Mānuka honey: medical marvel or expensive snake oil?
If you want to pay over $100 for about a cup worth of honey, mānuka is the one for you.
Mānuka honey is earthier, richer, and more viscous than many other honeys, and it's also been much better marketed. Celebrities from actors to sports people are seemingly unable to get enough of the stuff, and are probably the people best placed to pay $50-$1500 for 250g.
Dr Nural Cokcetin, a microbiologist from the University of Technology Sydney who specialises in honey, says regular honey is also chock full of antimicrobial compounds and has been used as a wound dressing for thousands of years.
"For the past 15 or so years, I’ve been researching the medicinal properties of honey," Cokcetin told Cosmos.
"As a microbiologist I was interested in finding new ways to deal with infections caused by bacteria that are resistant to antibiotics, and honey has been one of those medicines that we’ve used throughout history."
Honey isn't just another form of sugar. This bee regurgitation (sorry) is made from the nectar of flowing plants and would traditionally be saved inside honeycomb for the bees to eat in times of scarcity.
In the process of being made into honey, the nectar is ingested by the bee and enzymes inside the bee mix in with it. The nectar goes through a number of bees before being placed in the honeycomb and fanned by the bees’ wings to get any extra water out.
All these processes make honey surprisingly good for certain health applications.
"For a long time, it was used to treat things like wounds and skin conditions," Cokcetin says.
"People knew that wounds would fester, and they would turn rotten – things were getting infected, and we didn't have treatment options. Honey was used to treat and dress wounds.
"It was particularly heavily recorded in the ancient Egyptian script – they had something like 900 prescriptions, and over 500 of those involved honey to some degree. A lot of them were to dress wounds."
Honey's impressive wound dressing properties are due to a few factors.
Firstly, honey has low moisture and high sugar. Some sugar is good for microbes, but lots of sugar can be used as a preservative that removes bacteria; honey works the same way. Low moisture is also helpful for this as most microbes need water to thrive.
"Everyone often thinks of honey it's just a generic thing – all honey is the same – but it's really complex. It's got over 200 different components and many of those have anti-microbial properties themselves," says Cokcetin.
On top of that, honey is quite acidic, and in some cases there's an enzyme in it that – when combined with water (or wound moisture) – can produce small amounts of hydrogen peroxide, which works like a diluted bleach.
Regular honey seems pretty good, but according to Cokcetin does admit there are a few things about the mānuka flower that might justify mānuka honey's price tag.
"Mānuka honey has a lot of really good scientific research behind it and what makes it really special comes back to the anti-microbial activity," she says.
Get an update of science stories delivered straight to your inbox.
"What makes mānuka special is it has an added level of anti-microbial activity. And this comes directly from the plant source."
Mānuka trees – in Australia they are sometimes called jelly bush or goo bush – are a type of tea tree of the genus Leptospermum.
These Leptospermum trees have a compound called methylglyoxal (MGO), a substance that occurs naturally in many foods, including coffee, soy sauce and roast turkey. Mānuka honey has quite a lot of MGO, and this compound seems to have antimicrobial activity separate from the hydrogen peroxide or other compounds in normal honey.
But honey's – even mānuka's – antibacterial activity works best on the skin. As you eat and digest, a lot of these enzymes and compounds break down.
It might help for a sore throat, but for anything further down there's not a lot of evidence of its antibacterial activity working.
"I always say, if you can afford to eat mānuka honey and if you like the taste of it – great," says Cokcetin.
"But in terms of eating, it probably isn't having that much more of an effect than any other honey."
New Zealand has the mānuka honey process down to an art. They have one species of mānuka called Leptospermum scoparium, of which there are large plantations to produce what's called ‘monofloral’ honey. This honey is produced using nectar from mostly L. scoparium plants.
This is in contrast to multifloral honey, created when bees forage over a wider area that includes mānuka nectar in it.
Mānuka honey is regularly tested to ensure it has the signature chemicals and DNA that ‘authenticate’ it as mānuka honey. Most of the honey is also labelled with the amount of MGO as a measure of its potential anti-microbial properties.
Australia has over 80 species of Leptospermum, and some of these species are three or four times more active than the New Zealand version. However, Australia's Leptospermum is a little more ad hoc.
"In Australia, it's a little bit harder," says Cokcetin.
"A lot of our beekeepers rely on access to national parks and public lands. These are forests with gum trees, so we’ll have Leptospermum bushes, but we’ll also have lots of different gum trees as well. But those also have some kinds of activities."
Recently there's been some controversy over using the term ‘mānuka honey’ for Australia's honey production.
In the last few years, the New Zealand's Manuka Honey Appellation Society has been trying to trademark the term. This would mean that Australian mānuka honey would no longer be able to be called mānuka. This is similar to Australian sparkling wine not being allowed to use the word "champagne", even though it's made by the same method.
However, New Zealand was not successful in Australia, Britain or the US, so (for now at least) both Australia and New Zealand are free to use and market under ‘mānuka’. By the way – if you want to know how to say ‘mānuka’ properly, you can listen here.
Originally published by Cosmos as Mānuka honey: medical marvel or expensive snake oil?
Jacinta Bowler is a science journalist at Cosmos. They have an undergraduate degree in genetics and journalism from the University of Queensland and have been published in the Best Australian Science Writing 2022.
There's never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.
Let's talk honey What's different about mānuka honey? Trademarks to tea tree