A review published in International Journal of Microbiology, titled Antibacterial Potency of Honey, has revealed that multiple studies support the hypothesis that dark-coloured honeys (such as Manuka, heather or chestnut honey) have higher antibacterial properties than lighter-coloured honeys (like clover, acacia or rapeseed honey).
Dr Najla Albaridi, from the Division of Nutrition and Food Sciences at Princess Nourah Bint Abdulrahman University in Saudi Arabia, looked at 80 papers to review current knowledge on the antibacterial activity of different honeys, and their use in the treatment of disease. As well as analysing different coloured honeys, she also investigated what other factors affect antibacterial potency in honey.
Albaridi concluded that while high viscosity (high sugar concentration and low water content) and high acidity contribute to unfavourable conditions for bacterial growth in general, a major distinction can be found in the main antibacterial agent. The author suggests that honey can be classified into two main groups: those whose antibacterial activity is hydrogen-peroxide dependent (honeys of American, European, and some Asian origin) and those whose activity depends on the presence of methylglyoxal (like New Zealand Manuka honey).
Further variation was found in phenolic content; compounds that were recognized as important antibacterial components of honey as early as the 1990s. Season, geographical location and botanical origin (blossom source) were all identified as factors influencing the phenolic acid and flavonoid content of different honeys.
A number of studies showed that honey exhibits a broad-spectrum of antibacterial activity against a wide range of bacteria, including antibiotic-resistant ones like MRSA. More research is needed to determine what concentration is effective, but this review lends support to the theory that honey could be a vital tool in the fight against antibiotic resistance, as well as providing encouragement for further scientific research into other nature-based, traditional remedies.
This blog post is distributed under the Creative Commons Attribution License (CC-BY). Illustration by David Jury.