homeopathy

Homeopathy (also spelled Homoeopathy or Homœopathy) is a form of alternative medicine, first proposed by German physician Samuel Hahnemann in 1796, that treats patients with heavily diluted preparations which are thought to cause effects similar to the symptoms presented. Homeopathic remedies are prepared by serial dilution with shaking by forceful striking, which homeopaths term "succussion," after each dilution under the assumption that this increases the effect of the treatment. Homeopaths call this process "potentization". Dilution often continues until none of the original substance remains.^[1]

Apart from the symptoms of the disease, homeopaths use aspects of the patient's physical and psychological state in recommending remedies.^[2] Homeopathic reference books known as repertories are then consulted, and a remedy is selected based on the totality of symptoms. Homeopathic remedies are considered safe, with rare exceptions.^[3] However, some homeopaths have been criticized for putting patients at risk with advice to avoid conventional medicine such as vaccinations,^[4] anti-malarial drugs,^[5] and antibiotics.^[6] In many countries, the laws that govern the regulation and testing of conventional drugs do not apply to homeopathic remedies.^[7]

Claims of homeopathy's efficacy beyond the placebo effect are unsupported by the collective weight of scientific and clinical evidence.^{[8][9][10][11][12]} While some studies have positive results, systematic reviews of all the published trials fail to conclusively demonstrate efficacy.^{[13][14][15][16][17]} Furthermore, higher quality trials tend to report less positive results,^[15][18] and most positive studies have not been replicated or show methodological problems that prevent them from being considered unambiguous evidence of homeopathy's efficacy.^{[8][11][19][20]}

A homeopathic remedy prepared from marsh Labrador tea. The "15C" dilution shown here contains no molecules of the original herb.

Homeopathic remedies generally contain few or no pharmacologically active molecules,^[21] and for such remedies to have pharmacological effect would violate fundamental principles of science.^[12][22] Modern homeopaths have proposed that water has a memory that allows homeopathic preparations to work without any of the original substance; however, the physics of water are well understood, and no known mechanism permits such a memory.^[22][23] The lack of convincing scientific evidence supporting homeopathy's efficacy^[24] and its use of remedies lacking active ingredients have caused homeopathy to be described as pseudoscience or quackery.^{[25][26][27][28][29]}

General philosophy

Homeopathy is a vitalist philosophy in that it interprets diseases and sickness as caused by disturbances in a hypothetical vital force or life force. It sees these disturbances as manifesting themselves as unique symptoms. Homeopathy maintains that the vital force has the ability to react and adapt to internal and external causes, which homeopaths refer to as the "law of susceptibility". The law of susceptibility implies that a negative state of mind can attract hypothetical disease entities called "miasms" to invade the body and produce symptoms of diseases.^[30] However, Hahnemann rejected the notion of a disease as a separate thing or invading entity and insisted that it was always part of the "living whole".^[31]

Law of similars

Hahnemann observed from his experiments with cinchona bark, used as a treatment for malaria, that the effects he experienced from ingesting the bark were similar to the symptoms of malaria. He therefore reasoned that cure proceeds through similarity, and that treatments must be able to produce symptoms in healthy individuals similar to those of the disease being treated. Through further experiments with other substances, Hahnemann conceived of the "law of similars", otherwise known as "like cures like" (Latin: similia similibus curentur) as a fundamental healing principle. He believed that by inducing a disease through use of drugs, the artificial symptoms empowered the vital force to neutralise and expel the original disease and that this artificial disturbance would naturally subside when the dosing ceased.^[32]

Miasms and disease

In 1828, Hahnemann introduced the concept of miasms, which he regarded as underlying causes for many known diseases.^[33] A miasm is often defined by homeopaths as an imputed "peculiar morbid derangement of [the] vital force".^[34] Hahnemann associated each miasm with specific diseases, with each miasm seen as the root cause of several diseases. According to Hahnemann, initial exposure to miasms causes local symptoms, such as skin or venereal diseases, but if these symptoms are suppressed by medication, the cause goes deeper and begins to manifest itself as diseases of the internal organs.^[35] Homeopathy maintains that treating diseases by directly opposing their symptoms, as is sometimes done in conventional medicine, is ineffective because all "disease can generally be traced to some latent, deep-seated, underlying chronic, or inherited tendency".^[36] The underlying imputed miasm still remains, and deep-seated ailments can only be corrected by removing the deeper disturbance of the vital force.^[37]

Hahnemann's miasm theory remains disputed and controversial within homeopathy even in modern times. In 1978, Anthony Campbell, then a consultant physician at The Royal London Homeopathic Hospital, criticised statements by George Vithoulkas claiming that syphilis, when treated with antibiotics, would develop into secondary and tertiary syphilis with involvement of the central nervous system. This conflicts with scientific studies, which indicate that penicillin treatment produces a complete cure of syphilis in more than 90% of cases.^[38] Campbell described this as "a thoroughly irresponsible statement which could mislead an unfortunate layman into refusing orthodox treatment".^[6]

Originally Hahnemann presented only three miasms, of which the most important was "psora" (Greek for itch), described as being related to any itching diseases of the skin, supposed to be derived from suppressed scabies, and claimed to be the foundation of many further disease conditions. Hahnemann believed psora to be the cause of such diseases as epilepsy, cancer, jaundice, deafness, and cataracts.^[33] Since Hahnemann's time, other miasms have been proposed, some replacing one or more of psora's proposed functions, including tubercular miasms and cancer miasms.^[35]

Homeopathic remedies

Homeopathic remedy Rhus toxicodendron, derived from poison ivy.

"Remedy" is a technical term in homeopathy that refers to a substance prepared with a particular procedure and intended for treating patients. Homeopathic practitioners rely on two types of reference when prescribing remedies: Materia medica and repertories. A homeopathic Materia medica is a collection of "drug pictures", organised alphabetically by remedy, that describes the symptom patterns associated with individual remedies. A homeopathic repertory is an index of disease symptoms that lists remedies associated with specific symptoms.^[39]

Homeopathy uses many animal, plant, mineral, and synthetic substances in its remedies. Examples include Arsenicum album (arsenic oxide), Natrum muriaticum (sodium chloride or table salt), Lachesis muta (the venom of the bushmaster snake), Opium, and Thyroidinum (thyroid hormone). Homeopaths also use treatments called nosodes (from the Greek nosos, disease) made from diseased or pathological products such as fecal, urinary, and respiratory discharges, blood, and tissue.^[40] Homeopathic remedies prepared from healthy specimens are called Sarcodes.

Some modern homeopaths have considered more esoteric bases for remedies, known as "imponderables" because they do not originate from a material but from electromagnetic energy presumed to have been "captured" by alcohol or lactose. Examples include X-rays^[41] and sunlight.^[42] Recent ventures by homeopaths into even more esoteric substances include thunderstorms (prepared from collected rainwater).^[43] Today there are about 3,000 different remedies commonly used in homeopathy.^[44] Some homeopaths also use techniques that are regarded by other practitioners as controversial. These include paper remedies, where the substance and dilution are written on a piece of paper and either pinned to the patient's clothing, put in their pocket, or placed under a glass of water that is then given to the patient, as well as the use of radionics to prepare remedies. Such practices have been strongly criticised by classical homeopaths as unfounded, speculative, and verging upon magic and superstition.^[45][46]

Preparation of remedies

Mortar and pestle used for grinding insoluble solids into homeopathic remedies including quartz and oyster shells.

In producing remedies for diseases, homeopaths use a process called "dynamisation" or "potentisation" whereby a substance is diluted with alcohol or distilled water and then vigorously shaken by ten hard strikes against an elastic body in a process called "succussion". While Hahnemann advocated using substances which produce symptoms similar to those of the disease being treated, he found that material doses would intensify the symptoms and exacerbate the condition, sometimes causing what amounted to dangerous toxic reactions. He therefore specified that the substances be diluted. Hahnemann believed that the process of succussion activated the vital energy of the diluted substance.^[47] For this purpose, Hahnemann had a saddle maker construct a special wooden striking board covered in leather on one side and stuffed with horsehair.^[48][49] Insoluble solids, such as quartz and oyster shell, are diluted by grinding them with lactose (trituration).

Dilutions

Three potency scales are in regular use in homeopathy. Hahnemann created the centesimal or "C scale", diluting a substance by a factor of 100 at each stage. The centesimal scale was favored by Hahnemann for most of his life. A 2C dilution requires a substance to be diluted to one part in one hundred, and then some of that diluted solution diluted by a further factor of one hundred. This works out to one part of the original substance in 10,000 parts of the solution.^[50] A 6C dilution repeats this process six times, ending up with the original material diluted by a factor of 100⁻⁶=10⁻¹². Higher dilutions follow the same pattern. In homeopathy, a solution that is more dilute is described as having a higher potency, and more dilute substances are considered by homeopaths to be stronger and deeper-acting remedies.^[51] The end product is often so diluted that it is indistinguishable from the dilutant (pure water, sugar or alcohol).^[1][52][53]

Hahnemann advocated 30C dilutions for most purposes (that is, dilution by a factor of 10⁶⁰).^[54] In Hahnemann's time it was reasonable to assume that remedies could be diluted indefinitely, as the concept of the atom or molecule as the smallest possible unit of a chemical substance was just beginning to be recognized. We now know that the greatest dilution that is reasonably likely to contain one molecule of the original substance is 12C.

This bottle contains arnica montana (wolf's bane) D6, i.e. the nominal dilution is one part in a million (10⁶).

Some homeopaths developed a decimal scale (D or X), diluting the substance to ten times its original volume each stage. The D or X scale dilution is therefore half that of the same value of the C scale; for example, "12X" is the same level of dilution as "6C". Hahnemann never used this scale but it was very popular throughout the 19th century and still is in Europe. This potency scale appears to have been introduced in the 1830s by the American homeopath, Constantine Hering.^[55] In the last ten years of his life, Hahnemann also developed a quintamillesimal (Q) or LM scale diluting the drug 1 part in 50,000 parts of diluent.^[56] A given dilution on the Q scale is roughly 2.35 times its designation on the C scale. For example a remedy described as "20Q" has about the same concentration as a "47C" remedy.^[57]

Homeopathic remedy Oscillococcinum

Critics and advocates of homeopathy alike commonly attempt to illustrate the dilutions involved in homeopathy with analogies.^[59] Hahnemann is reported to have joked that a suitable procedure to deal with an epidemic would be to empty a bottle of poison into Lake Geneva, if it could be succussed 60 times.^[60][61] Another example given by a critic of homeopathy states that a 12C solution is equivalent to a "pinch of salt in both the North and South Atlantic Oceans",^[60][61] which is approximately correct.^[62] One third of a drop of some original substance diluted into all the water on earth would produce a remedy with a concentration of about 13C.^[63][59][64] A popular homeopathic treatment for the flu is a 200C dilution of duck liver, marketed under the name Oscillococcinum. As there are only about 10⁸⁰ atoms in the entire observable universe, a dilution of one molecule in the observable universe would be about 40C. Oscillococcinum would thus require 10³²⁰ more universes to simply have one molecule in the final substance.^[65] The high dilutions characteristically used are often considered to be the most controversial and implausible aspect of homeopathy.^[66]

Dilution debate

Not all homeopaths advocate extremely high dilutions. Many of the early homeopaths were originally doctors and generally used lower dilutions such as "3X" or "6X", rarely going beyond "12X". The split between lower and higher dilutions followed ideological lines. Those favoring low dilutions stressed pathology and a strong link to conventional medicine, while those favoring high dilutions emphasised vital force, miasms and a spiritual interpretation of disease.^[67][68] Some products with such relatively lower dilutions continue to be sold, but like their counterparts, they have not been conclusively demonstrated to have any effect beyond the placebo effect.^[69][70]

Provings

Hahnemann experimented on himself and others for several years before using remedies on patients. His experiments did not initially consist of giving remedies to the sick, because he thought that the most similar remedy, by virtue of its ability to induce symptoms similar to the disease itself, would make it impossible to determine which symptoms came from the remedy and which from the disease itself. Therefore, sick people were excluded from these experiments. The method used for determining which remedies were suitable for specific diseases was called "proving", after the original German word "Prüfung", meaning "test". A homeopathic proving is the method by which the profile of a homeopathic remedy is determined.^[71]

At first Hahnemann used material doses for provings, but he later advocated proving with remedies at a 30C dilution,^[54] and most modern provings are carried out using ultradilute remedies in which it is highly unlikely that any of the original molecules remain in any given dose.^[72] During the proving process, Hahnemann administered remedies to healthy volunteers, and the resulting symptoms were compiled by observers into a "Drug Picture". The volunteers were observed for months at a time and made to keep extensive journals detailing all of their symptoms at specific times throughout the day. They were forbidden from consuming coffee, tea, spices, or wine for the duration of the experiment; playing chess was also prohibited because Hahnemann considered it to be "too exciting", though they were allowed to drink beer and encouraged to exercise in moderation. After the experiments were over, Hahnemann made the volunteers take an oath swearing that what they reported in their journals was the truth, at which time he would interrogate them extensively concerning their symptoms.

Provings have been described as important in the development of the clinical trial, due to their early use of simple control groups, systematic and quantitative procedures, and some of the first application of statistics in medicine.^[73] The lengthy records of self-experimentation by homeopaths have occasionally proven useful in the development of modern drugs: For example, evidence that nitroglycerin might be useful as a treatment for angina was discovered by looking through homeopathic provings, though homeopaths themselves never used it for that purpose at that time.^[74] The first recorded provings were published by Hahnemann in his 1796 Essay on a new principle.^[75] His Fragmenta de viribus (1805)^[76] contained the results of 27 provings, and his 1810 Materia Medica Pura contained 65.^[77] For James Tyler Kent's 1905 Lectures on Homoeopathic Materia Medica, 217 remedies underwent provings and newer substances are continually added to contemporary versions.

Repertory

Homeopathic repertory by James Tyler Kent.

Homeopaths generally begin with detailed examinations of their patients' histories, including questions regarding their physical, mental and emotional states, their life circumstances and any physical or emotional illnesses. The homeopath then attempts to translate this information into a complex formula of mental and physical symptoms, including likes, dislikes, innate predispositions and even body type.^[78]

From these symptoms, the homeopath chooses how to treat the patient. A compilation of reports of many homeopathic provings, supplemented with clinical data, is known as a homeopathic materia medica. But because a practitioner first needs to explore the remedies for a particular symptom rather than looking up the symptoms for a particular remedy, the homeopathic repertory, which is an index of symptoms, lists after each symptom those remedies that are associated with it. Repertories are often very extensive and may include data extracted from multiple sources of materia medica. There is often lively debate among compilers of repertories and practitioners over the veracity of a particular inclusion.

The first symptomatic index of the homeopathic materia medica was arranged by Hahnemann. Soon after, one of his students Clemens von Bönninghausen, created the Therapeutic pocket book, another homeopathic repertory.^[79] The first such homeopathic repertory was Georg Jahr's Symptomenkodex, published in German (1835), which was then first translated to English (1838) by Constantine Hering as the Repertory to the more Characteristic Symptoms of Materia Medica. This version was less focused on disease categories and would be the forerunner to Kent's later works.^[80][40] It consisted of three large volumes. Such repertories increased in size and detail as time progressed.

Some diversity in approaches to treatments exists among homeopaths. "Classical" homeopathy generally involves detailed examinations of a patient's history and infrequent doses of a single remedy as the patient is monitored for improvements in symptoms, while "clinical" homeopathy involves combinations of remedies to address the various symptoms of an illness.^[81]

Related treatments

Isopathy

Isopathy is a therapy derived from homeopathy and was invented by Johann Joseph Wilhelm Lux in the 1830s.^[40] Isopathy differs from homeopathy in general in that the remedies are made up either from things that cause the disease, or from products of the disease, such as pus. Many so-called "homeopathic vaccines" are a form of isopathy.^[82]

Flower remedies

Flower remedies can be produced by placing flowers in water and exposing them to sunlight. The most famous of these are the Bach flower remedies, which were developed by the homeopath Edward Bach. Although the proponents of these remedies share homeopathy's vitalist world-view and the remedies are claimed to act through the same hypothetical "vital force" as homeopathy, the method of preparation is different. Bach flower remedies are prepared in "gentler" ways such as placing flowers in bowls of sunlit water, and the remedies are not succussed.^[83] There is no convincing scientific or clinical evidence for flower remedies being effective.^[84]

Veterinary use

The idea of using homeopathy as a treatment for other animals, termed veterinary homeopathy, dates back to the inception of homeopathy; Hahnemann himself wrote and spoke of the use of homeopathy in animals other than humans.^[85] The FDA has not approved homeopathic products as veterinary medicine in the U.S. In the UK, veterinary surgeons who use homeopathy belong to the Faculty of Homeopathy and/or to the British Association of Homeopathic Veterinary Surgeons. Animals may only be treated by qualified veterinary surgeons in the UK and some other countries. Internationally, the body that supports and represents homeopathic veterinarians is the International Association for Veterinary Homeopathy. The use of homeopathy in veterinary medicine is controversial, as there has been little scientific investigation and current research in the field is not of a high enough standard to provide reliable data.^[86] Other studies have also found that giving animals placebos can play active roles in influencing pet owners to believe in the effectiveness of the treatment when none exists.^[86]

Medical and scientific analysis

Homeopathy is unsupported by modern scientific research. The extreme dilutions used in homeopathic preparations usually leave none of the original material in the final product. The modern mechanism proposed by homeopaths, water memory, is considered implausible in that short-range order in water only persists for about 1 picosecond.^[87][88] Pharmacological effect without active ingredients is inconsistent with the observed dose-response relationships of conventional drugs,^[89] leaving only non-specific placebo effects^[9][90][91] or various novel explanations. The proposed rationale for these extreme dilutions – that the water contains the "memory" or "vibration" from the diluted ingredient – is counter to the laws of chemistry and physics, such as the law of mass action.^[87] The lack of convincing scientific evidence supporting its efficacy^[24] and its use of remedies without active ingredients have led to characterizations as pseudoscience and quackery,^{[25][27][28][92]} or, in the words of a 1998 medical review, "placebo therapy at best and quackery at worst."^[29] Use of homeopathy may delay or replace effective medical treatment, worsening outcomes or exposing the patients to increased risk.^{[4][6][11][93]}

High dilutions

The extremely high dilutions in homeopathy have been a main point of criticism. Homeopathic remedies are usually diluted to the point where there are no molecules from the original solution left in a dose of the final remedy.^[88] Homeopaths believe that the methodical dilution of a substance, beginning with a 10% or lower solution and working downwards, with shaking after each dilution, produces a therapeutically active "remedy", in contrast to therapeutically inert water. Since even the longest-lived noncovalent structures in liquid water at room temperature are only stable for a few picoseconds,^[94] critics have concluded that any effect that might have been present from the original substance can no longer exist.^[95] No evidence of stable clusters of water molecules was found when homeopathic remedies were studied using NMR.^[96]

Furthermore, since water will have been in contact with millions of different substances throughout its history, critics point out that water is therefore an extreme dilution of almost any conceivable substance. By drinking water one would, according to this interpretation, receive treatment for every imaginable condition.^[97]

Practitioners of homeopathy contend that higher dilutions produce stronger medicinal effects. This idea is inconsistent with the observed dose-response relationships of conventional drugs, where the effects are dependent on the concentration of the active ingredient in the body.^[89] This dose-response relationship has been confirmed in multitudinous experiments on organisms as diverse as nematodes,^[98] rats,^[99] and humans.^[100]

Physicist Robert L. Park, former executive director of the American Physical Society, has noted that

Park has also noted that "to expect to get even one molecule of the 'medicinal' substance allegedly present in 30X pills, it would be necessary to take some two billion of them, which would total about a thousand tons of lactose plus whatever impurities the lactose contained".

The laws of chemistry state that there is a limit to the dilution that can be made without losing the original substance altogether.^[21] This limit, which is related to Avogadro's number, is roughly equal to homeopathic potencies of 12C or 24X (1 part in 10²⁴).^{[59][90][102]}

Scientific tests run by both the BBC's Horizon and ABC's 20/20 programs were unable to differentiate homeopathic dilutions from water, even when using tests suggested by homeopaths themselves.^[49][103]

Research on medical effectiveness

Old bottle of Hepar sulph made from calcium sulfide

The effectiveness of homeopathy has been in dispute since its inception. The methodological quality of the research base is generally low, with such problems as weaknesses in design or reporting, small sample size, and selection bias. No individual preparation has been unambiguously demonstrated to be different from a placebo.^[8][104]

Positive results have been reported, but no single model has been sufficiently widely replicated. Local models proposed are far from convincing, and the nonlocal models proposed, often invoking "weak quantum theory",^[105] would predict that it is impossible to nail down homeopathic effects with direct experimental testing.^[106] For example, while some reports presented data that suggested homeopathic treatment of allergy was more effective than placebo,^[107][108] subsequent studies have questioned the conclusions.^[109][110] One of the earliest double blind studies concerning homeopathy was sponsored by the British government during World War II in which volunteers tested the effectiveness of homeopathic remedies against diluted mustard gas burns.^[111]

Meta-analyses, in which large groups of studies are analysed and conclusions drawn based on the results as a whole, have been used to evaluate the effectiveness of homeopathy. Early meta-analyses investigating homeopathic remedies showed slightly positive results among the studies examined, but such studies have warned that it was impossible to draw firm conclusions due to low methodological quality and difficulty in controlling for publication bias in the studies reviewed.^{[13][20][112]} One of the positive meta-analyses, by Linde, et al.,^[112] was later qualified by the authors, who wrote:

The evidence of bias [in homeopathic trials] weakens the findings of our original meta-analysis. Since we completed our literature search in 1995, a considerable number of new homeopathy trials have been published. The fact that a number of the new high-quality trials... have negative results, and a recent update of our review for the most “original” subtype of homeopathy (classical or individualized homeopathy), seem to confirm the finding that more rigorous trials have less-promising results. It seems, therefore, likely that our meta-analysis at least overestimated the effects of homeopathic treatments.^[12][15]

In 2001, a meta-analysis of clinical trials on the effectiveness of homeopathy concluded that earlier clinical trials showed signs of major weakness in methodology and reporting, and that homeopathy trials were less randomized and reported less on dropouts than other types of trials.^[20]

In 2002, a review of systematic reviews found that higher-quality trials tended to have less positive results, to the point that those results were clinically irrelevant. Also, when taking collectively all the systematic reviews, there was no convincing evidence that any homeopathic remedy had better effects than placebo, and current evidence did not allow to recommend its usage in clinical treatment.^[8]

In 2005, a systematic review of the representation of homeopathy in the medical literature suggested that mainstream journals had a publication bias against clinical trials of homeopathy that showed positive results, and the opposite was the case for complementary and alternative medicine journals. The authors suggested that this could be due to an involuntary bias, or otherwise a submission bias, in which positive trials tend to be sent to CAM journals and negatives ones to mainstream journals.^[18] Reviews in all journals approached the subject in an apparently impartial manner, though most of the reviews published in CAM journals made no mention of the plausibility of homeopathy, whereas 9 out of 10 reviews in mainstream journals mentioned a lack of plausibility of homeopathy in the introduction.^[18]

In 2005, The Lancet medical journal published a meta-analysis of 110 placebo-controlled homeopathy trials and 110 matched medical trials based upon the Swiss government's Program for Evaluating Complementary Medicine, or PEK. The study concluded that its findings were compatible with the notion that the clinical effects of homeopathy are nothing more than placebo effects.^[12]

A 2006 meta-analysis of six trials evaluating homeopathic treatments to reduce cancer therapy side effects following radiotherapy and chemotherapy found "encouraging but not convincing" evidence in support of homeopathic treatment. Their analysis concluded that there was "insufficient evidence to support clinical efficacy of homeopathic therapy in cancer care".^[113]

A 2007 systematic review of homeopathy for children and adolescents found that the evidence for attention-deficit hyperactivity disorder and childhood diarrhea was mixed. No difference from placebo was found for adenoid vegetation, asthma, or upper respiratory tract infection. Evidence was not sufficient to recommend any therapeutic or preventative intervention.^[11]

The Cochrane Library found insufficient clinical evidence to evaluate the efficacy of homeopathic treatments for asthma^[114] or dementia,^[115] or for the use of homeopathy in induction of labor.^[116] Other researchers found no evidence that homeopathy is beneficial for osteoarthritis,^[117] migraines^[118] or delayed-onset muscle soreness.^[81]

Health organisations such as the UK's National Health Service,^[119] the American Medical Association,^[10] and the FASEB^[95] have issued statements of their conclusion that there is no convincing scientific evidence to support the use of homeopathic treatments in medicine.

Clinical studies of the medical efficacy of homeopathy have been criticised by some homeopaths as being irrelevant because they do not test "classical homeopathy".^[120][121] There have, however, been a number of clinical trials that have tested individualized homeopathy. A 1998 review^[122] found 32 trials that met their inclusion criteria, 19 of which were placebo-controlled and provided enough data for meta-analysis. These 19 studies showed a pooled odds ratio of 1.17 to 2.23 in favor of individualized homeopathy over the placebo, but no difference was seen when the analysis was restricted to the methodologically best trials. The authors concluded "that the results of the available randomized trials suggest that individualized homeopathy has an effect over placebo. The evidence, however, is not convincing because of methodological shortcomings and inconsistencies."

Jack Killen, acting deputy director of the National Center for Complementary and Alternative Medicine, says homeopathy "goes beyond current understanding of chemistry and physics." He adds: "There is, to my knowledge, no condition for which homeopathy has been proven to be an effective treatment."^[24]

Research on effects in other biological systems

Old homeopathic belladonna remedy.

While some articles have suggested that homeopathic solutions of high dilution can have statistically significant effects on organic processes including the growth of grain,^[123] histamine release by leukocytes,^[124] and enzyme reactions, such evidence is disputed since attempts to replicate them have failed.^{[125][126][127][128][129]}

In 1987, French immunologist Jacques Benveniste submitted a paper to the journal Nature while working at INSERM. The paper purported to have discovered that basophils, a type of white blood cell, released histamine when exposed to a homeopathic dilution of anti-immunoglobulin E antibody. The journal editors, sceptical of the results, requested that the study be replicated in a separate laboratory. Upon replication in four separate laboratories the study was published. Still sceptical of the findings, Nature assembled an independent investigative team to determine the accuracy of the research, consisting of Nature editor and physicist Sir John Maddox, American scientific fraud investigator and chemist Walter Stewart, and sceptic and magician James Randi. After investigating the findings and methodology of the experiment, the team found that the experiments were "statistically ill-controlled", "interpretation has been clouded by the exclusion of measurements in conflict with the claim", and concluded, "We believe that experimental data have been uncritically assessed and their imperfections inadequately reported."^{[23][130][131]} James Randi stated that he doubted that there had been any conscious fraud, but that the researchers had allowed "wishful thinking" to influence their interpretation of the data.^[130]

Methodological and publication issues

Ben Goldacre published an article on homeopathy in The Lancet, stating the research on homeopathy is problematic for a variety of reasons. These included the high publication biases of alternative therapy journals, with very few articles reporting null results; ignoring meta-analytic studies in favour of cherry picked positive results; and the promotion of an observational study (that Goldacre described as "little more than a customer-satisfaction survey") as if it were more informative than a series of randomized trials. Goldacre also states that homeopaths who misrepresent scientific evidence to a scientifically illiterate public, have "...walled themselves off from academic medicine, and critique has been all too often met with avoidance rather than argument."^[132]

Ethical and safety issues

As homeopathic remedies usually contain only water and/or alcohol, they are thought to be generally safe. Only in rare cases are the original ingredients present at detectable levels. This may be due to improper preparation or intentional low dilution. Instances of arsenic poisoning have occurred after use of arsenic-containing homeopathic preparations.^[3] Zicam Cold Remedy Nasal Gel, which contains 2X (1:100) zinc gluconate, reportedly caused a small percentage of users to lose their sense of smell;^[133] 340 cases were settled out of court in 2006 for 12 million U.S. dollars.^[134] In 2009, the FDA advised consumers to stop using three discontinued cold remedy products manufactured by Zicam because it could cause permanent damage to users' sense of smell.^[135] Zicam was launched without a New Drug Application (NDA) under a provision in the FDA’s Compliance Policy Guide called "Conditions Under Which Homeopathic Drugs May be Marketed" (CPG 7132.15), but the FDA warned Zicam that this policy does not apply when there is a health risk to consumers.^[136]

Critics of homeopathy have cited other concerns over homeopathic medicine, most seriously cases of patients of homeopathy failing to receive proper treatment for diseases that could have been easily diagnosed and managed with conventional medicine and who have died as a result^[137] and the "marketing practice" of criticizing and downplaying the effectiveness of mainstream medicine.^[132] Homeopaths claim that use of conventional medicines will "push the disease deeper" and cause more serious conditions, a process referred to as "suppression".^[138][139] Some homeopaths (particularly those who are non-physicians) advise their patients against immunisation.^{[4][140][141]} Some homeopaths suggest that vaccines be replaced with homeopathic "nosodes", created from biological material such as pus, diseased tissue, bacilli from sputum or (in the case of "bowel nosodes") feces.^[142] While Hahnemann was opposed to such preparations, modern homeopaths often use them although there is no evidence to indicate they have any beneficial effects.^[143][144] Cases of homeopaths advising against the use of anti-malarial drugs have been identified.^{[5][145][146]} This puts visitors to the tropics who take this advice in severe danger, since homeopathic remedies are completely ineffective against the malaria parasite.^{[5][145][146]} Also, in one case in 2004, a homeopath instructed one of her patients to stop taking conventional medication for a heart condition, advising her on 22 June 2004 to "Stop ALL medications including homeopathic", advising her on or around 20 August that she no longer needed to take her heart medication, and adding on 23 August, "She just cannot take ANY drugs – I have suggested some homeopathic remedies ... I feel confident that if she follows the advice she will regain her health." The patient was admitted to hospital the next day, and died eight days later, the final diagnosis being "acute heart failure due to treatment discontinuation".^[147][148]

In 1978, Anthony Campbell, then a consultant physician at The Royal London Homeopathic Hospital, criticised statements made by George Vithoulkas to promote his homeopathic treatments. Vithoulkas stated that syphilis, when treated with antibiotics, would develop into secondary and tertiary syphilis with involvement of the central nervous system. Campbell described this as a thoroughly irresponsible statement which could mislead an unfortunate layman into refusing conventional medical treatment.^[6] This claim echoes the idea that treating a disease with external medication used to treat the symptoms would only drive it deeper into the body and conflicts with scientific studies, which indicate that penicillin treatment produces a complete cure of syphilis in more than 90% of cases.^[38]

A 2006 review by W. Steven Pray of the College of Pharmacy at Southwestern Oklahoma State University recommends that pharmacy colleges include a required course in unproven medications and therapies, that ethical dilemmas inherent in recommending products lacking proven safety and efficacy data be discussed, and that students should be taught where unproven systems such as homeopathy depart from evidence-based medicine.^[149]

Edzard Ernst, the first Professor of Complementary Medicine in the United Kingdom, has expressed his concerns about pharmacists who violate their ethical code by failing to provide customers with "necessary and relevant information" about the true nature of the homeopathic products they advertise and sell:

"My plea is simply for honesty. Let people buy what they want, but tell them the truth about what they are buying. These treatments are biologically implausible and the clinical tests have shown they don't do anything at all in human beings. The argument that this information is not relevant or important for customers is quite simply ridiculous."^[150]

Regulation and prevalence

Hampton House, the former site of Bristol Homeopathic Hospital, one of a handful of homeopathic hospitals run by the NHS.

Homeopathy is fairly common in some countries while being uncommon in others; is highly regulated in some countries and mostly unregulated in others. It is practised worldwide and professional qualifications and licences are needed in most countries.^[7] Regulations vary in Europe depending on the country. In some countries, there are no specific legal regulations concerning the use of homeopathy, while in others, licences or degrees in conventional medicine from accredited universities are required. In Germany, no specific regulations exist, while France, Austria and Denmark mandate licences to diagnose any illness or dispense of any product whose purpose is to treat any illness.^[7] Some homeopathic treatment is covered by the public health service of several European countries, including France, the United Kingdom, Denmark, and Luxembourg. In other countries, such as Belgium, homeopathy is not covered. In Austria, the public health service requires scientific proof of effectiveness in order to reimburse medical treatments and homeopathy is listed as not reimbursable^[151] but exceptions can be made;^[152] private health insurance policies sometimes include homeopathic treatment.^[7] The Swiss government, after a 5-year trial, withdrew homeopathy and four other complementary treatments in 2005, stating that they did not meet efficacy and cost-effectiveness criteria.^[153] The Indian government includes homeopathy as a part of the national health system and homeopaths are considered medical professionals there. Conventional (Western) medical science is referred to in India as "allopathy" and its practitioners are called allopaths.^[154]

In the United Kingdom, MPs recently announced an inquiry into homeopathy to assess the Government's policy on the issue, including funding of homeopathy under the National Health Service and government policy for licensing homeopathic products. The decision by the House of Commons Science and Technology Committee follows a written explanation from the Government in which it told the select committee that the licensing regime was not formulated on the basis of scientific evidence. "The three elements of the licensing regime (for homeopathic products) probably lie outside the scope of the ... select committee inquiry, because government consideration of scientific evidence was not the basis for their establishment," the Committee said. The inquiry is seeking written evidence and submissions from concerned parties.^[155][156]

History

1857 painting by Alexander Beydeman showing historical figures and personifications of homeopathy observing the perceived brutality of medicine of the 19th century

Historical context

In the 16th century the pioneer of chemical medicine Paracelsus declared that small doses of “what makes a man ill also cures him", anticipating homeopathy,^[157] but it was Hahnemann who gave it a name and laid out its principles in the late 18th century. At that time, mainstream medicine employed such measures as bloodletting and purging, used laxatives and enemas, and administered complex mixtures, such as Venice treacle, which was made from 64 substances including opium, myrrh, and viper's flesh.^[158][159] Such measures often worsened symptoms and sometimes proved fatal.^[160][161] While the virtues of these treatments had been extolled for centuries,^[162] Hahnemann rejected such methods as irrational and inadvisable.^[163] Instead, he favored the use of single drugs at lower doses and promoted an immaterial, vitalistic view of how living organisms function, believing that diseases have spiritual, as well as physical causes.^[31][164] (At the time, vitalism was part of mainstream science; in the 20th century, however, medicine discarded vitalism, with the development of microbiology, the germ theory of disease,^[165] and advances in chemistry.^[166][167]) Hahnemann also advocated various lifestyle improvements to his patients, including exercise, diet, and cleanliness.^[163][168]

Hahnemann's concept

Samuel Hahnemann, considered to be the father of homeopathy

Hahnemann conceived of homeopathy while translating a medical treatise by Scottish physician and chemist William Cullen into German.^[32] Being skeptical of Cullen's theory concerning cinchona's action in malaria, Hahnemann ingested some of the bark specifically to see if it cured fever "by virtue of its effect of strengthening the stomach".^[169] Upon ingesting the bark, he noticed few stomach symptoms, but did experience fever, shivering and joint pain, symptoms similar to some of the early symptoms of malaria, the disease that the bark was ordinarily used to treat. From this, Hahnemann came to believe that all effective drugs produce symptoms in healthy individuals similar to those of the diseases that they treat. This later became known as the "law of similars", the most important concept of homeopathy.^[32] The term "homeopathy" was coined by Hahnemann and first appeared in print in 1807, although he began outlining his theories of "medical similars" in a series of articles and monographs in 1796.^[170]

Hahnemann began to test what effects substances produced in humans, a procedure which would later become known as "homeopathic proving".^[171] These time-consuming tests required subjects to clearly record all of their symptoms as well as the ancillary conditions under which they appeared. Hahnemann saw these data as a way of identifying substances suitable for the treatment of particular diseases.^[171] The first collection of provings was published in 1805 and a second collection of 65 remedies appeared in his book, Materia Medica Pura, in 1810.^[172] Hahnemann believed that large doses of drugs that caused similar symptoms would only aggravate illness, so he advocated extreme dilutions of the substances; he devised a technique for making dilutions that he believed would preserve a substance's therapeutic properties while removing its harmful effects,^[1] proposing that this process aroused and enhanced "spirit-like medicinal powers held within a drug".^[173] He gathered and published a complete overview of his new medical system in his 1810 book, The Organon of the Healing Art, whose 6th edition, published in 1921, is still used by homeopaths today.^[32]

Rise to popularity and early criticism

Homeopathy achieved its greatest popularity in the 19th century. Dr. John Franklin Gray (1804–1882) was the first practitioner of Homeopathy in the United States, beginning in 1828 in New York City. The first homeopathic schools opened in 1830, and throughout the 19th century dozens of homeopathic institutions appeared in Europe and the United States.^[174] By 1900, there were 22 homeopathic colleges and 15,000 practitioners in the United States.^[19] Because of then-current medicine's reliance on ineffective and often dangerous treatments, patients of homeopaths often had better outcomes than those of the doctors of the time.^[175] Homeopathic remedies, even if ineffective, would almost surely cause no harm, making the users of homeopathic remedies less likely to be killed by the treatment that was supposed to be helping them.^[32] The relative success of homeopathy in the 19th century may have led to the abandonment of the ineffective and harmful treatments of bloodletting and purging and to have begun the move towards more effective, science based medicine.^[161] One reason for the growing popularity of homeopathy was its apparent success in treating people suffering from infectious disease epidemics.^[176] During 19th century epidemics of diseases such as cholera, death rates in homeopathic hospitals were often lower than in conventional hospitals, where the treatments used at the time were often harmful and did little or nothing to combat the diseases.^[177]

From its inception, however, homeopathy was criticized by mainstream science. Sir John Forbes, physician to Queen Victoria, said the extremely small doses of homeopathy were regularly derided as useless, "an outrage to human reason".^[178] 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."^[179] 19th century American physician and author Oliver Wendell Holmes, Sr. was also a vocal critic of homeopathy and published an essay in 1842 entitled Homœopathy, and its kindred delusions.^[180] The members of the French Homeopathic Society observed in 1867 that some of the leading homeopathists of Europe were not only abandoning the practice of administering infinitesimal doses, but were also no longer defending it.^[181] The last school in the U.S. exclusively teaching homeopathy closed in 1920.^[32]

Revival in the late 20th Century

The Food, Drug, and Cosmetic Act of 1938 (sponsored by New York Senator and Homeopathic Physician Royal Copeland) recognized homeopathic remedies as drugs. By the 1950s there were only 75 pure homeopaths practicing in the U.S.^[182] However, in the mid to late 1970s, homeopathy made a significant comeback and sales of some homeopathic companies increased tenfold.^[183] Greek homeopath George Vithoulkas performed a "great deal of research to update the scenarios and refine the theories and practice of homeopathy" beginning in the 1970s, and it was revived worldwide;^[81][184] for example, Brazil in the 1970s and Germany in the 1980s.^[185] The medical profession started to integrate such ideas in the 1990s^[186] and mainstream pharmacy chains recognized the business potential of selling homeopathic remedies.^[187]

See also

• List of homeopathic preparations
• Electrohomeopathy
• Placebo
• Quackery

Notes and references

External links

Associations and regulatory bodies

• Homeopathy organizations at the Open Directory Project

Other links

Wikinews has related news: Parents prosecuted after homeopathic treatment leads to daughter's death

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• "Questions and answers about homeopathy", National Center for Complementary and Alternative Medicine (NCCAM), April 2003, http://nccam.nih.gov/health/homeopathy/, retrieved 2009-01-09 National Institutes of Health Research Report
• Barrett S, "HomeoWatch: Your skeptical guide to homeopathic history, theories, and current practices", http://www.homeowatch.org/ 
• Ramey DW (January 2000), "The scientific evidence on homeopathy", American Council on Science and Health, http://www.acsh.org/healthissues/newsID.632/healthissue_detail.asp, retrieved 2009-01-09 
• Ameke W, Drysdale AE (tr), Dudgeon RE (ed) (1885), History of homœopathy, with an appendix on the present state of University medicine, London: E. Gould & Son, http://homeoint.org/seror/ameke/index.htm 
• Randi J, "Homeopathy Explained" (Video (14 min 34 sec)]), http://video.google.ca/videoplay?docid=2785985155605802136&q=James+Randi  - Portion of 2001 Princeton lecture. (Complete 2 hr 10 min 43 sec lecture.)
• Langone J (18 September 1996), "Challenging the mainstream", Time, http://www.time.com/time/magazine/article/0,9171,985153,00.html, retrieved 2009-01-09 
• Fisher P, Goldacre B (30 November 2006), "Does homeopathy work?", http://www.nhm.ac.uk/nature-online/life/plants-fungi/homeopathic-medicine/index.html, retrieved 2009-01-09  A debate on the evidence on both sides with Peter Fisher, Clinical Director of the Royal London Homeopathic Hospital and Ben Goldacre, medical writer and broadcaster.