Introduction: The Italian Medieval doctor Thaddeus Florentinus (AD 1210-1295) claimed that herbs could cure or relieve various symptoms such as obstipation, melancholia and nervousness. Additionally, certain herbs were proposed to be able to predict the weather and induce the vision of elves. Therefore, the aim of this study was to investigate whether herbs could have medical properties as claimed.
Methods: A randomized controlled trial with three arms was conducted: 1) Gin with St. John's wort, 2) Gin with angelica and 3) Gin with sweet woodruff. Participants were 21 anesthesia registrars. The primary outcome was visual induction of elves (yes/no) whereas secondary outcomes included melancholia (VAS 0-100), nervousness (VAS 0-100), weather prediction capabilities (yes/no) obstipation (Bristol Stool Chart 1-7) and others. Baseline recordings were obtained and hourly registrations of outcomes were undertaken. Confounding factors such as alcohol intoxication and vivid imagination was controlled by the means of alcohol breathalyzers and assessment of cerebral oxygenation by near infrared spectroscopy.
Rresults: The vision of elves was induced in 10 out of 21 participants (48.6%) and was associated with male sex (p = 0.01), young age (p = 0.03) and increase in cerebral oxygenation (p = 0.04) but not with sweet woodruff (p = 0.83) or alcohol intoxication (p = 0.26). Participants were not capable of predicting the weather forecast (p = 0.55). Melancholia and nervousness were not relieved by St. John's wort, and obstipation could not be relieved by the intake of angelica.
Conclusion: Sweet woodruff, St. John's wort and angelica were unable to relieve relevant Christmas symptoms as proposed by a medieval doctor. Alcohol ingestion might have influenced results, and data should be interpreted in the light of these precautions.
Funding: none.
Trial registration: not applicable.