After > 200 years of existence, homeopathy still remains unproven – in fact, most rational thinkers would call it disproven. Today only homeopaths doubt this statement; they work hard to find a water-tight proof that might show the doubters to be wrong.
What is better suited for this purpose than a few rigorous animal experiments?
Engystol® is a popular homeopathic product promoted as an anti-viral agent manufactured by Heel GmbH, Baden-Baden, Germany. In several in vivo and in vitro studies, it apparently affected an immune response. This new study was to “evaluate the innate and adaptive immuno-modulatory effects of oral Engystol® (1 or 10 tablets/L water consumed), prior to and post antigenic challenge in a mouse model with a well-characterized and clinically measureable immune system.”
The investigators first evaluated the murine immune response when oral Engystol® was given alone for 28 days. to mice. The animals were then challenged with an antigen-specific H5N1 HA vaccine while on Engystol® for an additional 33 days. Serum and supernatants from cultured splenic lymphocytes were collected and screened with a 32-cytokine panel. Serum vaccine epitope-specific IgG titers plus T cell and B cell phenotypes from splenic tissue were also evaluated.
The results showed that Engystol® alone did not alter immunity. However, upon vaccine challenge, Engystol® decreased CD4+/CD8+ ratios, altered select cytokines/chemokines, and anti-H5N1 HA IgG titers were increased in the group of mice receiving 10 tablet/L.
The authors concluded that “these data suggest that Engystol® can modulate immunity upon antigenic challenge.”
Engystol is being advertised as “a homeopathic preparation which has been scientifically proven to significantly reduce the duration and severity of symptoms during an acute viral infection and help protect from subsequent infections.” I was unable find good evidence for this claim and therefore have to assume that it is bogus. The only human trial I was able to locate was this one:
To compare the effects of a complex homeopathic preparation (Engystol; Heel GmbH, Baden-Baden, Germany) with those of conventional therapies with antihistamines, antitussives, and nonsteroidal antiinflammatory drugs on upper respiratory symptoms of the common cold in a setting closely related to everyday clinical practice.
Nonrandomized, observational study over a treatment period of maximally two weeks.
Eighty-five general and homeopathic practices in Germany.
Three hundred ninety-seven patients with upper respiratory symptoms of the common cold.
Engystol-based therapy or common over-the-counter treatments for the common cold. Patients receiving this homeopathic treatment were allowed other short-term medications, but long-term use of analgesics, antibiotics, and antiinflammatory agents was not permitted. Patients were allowed nonpharmacological therapies such as vitamins, thermotherapies, and others.
MAIN OUTCOME MEASURES:
The effects of treatment were evaluated on the variables fatigue, sensation of illness, chill/tremor, aching joints, overall severity of illness, sum of all clinical variables, temperature, and time to symptomatic improvement.
Both treatment regimens provided significant symptomatic relief, and this homeopathic treatment was noninferior in a noninferiority analysis. Significantly more patients (P < .05) using Engystol-based therapy reported improvement within 3 days (77.1% vs 61.7% for the control group). No adverse events were reported in any of the treatment groups.
This homeopathic treatment may be a useful component of an integrated symptomatic therapy for the common cold in patients and practitioners choosing an integrative approach to medical care.
Let me comment on the human study first. It is an excellent example of the bias that can be introduced by non-randomization. The patients in the homeopathic group obviously were those who chose to be treated homeopathically. Consequently they had high expectations in this therapy. Consequently they reported better results than the control group. In other words the reported outcomes have nothing to do with the homeopathic remedy.
But what about the animal study? Animals, we hear so often, do not exhibit a placebo response. Does that render this investigation any more reliable?
The answer, I am afraid is no.
The animal study in question had no control group at all. Therefore a myriad of factors could have caused the observed result. This study is very far from a poof of homeopathy!
But even if the findings of the two studies had not been the result of bias and confounding, I would be more than cautious about viewing them as anything near conclusive. The reason lies in the nature of this particular homeopathic remedy.
Engystol® contains Vincetoxicum hirundinaria (D6), Vincetoxicum hirundinaria (D10), Vincetoxicum hirundinaria (D30), sulphur (D4) and sulphur (D10). In other words, it is one of those combination remedies which are not sufficiently dilute to be devoid of active molecules. Sulphur D4, for instance, means that the remedy contains one part of sulphur in 10 000 parts of diluent. It is conceivable, even likely that such a concentration might affect certain immune parameters, I think.
And my conclusion from all this?
The proof of homeopathy – if it ever came – would need to be based on investigations that are more rigorous than these two rather pathetic studies.