Case Studies & Clinical Trials
There have been no large-scale, robust clinical trials for medical-grade honeys as wound treatments, despite it being registered as a medical device and being available for use as prep-repared wound dressings or in tubes as pure honey to be applied to dressings or directly to wounds. Medical-grade manuka honey has been recently adopted by some primary care trusts in the UK and is now part of the British National Formulary; despite this, use remains low. Clinical trials into the safety of consuming UMF 20+ manuka honey have been undertaken with healthy individuals aged 42–64 years, but focused only on the safety of manuka honey following consumption. The trials concluded that this honey was indeed safe for consumption and did not cause any side effects; however, it did not have any effect, beneficial or otherwise, on the microbial composition of the GI tract. Double-blind, randomized trials have also tested the efficacy of honey and manuka honey against bacterial infection in patients with radiation-induced oral mucositis. The honeys were given orally with syrup used as a nonhoney control. Initially throat swabs were taken to determine the presence or absence of infection, and patients were advised to swallow the honey or syrup treatment slowly. Following completion of the treatment, throat swabs were taken again and compared with the original swab. The study showed that both honey and syrup were effective, but no better than each other, and that manuka honey was not effective at reducing bacterial infections. There have subsequently been no follow-up studies and it is likely that, despite the significant reduction in the number of patients without infection following honey and syrup treatment, it is unlikely that either treatment would have been in contact with the site of infection for long enough to either kill or prevent adhesion of potential pathogens to the host. It is known, for example, that to remove established biofilms in vitro, honey must be applied to the biofilm for at least 2 h and other factors may have predisposed patients to infection during the course of this study.
Randomized controlled clinical trials focusing specifically on wound infection have demonstrated that manuka honey applied to patients with infected wounds resulted in a 70% reduction in the recovery of MRSA and a 33% reduction in the recovery of P. aeruginosa following 4 weeks of treatment. However, a study of 368 patients with venous leg ulcers, where 187 were treated with honey and 181 were treated with conventional care, demonstrated that there was in fact no statistically significant difference between the two treatment groups, and, in fact, honey was not only more expensive, but was associated with a higher incidence of adverse effects. Data from the Cochrane Database has found that there are little robust, reproducible data suggesting that honey is any more efficacious than other topical wound treatments. The review concluded that largely due to insufficient evidence and poor quality trail reports, there is a lack of evidence to guide clinical practice. It is therefore evident that medical grade honeys need to continue to undergo robust, appropriate clinical trials if they are to find a place in clinical practice as a prophylactic or treatment for wound infection.
Future Microbiol. 2013;8(11):1419-1429. © 2013 Future Medicine Ltd.