other ailments. In addition, they found evidence that homeopathic treatment helped patients recover after abdominal surgery and to address pain or trauma.
Despite the high percentage of studies that provided evidence of success with homeopathic medicine, most of these studies were flawed.[citation needed] Still, researchers found 22 high-caliber studies, 15 of which showed that homeopathic medicines were effective. Of further interest, they found that 11 of the best 15 studies showed efficacy.
The meta-analysis on homeopathy concluded, "At the moment the evidence of clinical trials is positive but not sufficient to draw definitive conclusions because most trials are of low methodological quality and because of the unknown role of publication bias. This indicates that there is a legitimate case for further evaluation of homoeopathy, but only by means of well performed trials."[3]
[edit] Lancet 2005 study
In August 2005, The Lancet medical journal published a meta-analysis of 110 placebo-controlled homoeopathy trials and 110 matched conventional-medicine trials[4] based upon the Swiss government's Program for Evaluating Complementary Medicine, or PEK. The outcome of this meta-analysis stated that the clinical effects of homeopathy are likely to be placebo effects.
This study is notable for its design, as a "global" meta analysis of homeopathy and not as an analysis of particular effects. It scientifically tested the global hypothesis that the reported effects of homeopathy are placebo effects. The hypothesis was that any reported positive effects of homeopathic treatments are probably due to placebo effects, publication bias, and observer effects, among others. Therefore, the magnitude of these reported positive effects of homeopathic treatments should diminish with sample size and study quality, with the best studies consistently showing no effect. The study tested this hypothesis. For comparison, a comparable set of conventional medical trials was subjected to an identical analysis. The homeopathic studies and the conventional medical trials were matched by disease type and sample size.
The Lancet study reported that the conventional tests showed a real effect independent of sample size, while the homeopathy studies did not, as would be expected if they were just due to assorted types of bias or statistical fluctuation. The Lancet accompanied the meta-analysis with invited editorials.
[edit] European Journal of Cancer 2006 study
In January 2006 the European Journal of Cancer published a meta-analysis of six trials of homeopathic treatments for recovery from cancer therapy, including radio- and chemotherapy.[5] Three of the trials included were randomised double-blind placebo-controlled clinical trials. The authors were from the Departments of Complementary Medicine at the Universities of Exeter and Plymouth. Their analysis found no evidence to support the use of homeopathic remedies in cancer treatment recovery.
[edit] Mechanism of action of homeopathic preparations
Since homeopathic remedies at potencies higher than about D23 (10-23) contain no detectable ingredients apart from the diluent (water, alcohol or sugar), there is no known chemical/scientific basis to date for them to have any medicinal action. Some tests suggest that potentized solutions up to D120 can have statistically significant effects on organic processes, including the growth of grain,[6] histamine release by leukocytes,[7][8] and enzyme reactions.[9] These publications are very controversial since attempts to replicate some of these studies on leukocytes and enzymes have failed, even when using the potentization method.[10][11][12][13] A recent review of tests of high potencies summarized the situation as follows: "...there are some hints from experimental research that homeopathic substances diluted and succussed beyond Avogadro's number are biologically active but there are no consistent effects from independently reproducible models.",[14] although the referenced journal is not generally regarded as being of high scientific quality.
These positive studies are unusual since no effects of high dilutions are seen in the huge number of similar studies on other biological systems. Here, low doses of chemicals give small effects and high doses large effects. This simple dose-response relationship has been confirmed in many hundreds of thousands of experiments on organisms as diverse as nematodes,[15] rats[16] and humans.[17]
Although some patients report benefits from homeopathic preparations,[18] the large majority of scientists attribute this to the placebo effect, the regression fallacy and/or the Forer effect. Ideally, drugs are tested in large, multi-centre, randomised, placebo-controlled double-blind clinical trials, to test whether the drug has an effect that is significantly better than a placebo or an alternative treatment. Many clinical trials that partially meet these criteria have investigated homeopathy, and some have indicated efficacy above placebo.[19] However, many of the trials are open to technical criticism or involve samples that are too small to allow firm conclusions to be drawn.[20]
Some advocates of homeopathy claim that orthodox double-blind trials are inherently insufficient for deriving evidence for the technique. For example, a spokeswoman from the UK Society of Homeopaths has said: "It has been established beyond doubt and accepted by many researchers, that the placebo-controlled randomised controlled trial is not a fitting research tool with which to test homeopathy"[21] since homeopathy is positioned as a holistic treatment, incorporating psychological/spiritual concerns as well as an active ingredient. Some critics[22] have noted that homeopathy includes falsifiable claims, even if that is only part of the homeopathic process, or simply that such claimed immunity from orthodox scientific scrutiny is reminiscent of pseudoscience.
[edit] Basophil stimulation
Madeleine Ennis, a pharmacologist at Queen's University Belfast, and her team looked at the effects of ultra-dilute solutions of histamine on human white blood cells involved in inflammation. These cells, called basophils, release histamine when they are stimulated. However, exposure to histamine stops these cells releasing any more, an example of negative feedback regulation. Three of the four participating groups observed this inhibitory effect with homeopathic solutions of histamine, solutions so dilute that they probably didn't contain a single histamine molecule. These low-dilution effects were seen in six of the 24 independent sets of experiments (Table 1 of paper).[23] A later investigation, attempting to replicate these results, failed to find any significant effect from these ultra-dilute solutions.[24]
[edit] Evidence-based medicine
There is widespread consensus in the medical community that evidence-based medicine is the best standard for assessing efficacy and safety of health-care practices, for it is "the expression of the scientific method in clinical medicine."[25] Therefore, systematic reviews with strict protocols are essential to establish the substantion of various therapies. While committed to this principle, much of modern medicine is subject to ongoing efforts to comply with evidence-based standards.
Systematic reviews conducted by the Cochrane Collaboration found no evidence that homeopathy is beneficial for asthma,[26] dementia,[27] and induction of labor.[28] They also found no evidence that homeopathic treatment can prevent influenza,[29] but reported that it appears to shorten the duration of the disease. Systematic reviews conducted by other researchers found no evidence that homeopathy is beneficial for osteoarthritis,[30] migraine prophylaxis,[31] delayed-onset muscle soreness,[32] or symptoms of menopause.[33]
[edit] Medical organizations' attitudes towards homeopathy
The National Center for Complementary and Alternative Medicine, part of the U.S. National Institutes of Health, states that:
- Results of individual, controlled clinical trials have been contradictory, with some saying it was no better than a placebo, with other trials having results "the researchers believed were greater than one would expect from a placebo."[34] However, this implies a placebo was not actually used.
- "Systematic reviews have not found homeopathy to be a definitively proven treatment for any medical condition."[34]
- A number of its key concepts defy chemistry, physics, and other sciences.[35]
- It is uncertain how a remedy with so little, "perhaps not even one molecule" of its active ingredient, could have any biological effect.[35]
- Effects might be due to the placebo effect or similar non-specific effects.[35]
- It is still largely untested whether it actually works for some of the diseases it's claimed to work for, and if it did work, how it would.
- NCAAM says that "there is a point of view" that it works, but is unexplained how, and that a lack of explanation is "not unique to homeopathy." It also says that some feel, as long as it seems "helpful and safe", no scientific explanation is necessary.[35]
- It continues to fund research into homeopathy.[36]
The UK National Health Service's "Health Encyclopedia" entry on homeopathy includes the following:
- Around 200 randomised controlled trials evaluating homeopathy have been conducted, and there are also several reviews of these trials. Despite the available research, no clinical evidence has shown that homeopathy works. Many studies suggest that any effectiveness that homeopathy may have is due to the placebo effect, where the act of receiving treatment is more effective than the treatment itself.[37]
- Medical doctors and scientists do not generally accept homeopathy because its claims have not been verified to the standards of modern medicine and the scientific method. Scientists argue that homeopathy cannot work because the remedies used are so highly diluted that in many there can be none of the active substance remaining.[38]
In 1997, the following statement was adopted as policy of the American Medical Association (AMA) after a report on a number of alternative therapies including homeopathy:[39]
- There is little evidence to confirm the safety or efficacy of most alternative therapies. Much of the information currently known about these therapies makes it clear that many have not been shown to be efficacious. Well-designed, stringently controlled research should be done to evaluate the efficacy of alternative therapies.
[edit] Homeopathy and The James Randi Million Dollar Challenge
Due to the lack of any concrete scientific evidence that homeopathy is any more effective than a placebo, the skeptic James Randi has included homeopathy in the list of candidates for his million dollar challenge. He will give a million dollars to anyone who can prove in a controlled, double-blind test, that homeopathy actually works. To date not a single person has done so.[40] However, in 1999 a multi-lab effort directed from France reported marginal-but-positive results.[41]. Following-up on this experiment, an international team led by Professor Madeleine Ennis of Queen's University Belfast claimed to have succeeded,[42]. Randi then forwarded the $1 million challenge to the BBC Horizon program to prove the "water memory" theory following Ennis' experimental procedure. In response, experiments were conducted with the Vice-President of the Royal Society, John Enderby, overseeing the proceedings. The challenge ended with the Horizon team failing to prove the memory of water.[43] However, Ennis claimed that Horizon did not faithfully reproduce her experiment.[44]
[edit] Safety of homeopathic treatment
The United States Food & Drug Administration considers that there is no real concern over the safety of most homeopathic products "because they have little or no pharmacologically active ingredients". There have been few reports of illness associated with the use of homeopathic products, but the medical literature contains a few case reports of poisoning by heavy metals such as arsenic[45] and mercury[46][47][48] found in homeopathic remedies. However, in cases that they reviewed, the FDA concluded the homeopathic product was not the cause of the adverse reactions. In one case, arsenic was implicated, although FDA analysis revealed that the concentration of arsenic was too low to cause concern. Perhaps the main concern about the safety of homeopathy arises not from the products themselves, but from the possible withholding of more efficacious treatment, or from misdiagnosis of dangerous conditions by a non-medically qualified homeopath.[49]
[edit] Delayed treatment
Because homeopathic preparations are available either over-the-counter in some countries or from unlicensed practitioners in others, patients may be attempting to treat a seriously illness that requires immediate medical attention. Because these preparations and remedies are named after the symptoms that are being treated, patients are misled into treating the symptoms rather than the underlying disease. Moreover, the symptom could be relieved by the placebo response, but the underlying medical issue remains untreated. With many disease, trauma or other medical states, delay in treatment will lead to severe health-care issues, including death.[50][51]
For example, a 2006 survey by the UK charitable trust Sense About Science revealed homeopathic practices that were advising travelers against taking conventional anti-malarial drugs, instead providing them with a homeopathic dilution of quinine.[52] Scientists and the Health Protection Agency have said the homeopaths' advice was reprehensible and likely to endanger lives.[53]
[edit] Wasted resources
Because of the expense of homeopathic treatments, and because most scientists and medical practitioners consider them placebos, the cost of the treatments plus consulting fees for the homeopathic practitioner is considered wasted money. In locations where healthcare costs are high or where reimbursements for healthcare costs are tightly regulated, money spent on these treatments could be better utilized for conventional medicine. However, in cases where the patient has a psychosomatic condition, the placebo effect of the homeopathic treatment may be beneficial to the psychological health of the patient.[51]
[edit] Nocebo effect
In clinical drug investigations, placebos should produce no apparent benefit to the patient, so that a valid comparison can be made between the drug and the placebo. Occasionally, a nocebo effect is observed with the placebo, in that it produces an apparent toxicity to the patient. In the case of homeopathic remedies, there has not been any systematic study of adverse reactions to these drugs. All homeopathic remedies should produce the same range of side effects as any other placebo.[51]
[edit] Vaccinations
Modern medicine strongly differs from the homeopathic beliefs regarding vaccines. A vaccine is usually a preparation made from an attenuated bacterium or virus that cannot cause disease, while still providing enough information to the immune system to induce a response to a future encounter with the same virus or bacteria.[54] By preparing the immune system of a healthy organism to meet a future attack by the pathogen, vaccination hopes to prevent disease, in contrast to homeopathy's hope, which is to prevent or cure it with dilutions. Another important difference is that vaccine contains measurable amounts of antigen, usually proteins or carbohydrates[55] from the disease-causing organism, whereas homeopathic remedies have been diluted to such an extent they are unlikely to contain any detectable active ingredients, because homeopathy rejects germ theory. Without antigen present in the vaccine, an immune response is not activated by the body, and it will not be protected from future encounters with the bacterial or viral pathogens.
