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Early critiques of high dilutions
Sir John Forbes (1787-1861), physician to Queen Victoria (1841-61) said the extremely small doses were regularly derided as useless, laughably ridiculous and "an outrage to human reason." 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.". 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.
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 basis for them to have medicinal action. Some tests suggest that potentized solutions up to D120 can have statistically significant effects on organic processes, including the growth of grain, histamine release by leukocytes, and enzyme reactions. 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. 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.", 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, rats and humans.
Although some patients report benefits from homeopathic preparations, 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. However, many of the trials are open to technical criticism or involve samples that are too small to allow firm conclusions to be drawn.
Some homeopathic apologists 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" since homeopathy is positioned as a holistic treatment, incorporating psychological/spiritual concerns as well as an active ingredient. Some critics 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.
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 chemo-therapy. Three of the trials included were randomised double-blind placebo-controlled clinical trials. The authors were from the Department of Complementary Medicine at the Universities of Exeter and Plymouth. Their analysis found insufficient evidence to support the use of homeopathic remedies in cancer treatment recovery.
Lancet 2005 study
In August 2005, The Lancet published a meta-analysis of 110 placebo-controlled homoeopathy trials and 110 matched conventional-medicine trials based upon the Swiss government's Program for Evaluating Complementary Medicine, or PEK. The outcome of this meta-analysis suggested that the clinical effects of homeopathy are likely to be placebo effects. The Lancet paper is notable not least for its design, as another "global" meta analysis of homeopathy, not an analysis of particular effects, i.e. it tested the global hypothesis that the reported effects of homeopathy are placebo effects. If this is accurate, then the reported positive effects are due to placebo effects, publication bias, observer effects etc., and if so, then the magnitude of reported effects should diminish with sample size and study quality, and with the best studies there should be consistently no effect, and this is the prediction that the study sought to test. For comparison, they subjected an equal set of conventional medicine trials for identical analysis. These were matched for study disease and sample size, though a subsequent letter criticised the study for not matching trial quality, which was better in the homeopathic trials. The prediction was supported by the study - whereas the conventional tests showed a real effect independent of sample size, the homeopathy studies did not. The Lancet accompanied the meta-analysis with invited editorials.
British Medical Journal 1991 study
In 1991, three professors of medicine from the Netherlands, performed a meta-analysis of 25 years of clinical studies using homeopathic medicines and 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. 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." (Publication bias, also called the "file-drawer effect", refers to the tendency of scientists and journal editors to prefer to report and publish positive results, while negative or inconclusive results are more likely to end up buried in the bottom of the proverbial file drawer; it can cause a meta-analysis to report positive results when there is no underlying effect.)
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). However, other investigators failed to find any effect from these ultra-dilute solutions and suggested that methodological problems accounted for the positive results.
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." Therefore, systematic reviews with strict protocols are essential to establish proof for 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 insufficient evidence that homeopathy is beneficial for asthma, dementia, and induction of labor. They also found no evidence that homeopathic treatment can prevent influenza, but reported that it appears to shorten the duration of the disease. Systematic reviews conducted by other researchers found insufficient evidence that homeopathy is beneficial for osteoarthritis, migraine prophylaxis, delayed-onset muscle soreness, or symptoms of menopause.
Medical organizations' attitudes towards homeopathy
* The National Center for Complementary and Alternative Medicine, part of the U.S. National Institutes of Health, states that:
o 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." However, this implies a placebo was not actually used.
o "Systematic reviews have not found homeopathy to be a definitively proven treatment for any medical condition."
o A number of its key concepts defy chemistry, physics, and other sciences.
o It is uncertain how a remedy with so little, "perhaps not even one molecule" of its active ingredient could have any biological effect.
o Effects might be due to the placebo effect or similar non-specific effects.
o 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.
o 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.
o It continues to fund research into homeopathy.
* The UK National Health Service's "Health Encyclopedia" entry on homeopathy includes the following:
o 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.
o Medical doctors and scientists do not generally accept homeopathy because its claims have not been verified to the standards of modern medicine and 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.
* 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:
o 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.
* The Indian Department of Ayurveda, Yoga and Naturopathy, Unani, Siddha, and Homoeopathy states that:
o Homoeopathy today is a rapidly growing system and is being practiced almost all over the world. In India it has become a household name due the safety of its pills and gentleness of its cure.
o Homeopathy has been recognised as one of the National Systems of Medicine and plays an important role in providing health care to a large number of people. Its strength lies in its evident effectiveness as it takes a holistic approach towards the sick individual through promotion of inner balance at mental, emotional, spiritual and physical levels.
Regulatory decisions
In 2006 Australia's Therapeutic Goods Advertising Code Council (TGACC) found that a homeopathic Hangover Relief Oral Spray marketed by Brauer Natural Medicine P/L was "in breach of section 4(1)(b) of the Therapeutic Goods Advertising Code 2005 (the Code), which states that an advertisement must contain correct and balanced statements only and claims which the sponsor has already verified, and section 4(2)(c) which prohibits misleading advertisements."[119] The TGACC is established under Australian law and the Therapeutic Goods Advertising Code is generally consistent with the World Health Organisation's "Ethical Criteria For Medicinal Drug Promotion 1988"
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