Evidence and efficacy of homeopathy
This concept is inconsistent with the current understanding of matter, and water memory has never been demonstrated to exist, in terms of any detectable effect, biological or otherwise.
[9] There is an overall absence of sound statistical evidence of therapeutic efficacy, which is consistent with the lack of any biologically plausible pharmacological agent or mechanism.
[8] For comparison, ISO 3696:1987 defines a standard for water used in laboratory analysis; this allows for a contaminant level of ten parts per billion, 4C in homeopathic notation.
[36][37] In May 2018, the German skeptical organization GWUP issued an invitation to individuals and groups to respond to its challenge "to identify homeopathic preparations in high potency and to give a detailed description on how this can be achieved reproducibly."
[11] The methodological quality of the primary research was generally low, with such problems as weaknesses in study design and reporting, small sample size, and selection bias.
"[42] Government-level reviews have been conducted in recent years by Switzerland (2005), the United Kingdom (2009), Australia (2015) and the European Academies' Science Advisory Council (2017).
[51] In July 2017, as part of a plan to save £200m a year by preventing the "misuse of scarce" funding,[52] the NHS announced that it would no longer provide homeopathic medicines.
A small proportion of randomized controlled trials inevitably provide false-positive outcomes due to the play of chance: a statistically significant positive outcome is commonly adjudicated when the probability of it being due to chance rather than a real effect is no more than 5%―a level at which about 1 in 20 tests can be expected to show a positive result in the absence of any therapeutic effect.
[63] Both meta-analyses, which statistically combine the results of several randomized controlled trials, and other systematic reviews of the literature are essential tools to summarize evidence of therapeutic efficacy.
[65] Early systematic reviews and meta-analyses of trials evaluating the efficacy of homeopathic preparations in comparison with placebo more often tended to generate positive results, but appeared unconvincing overall.
"[72] Other meta-analyses include homeopathic treatments to reduce cancer therapy side-effects following radiotherapy and chemotherapy,[73] allergic rhinitis,[74][75] attention-deficit hyperactivity disorder and childhood diarrhoea, adenoid vegetation, asthma, upper respiratory tract infection in children,[76] insomnia,[77] fibromyalgia,[78] psychiatric conditions[79] and Cochrane Library systematic reviews of homeopathic treatments for asthma,[80] dementia,[81] attention-deficit hyperactivity disorder,[82] induction of labour,[83] upper respiratory tract infections in children,[84] and irritable bowel syndrome.
[85] Other reviews covered osteoarthritis,[86] migraines,[87] postoperative ecchymosis and edema,[88] delayed-onset muscle soreness,[89] preventing postpartum haemorrhage,[90] or eczema[91] and other dermatological conditions.
These 19 studies showed a pooled odds ratio of 1.17 to 2.23 in favour of individualized homeopathy over the placebo, but no difference was seen when the analysis was restricted to the methodologically best trials.
[15]: 209 A 2014 systematic review and meta-analysis found that individualized homeopathic remedies may be slightly more effective than placebos, though the authors noted that their findings were based on low- or unclear-quality evidence.
[100] Science offers a variety of explanations for how homeopathy may appear to cure diseases or alleviate symptoms even though the preparations themselves are inert:[15]: 155–167 While some articles have suggested that homeopathic solutions of high dilution can have statistically significant effects on organic processes including the growth of grain,[102] histamine release by leukocytes,[103] and enzyme reactions, such evidence is disputed since attempts to replicate them have failed.
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.
"[3][111][112] 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.
[111] In 2001 and 2004, Madeleine Ennis published a number of studies that reported that homeopathic dilutions of histamine exerted an effect on the activity of basophils.
[117] Edzard Ernst, the first professor of complementary medicine in the United Kingdom and a former homeopathic practitioner,[118][119][120] 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: Patients who choose to use homeopathy rather than evidence-based medicine risk missing timely diagnosis and effective treatment of serious conditions such as cancer.
[125][126] On September 30, 2016, the FDA issued a safety alert to consumers[127] warning against the use of homeopathic teething gels and tablets following reports of adverse events after their use.
The agency recommended that parents discard these products and "seek advice from their health care professional for safe alternatives"[128] to homeopathy for teething.
[133] 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;[134] 340 cases were settled out of court in 2006 for US$12 million.
[135] In 2009, the FDA advised consumers to stop using three discontinued cold remedy Zicam products because it could cause permanent damage to users' sense of smell.
[142] The Chief Medical Officer for England, Dame Sally Davies, has stated that homeopathic preparations are "rubbish" and do not serve as anything more than placebos.
[148] Jack Killen, acting deputy director of the National Center for Complementary and Alternative Medicine, says homeopathy "goes beyond current understanding of chemistry and physics".
[64] Homeopaths often prefer to ignore meta-analyses in favour of cherry picked positive results, such as by promoting a particular observational study (one which Goldacre describes as "little more than a customer-satisfaction survey") as if it were more informative than a series of randomized controlled trials.
[64] Referring specifically to homeopathy, the British House of Commons Science and Technology Committee has stated: In our view, the systematic reviews and meta-analyses conclusively demonstrate that homeopathic products perform no better than placebos.
[151]On clinical grounds, patients who choose to use homeopathy in preference to normal medicine risk missing timely diagnosis and effective treatment, thereby worsening the outcomes of serious conditions.
[153][162][163] This puts visitors to the tropics who take this advice in severe danger, since homeopathic preparations are completely ineffective against the malaria parasite.
[168] 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.
