Use of homeopathic preparations in experimental studies with healthy plants
Vera Majewsky, Sebastian Arlt, Devika Shah, Claudia Scherr, Tim Ja¨ger, Lucietta Betti, Grazia Trebbi, Leoni Bonamin, Peter Klocke and Stephan Baumgartner
Background: The last comprehensive review of experimental research on effects of
homeopathic treatments on plants was published in 1984, and lacked formal predefined
criteria to assess study quality. Since then several new studies with more advanced
methods have been published.
Objectives: To compile a review of the literature on basic research in homeopathy with
healthy plants with particular reference to studies investigating specific effects of homeopathic
remedies.
Methods: The literature search included English, French, German, Italian, Portuguese
and Spanish publications from 1920 to April 2009, using predefined selection criteria.
We included experiments with healthy whole plants, seeds, plant parts and cells. The outcomes
had to be measured by established procedures and statistically evaluated. We developed
a Manuscript Information Score (MIS) and included only publications which
provided enough information for proper interpretation (MIS$5). A formalised Study
Methods Evaluation Procedure (SMEP) was used to evaluate these studies, and the subgroup
of studies with adequate controls to identify specific effects.
Results: A total of 86 studies in 79 publications was identified, 43 studies included
statistics, 29 had MIS$5, and 15 studies investigated the specificity of homeopathic
preparations. Specific effects of decimal, centesimal and fifty millesimal potencies were
found including dilution levels far beyond the Avogadro number. In consecutive series
of potencies only some of the tested potencies showed effects. There were many individual
studies with diverse methods and very few reproduction trials.
Conclusions: Healthy plant models seem an useful approach to investigate basic research
questions about the specificity of homeopathic preparations. More investigations
with more advanced methods are recommended, especially in the sectors of potentisation
techniques, effective potency levels and conditions for reproducibility. Systematic
negative control experiments should become a routine procedure to control the stability
of the experimental systems. Homeopathy (2009) 98, 228–243.
Keywords: Review; Basic research; Homeopathy; Potentisation; Potentised dilutions