Homeopathy is one of the most debated medical methods. Proponents claim that it is effective and—unlike conventional medical methods—has no side effects. Skeptics say that homeopathy is nothing but a placebo, as the substances used in
Fig. 3.12 The hydrolysis of
sucrose to yield D-glucose and D-fructose. (Authors’ own work)
145 3.9 Homeopathy: No Active Ingredient? No Side Effect?
treatments do not have any active ingredients. It is not easy to do this topic justice here, but trying to do so is not entirely without merit.
Homeopathy originated at the end of the eighteenth century, with its founding fa- ther, German physician Samuel Hahnemann (1755–1843), who rejected contempo- rary medical practices that caused great amounts of suffering to patients (bloodlet- ting was one of the least intrusive). He attempted to find cures that alleviated symp- toms with lower-intensity or fewer unpleasant effects. He conceived of the idea of homeopathy when he was translating a medical book, which stated that the bark of cinchona tree could be used to treat malaria. Hahnemann began experimenting on himself and found that cinchona caused malaria-like symptoms in his otherwise healthy body. This experience was the root of why Hahnemann believed that testing medicines on healthy people was extremely important. His healing principle was: “that which can produce a set of symptoms in a healthy individual, can treat a sick individual who is manifesting a similar set of symptoms.” So homeopathy means healing by similarity, ‘like cures like’. The word itself comes from Greek: hómoios- (ὅμοιος-) means “like–” and páthos (πάθος) means “suffering”.
Later on, Hahnemann began testing what effects different substances produced in humans, a procedure that would later become known as “homeopathic prov- ing”. His theory postulated that the symptoms of “overdosing” can be removed by lowering the dose, but the therapeutic effects can be preserved. To reach this goal, he developed the method of “potentization”, whereby a substance was diluted in a number of successive steps (Fig. 3.13). Dilution steps with a factor of ten, one hundred and fifty thousand were labeled D (decimal), C (centimal), and Q (quinque millessima = 50,000). The number of dilution steps is given as a digit after the letter. The dilution is done with water for liquids, whereas lactose is used for solids. The process of “dynamization” or “potentization” has to follow certain rules (vigorous shaking, striking against an elastic body) in a process homeopaths call “succus- sion”. The objective of these rules is to increase the efficacy of the substance, so believers assert that the final product is much more than simply a dilute solution or powder.
Homeopathy often uses extremely diluted substances (which are conversely said to be of high potential). A C30 homeopathic remedy is prepared by 30 successive hundredfold dilutions, such that the final solutions contains the “active ingredient” diluted by a factor of 10030. This means such a product is very unlikely to contain
even a single molecule of the active substance. As an example, a quite sweet solu- tion of sucrose with a concentration of 342 g/l or 1 mol/dm3 contains 6 × 1023 sugar
molecules in a liter. Dilution with a factor of 1024 will produce a solution that is un-
likely to contain even a single molecule of sugar in a liter. With homeopathic word- ing, this would be D24 or C12 dilution. Homeopathic practice in fact uses products with even higher potential, whose content of active ingredients is also 0 molecules. Opponents often point out that such a product is nothing but water or lactose, so the effect is actually the same as the placebo effect. In the following paragraphs, some examples will be given to paint a more detailed picture about the problem of active ingredients in homeopathy.
146 3 Medicines
About two thirds of the substances used in homeopathy come from plants. It is often the entire above-ground plant, but occasionally only a few select parts. The raw material is first used to prepare a “mother tincture”, which is further processed. Another large group of homeopathic products are based on minerals, including metals such as gold or silver and some inorganic elements such as sulfur. Animal- derived substances (from insects, snakes) form a much smaller group, but are not insignificant, either. Homeopaths also use treatments called “nosodes” (from the Greek ‘nosos’, νόσος, disease) made from diseased or pathological materials such as fecal, urinary, and respiratory discharges, blood, tissue, bacteria, viruses, fungi, parasites or other pathogens.
Homeopathic products have a unique status in the health marketplace. They are marketed as drugs in many countries. In the US, the 1938 Federal Food, Drug, and Cosmetic Act, which passed Congress with the active support of a senator who was also a homeopathic physician, recognized all substances in the Homeopathic Phar- macopeia of the United States as drugs. The Food and Drug Administration (FDA) of the US does not require the same standards from homeopathic products as from other drugs. In many countries, the legal situation is very similar. The quality of the products is usually carefully controlled, but even if they contain only a single active ingredient at high dilutions, it is not necessary to prove medical efficacy. As a consequence, most of them do not have officially accepted therapeutic recom- mendations.
Despite the general trends, a small percentage of “homeopathic” medicines actu- ally have such recommendations. In specific cases, these uses must be supported by tests on patients in the same way as for standard drugs. Many of these exceptional homeopathic drugs share the characteristics contained in their mother tinctures or their low dilutions, e.g. D1 potentized solutions (tenfold dilution). There is often more than one active ingredient in such solutions, and the labels also include infor- mation about possible side effects.
However, there are relatively few clinical tests regarding the effectiveness of homeopathic products. One of the most extensive databases for controlled clinical trials is the Cochrane Library, which has registered the results of 641,000 trials, 350 of which were done on homeopathic products. These trials typically investigated solutions with low potentization and more than one active substance.
The old debate about the efficacy of homeopathic drugs cannot be simply wrapped up with a yes or no answer. There are a few published analyses based on
Fig. 3.13 How do 100
particles decrease to zero in three steps? The principle of decimal potentization in a solution that contains 100 particles in the beginning. (Authors’ own work)
147
available clinical evidence, but they arrived at contradictory conclusions. Propo- nents and opponents of homeopathy can both pick their favorite studies and ignore the others. Without dwelling on details, the most recent summaries usually show that homeopathy has no more effect than a placebo. However, this is actually the wrong question. Homeopathy uses a large number of methods, often based on very different materials, and it only makes scientific sense to evaluate the individual products, not homeopathy as a whole.
The action-mechanism of homeopathic products is just as unclear as in the time of Hahnemann. Lack of knowledge about these mechanisms does not necessarily mean the absence of an effect. Many traditional drugs today have verified therapeutic effects, but understanding the mechanism is fragmentary at best. However, there is a serious ethical issue present: a product should only be officially declared to be a medicine if there is evidence to support this claim. Otherwise, citizens are misled.
To screen out the placebo effect as a possible source of error in judging thera- peutic efficacy, placebo-controlled clinical studies are necessary. The Cochrane Li- brary registered 150 studies utilizing this methodology, and some of them showed positive conclusions. This is a very small number, especially compared to the huge variety of homeopathic products sold, but in fact still larger than many of the op- ponents would believe.
Surprises also await a curious mind in the world of homeopathic remedies that have effects proven by placebo controlled, randomized, clinical double blind stud-
ies. Plant-derived products containing a mother tincture or a solution of D1 poten-
tization often feature detectable amounts of active ingredients. Chasteberry ( Vitex agnus-castus) is used in both homeopathic and conventional (allopathic) medicines. The two ‘different’ kinds of products contain just about the same amount of the same active ingredient (called casticin; Fig. 3.14 shows analysis results) and their thera- peutic recommendation is identical (managing the premenstrual stress syndrome).
In cases like this, the effects are not surprising at all and are fully explained by traditional medical theories based on receptor binding or the influence of en- zyme activity. Hahnemann’s intention was to lower doses in order to avoid side effects, but not all of today’s homeopathic products follow this principle, which is not illegal. The legal definition of homeopathy only specifies the method of prepa- ration, not the dilutions or concentrations. It would not be surprising if some of the products advertised as ‘homeopathic’ were shown to be effective even by the standards of conventional drugs, but it is unlikely that such therapies would follow Hahnemann’s principle of concentration ‘lowering’, and would most certainly have possible side effects as well.