What is it?
Homeopathy was invented in the late 18th and early 19th century by Samuel Hahnemann. While there is some variations in specific homeopathic practices, the fundamental system invented by Hahnemann is still the basis for modern homeopathy. In a time before scientific, evidence-based medical practices, doctors frequently did more harm than good with traditional but not systematically tested therapies like bleeding, purging, and the administration of toxic substances. Hahnemann recognized the lack of success, and even active harm, of contemporary treatments and tried to create an alternative.
He first came up with the so-called Law of Similars. This principle states that something which causes certain symptoms in a healthy person should be able to relieve those symptoms in a sick person. Hahnemann’s apparent basis for this idea was that when he or other healthy people took certain remedies used in his era to treat specific diseases, the healthy subjects seemed to develop symptoms similar to the disease the remedy was supposed to treat. No consistent evidence has ever been found to support this idea that like cures like. Furthermore, modern testing of agents used in some homeopathic remedies has not confirmed that they even cause the symptoms they are believed by homeopaths to cause.
Hahnemann reasoned that giving sick people substances which caused signs of illness in healthy people would probably do harm, so he decided these substances should be greatly diluted before being used as remedies. He even became convinced that the more one diluted a substance, the greater its curative power. Homeopathic remedies are generally diluted many hundred or thousands of times, and it has been clearly shown that most no longer contain even a single molecule of the original material used to make them. Homeopathic practitioners do not dispute this, but they claim that the water (or sometimes alcohol) used for dilution retains some mysterious memory of the substance and so can be used as a cure. Again, no reliable evidence exists that dilution strengthens a substance’s curative properties or that water retains a memory of something that it no longer contains.
Finally, Hahnemann believed that to make his diluted remedies truly effective, they had to be activated by succussion (vigorous shaking). This, in his words, made the substance “excited and able to act spiritually upon the vital forces.” The combined effect of dilution and succussion led, in Hahnemann’s view, to the potentization of the substance, making it an effective remedy.
Hahnemann did not believe diseases had physical causes, such as the bacteria, viruses, toxins, and other sources of illness recognized by science today. He saw diseases as ailments of the spirit rather than the body, and this idea still influences modern homeopathy. Many homeopaths dispute the very basis of science and medicine and prefer theories based on spiritual forces, mysterious undetectable energies, exotic interpretations of quantum mechanics, or semiotics. These practitioners argue that the scientific evidence against their claims is unimportant because they do not accept that scientific research is a useful way to determine if a medical therapy is safe or effective. They are frequently inconsistent in this, however, in that when they find a study which seems to support their practices, they are quick to publicize the fact.
Does It Work?
There is no reliable evidence to support the underlying concepts of homeopathy. No research has shown that like cures like, or that diluting and shaking a mixture gives it any special curative powers. Most homeopathic preparations are so dilute that even homeopaths acknowledge that no traces of the original substance used to make them can possibly remain. Numerous attempts have been made to find physical evidence for any change in the water or alcohol vehicle after dilution and succussion, but no such evidence has been found by any properly conducted, repeatable study.
The clinical studies of homeopathic treatments in human patients overwhelmingly demonstrate that such treatments are no better than a placebo. The best quality scientific studies require blinding, where the patients and researchers do not know whether each subject is getting the real treatment or a fake (placebo) treatment. And many other factors complicate interpretation of human clinical trials, so confidence in the results can only come from consistent, repeatable outcomes of numerous well-designed trials conducted by different investigators.
Multiple reviews over the last decade of the best quality studies, with reasonable numbers of subjects and good controls for bias, have found no benefit from homeopathic treatment beyond a placebo effect. Most telling is a 2005 review which compared homeopathic treatments to new, conventional pharmaceutical treatments for the same conditions. The homeopathic treatments showed marginal effects consistent with a placebo, whereas the conventional medicines showed clear, unequivocal effectiveness. This is an example why homeopathy is typically used only to treat chronic, naturally waxing and waning or self-limiting conditions with subjectively reported symptoms. Homeopathy is not generally applied to acute, life-threatening illnesses with objectively measurable signs that would not respond to a placebo treatment.
As is usually the case, the veterinary studies on homeopathy are few and of generally poor quality. While animals are not subject to the same psychological influences as human patients, the owners and veterinarians monitoring their symptoms are. The best veterinary studies of homeopathy, those that have been properly blinded or looked at objective laboratory measures of effect, have not found any benefit from homeopathic treatment.
Is it Safe?
Few direct harmful effects of homeopathic preparations have been reported. Those that are least diluted (less than 500 times) could conceivably contain traces of the original substance, and some allergic reactions to these have been seen in humans. This has not been reported in animals.
The primary danger of homeopathic treatment, however, is that it is often used in place of properly proven scientific diagnosis and treatment. This allows the disease and suffering of the patient to persist, and possibly to progress past the point where otherwise beneficial conventional treatment can be effective. And since many homeopaths reject the basic scientific explanations of disease or the legitimacy of scientific medical research, these individuals often recommend against conventional therapies, including medicines and immunization. This exposes patients to unnecessary risk and suffering.
Ø There is no evidence for the reality of the principles underlying homeopathy, such as the Law of Similars or the notion that diluting and shaking a substance gives it curative powers.
Ø The clinical research evidence in humans overwhelmingly demonstrates that homeopathic treatment is no more than a placebo, affecting a patient’s beliefs and feelings about their disease but not the disease itself.
Ø The clinical research evidence in animals is sparse and of poor quality. The best studies done to date show no benefit of homeopathic treatment.
Ø Homeopathic treatment by itself is unlikely to be harmful. However, since it has no real effect on the body and yet can create a perception of improvement in symptoms through the placebo effect, the use of homeopathy can delay legitimate scientific diagnosis and therapy, thus prolonging suffering and potentially denying the patient effective relief.
References and More Information
Barker Bausell, R., Snake Oil Science: The Truth About Complementary and Alternative Medicine, Oxford University Press, 2007
The North American Society of Homeopaths, Research and Philosophy Web Page, http://www.homeopathy.org/research.html#Philosophy
Ramey, D., Rollin, B., Complementary and Alternative Veterinary Medicine Considered, Iowa State Press, 2004
Saxton, J., Gregory, P., Textbook of Veterinary Homeopathy, Beaconsfield Publishers, 2005
Shang, A., et al., Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy. Lancet Aug-Sep 2005;366(9487):726-32
Sing, S., Ernst, E., Trick or Treatment: The Undeniable Facts About Alternative Medicine, W.W. Norton & Company, 2008
The Cochrane Collaboration, The Cochrane Reviews, a searchable database of systematic reviews of the human medical literature at http://www.cochrane.org/reviews/
© Brennen McKenzie, 2008