Allium sativum (garlic) and candidiasis

Abstract

The aim of this research was to investigate the biological plausibility of the use of Allium sativum (garlic) as a treatment / preventative agent for vulvovaginal candidiasis (VVC, or vaginal thrush).

Recurrent VVC is a challenge to clinicians, and quality scientific evidence supporting mainstream management is scarce. Many women turn to the use of complementary and alternative medicine (CAM) when faced with this condition, which is even less well supported. A compound of garlic, allicin, has been found to be a potent anti-fungal agent in laboratory studies. Anecdotally some women use it both topically and orally to manage VVC. However, there were no human studies related to the use of garlic ingested for human fungal conditions, and difficulties with the known short half-life of allicin posed challenges for such research.

Since there was so little known about how garlic may be used in VVC, a number of preliminary studies were undertaken. These included:

• Testing Australian garlic products for allicin yield;

• A small mass spectrometry study to definitively ascertain whether allicin or its breakdown products may be detectable in body fluids after oral consumption;

• A clinician survey at the Australian and New Zealand Vulval Society annual meeting to establish clinicians’ knowledge of patients’ use of complementary therapies (including garlic), as well as the acceptability of complementary and alternative therapies to those managing women with candidiasis, and:

• A randomised controlled trial (RCT) to test the research question: In menstruating women, do daily oral garlic tablets taken two weeks before menstruation reduce vaginal colonisation of candida, compared with women taking placebo?

This was preceded by a pilot study designed to test and refine study methodology for the RCT.

The preliminary studies all provided background to, and informed, the RCT. The findings of the RCT did not support the use of oral garlic tablets taken for two weeks prior to menstruation to reduce vaginal colonisation of candida. Due to the lack of prior data informing sample size calculations, this study was most likely underpowered and conclusions of lack of vaginal anti-fungal effect of oral garlic tablets could not be confidently drawn. This study provides a starting point for future studies investigating the use of garlic in candidiasis using topical therapy or treatment for longer periods of time.