The anti-bacterial activity of Manuka honey is widely known, but new research by a German team has revealed that it is safe to eat and has its most potent ability to fight infection in the mouth, throat and stomach.
Professor Thomas Henle of the Institute of Food Chemisty, Technical University of Dresden, has undertaken new research into dietary methylglyoxal, the compound he identified in 2006 as responsible for manuka honey's antibacterial properties.
Speaking at the University of Waikato (Monday, 20 February), Professor Henle said dietary methylglyoxal in manuka honey was stable under the conditions of the mouth, throat and stomach where it can kill bugs that cause infection.
The Dresden research team, which examined the possible health risks of consumption of naturally-occurring methylglyoxal, found that when it reached the small and large intestine, it was rapidly degraded into lactic acid.
"The findings show unambiguously that methylglyoxal in manuka honey is not absorbed into the body and does not pose a dietary risk for consumers," Professor Henle said.
"This is good news for all manufacturers of manuka honey and for consumers. Manuka honey is safe to eat - people can eat as much as they like whenever they like."
The Dresden research focused on "glycation reactions", also known as "non-enzymatic browning", responsible for the quality of heated and stored foods, including colour and flavour.
These complex series of reactions in which proteins react with carboydrates lead to a large number of secondary products, one of which is methylglyoxal in manuka honey.
Some dietary glycation compounds in foods may pose a health risk. Others, such as the so-called melanoidins in coffee, may also exert beneficial effects by inhibition of tumour-related enzymes.
Until now the chemistry behind honey-specific glycation reactions and the resulting consequences for manufacturers and consumers was widely unknown.
Many studies show that manuka honey high in methylglyoxal may represent an effective cure against Helicobacter pylori, a bacterial infection of the stomach which may affect up to half the world's population.
H. pylori is frequently without symptoms but under certain conditions causes chronic gastritis and gastric ulcers. It is also linked to development of duodenal ulcers and stomach cancer.
Professor Henle said that antibiotics often fail to treat H. pylori effectively, but his studies show that manuka honey with high levels of methylglyoxal is stable in the stomach and, therefore, may offer a promising cure and improved gastrointestinal health.
Professor Henle's 24-year research career has focused on reactions during food processing, particularly protein and carbohydrate modifications. He is the author of more than 125 papers in peer-reviewed journals, nine patent applications and has appeared in at least 180 other publications.
He holds many prestigious posts, including President of the German Society of Food Chemistry, Editor-in-Chief of major food chemistry journals and member of the Scientific Advisory Board of the Federal Institute of Risk Assessment.
Professor Henle's visit to New Zealand, his first, has been sponsored by Manuka Health New Zealand in association with the University of Waikato and the University of Auckland.
Manuka Health New Zealand was formed in 2006 after Professor Henle identified methylglyoxal as the compound responsible for manuka honey's anti-bacterial activity. The company has led the way in developing an accurate testing regime to measure methylglyoxal levels in manuka honey.
It is the only company worldwide to market manuka honey with certified levels of methylglyoxal. Its extraction facility at Te Awamutu has ISO 17025 certification and accreditation by International Accreditation New Zealand (IAANZ). Manuka Health's test method has been cross-validated with the method at Dresden Technical University's Institute of Food Chemistry.
Join Voxy on Google+.