Saturday, July 7, 2012

From your Kiwi Correspondent Part VI

Over the last half year, I’ve been scrutinizing health-specific differences between Kiwi and American societies. This has been a bit of a brain-buster and I don’t feel that, to borrow a Kiwi phrase, I’ve got it “properly done and dusted.” Just when I was getting discouraged, however, I found something about health in New Zealand that’s clearly superior to back home – the Kiwis have healthier honey!

Specifically, I’m referring to manuka honey produced by bees collecting nectar from the manuka bush (Leptospermum scoparium). This bush, which is quite plentiful throughout New Zealand, is rather ordinary looking – something like what you might expect if you crossed an azalea with rosemary. But, similar to the mold of penicillin, the manuka bush has surprising properties hidden behind its mundane appearance. Before arriving in New Zealand, I’d heard about manuka honey, but (being naturally skeptical about “natural” treatments with unnaturally ambitious claims) I’d quickly set it aside in the “I’ll research that later” bucket. It wasn’t until a couple parents of pediatric burn patients asked me whether I recommended manuka honey as a topical treatment that I actually began that research.

When I did, I first confirmed what I already knew – that for centuries, people have utilized all types of honey for therapeutic purposes. In fact, before antibiotics were developed, honey was a common dressing for infected or non-healing wounds. But, and this was news to me, starting around about 170 years ago when the European honeybee was introduced to New Zealand (interestingly, the native New Zealand bees did not forage from the manuka bush), Kiwis began to notice that honey made from the nectar of the manuka was distinct. First of all, it was darker and richer in color and second it did not taste very good – which is why many combs of manuka honey were tossed away as useless.

Later, folks noticed a third difference – manuka honey used for medicinal purposes seemed to work better than other honey varieties. So, starting several decades ago, researchers began to investigate what makes manuka honey different. In the early 1980’s, Peter C. Molan, a biochemist at The University of Waikato in New Zealand, conducted a simple yet elegant experiment that illustrated the antibacterial activity of manuka honey. He added the enzyme catalase (present in human saliva, blood, and other tissues) to two different types of honey – traditional clover honey and manuka honey. In doing so, he disabled the hydrogen peroxide in both honeys – an important step, as up to that point, scientists credited hydrogen peroxide alone with giving honey its antibacterial properties. In Molan’s experiment, the peroxide was nullified and (as predicted) the clover honey stopped killing bacteria while the manuka honey’s antibacterial activity was unaffected.

This discovery sent Molan and others on a 25-year quest to discover the biochemical ingredient in manuka that provides this non-peroxidase antiseptic action. Ultimately, a team from Germany stumbled across the answer – a substance called methylglyoxal. Meanwhile, back in New Zealand, Molan established the world’s first Honey Research Unit and unearthed many other honey secrets. Fast-forward to 2012, and Molan has compiled compelling evidence that honey is a lot more than Winnie the Pooh’s cure for a rumbly tumbly. “The only reason for being a bee,” Pooh once said, “is to make honey, and the only reason for making honey is so I can eat it.” Molan would disagree. Based on work from his laboratory and others, Molan ascribes the following therapeutic attributes to honey… (Below is a summary of published and unpublished work.)

• Honey stimulates white blood cells’ immune response
• Honey has pre-emptive antioxidant activity – it can stop potentially cell-damaging free radicals from forming.
• Honey removes pus and dead tissue from wounds.
• Manuka honey has these benefits as well unique antibacterial activity that is more persistent in its interaction with wound bacteria.

Additional purveyance of the literature demonstrates in vitro evidence of manuka honey’s unique action against methicillin-resistant staph aureus (MRSA). A study out of Wales by Jenkins and Cooper (Journal of Antimicrobial Chemotherapy, December 2011) found that not only does manuka honey effectively kill MRSA at low concentrations (6% weight/volume) on agar but also that it down regulates the gene (mecR1) thought to be responsible for the germ’s resistant properties. Furthermore, the investigators found in microarray analysis that a combination therapy of oxacillin and sub-inhibitory concentrations of manuka honey showed significant synergistic effects against MRSA. This, then, raises the possibility that cephalosporins combined with topical manuka honey might be a viable strategy for treating skin MRSA infections.

So, if you haven’t already, you are likely to hear more about the medicinal uses of honey, in particular, manuka honey. The FDA has now approved manuka honey (in wound dressings) and there surely are marketers out there salivating over taglines. But before you put manuka on the honey-do list, there are some not-so-sweet caveats and they start with the cost. At one Bay Area natural food store, one would need to spend $23.98 for 8.75 ounces of high-end manuka honey. And, such honey is only a tad cheaper here in the source land. Then, there is the variability in therapeutic activity. Honeybees haven’t yet agreed to be standardized and the potency of their honey differs on a batch-to-batch basis. There are rating systems in use, but they are not fully reliable.

Still, honey is good stuff and may be useful from head (an proven treatment for hair loss) to toe (foot ulcer dressings). And while it’s clear that manuka honey is special honey, the question is, at this point, is manuka worth the money?

To find out whether manuka could live up to expectations, I visited Dr. Peter C. Molan, the founder of the Honey Research Unit at the University of Waikato and the world’s foremost expert on the medicinal qualities of honey.

I sat with Molan in his 60’s era lab, as graduate students finished up experiments around us. Molan is an oak of a man – tall and sturdy with sharp blue eyes – but warm and generous with his time and thoughts.

“Honey took over my life,” he explained, while his students worked on separating milk caseins. “I used to do other things; it all started out as a hobby. Now I’ve been studying it for forty years.” And in those forty years, Molan has become influential and ardent in his beliefs about the medicinal benefits of honey.

Molan’s passion is based both on science and personal experience. Scientifically, Molan points to the molecular makeup and antibacterial activity of all honey as well as the specific non-peroxidase properties of manuka honey. He also explains the physiologic benefits of manuka honey as anti-inflammatory and anti-oxidant  – including the inhibition of phagocytosis in wounds, especially burns. Personally, Molan calls upon the examples of friends, family, and strangers to whom he’s recommended honey over the years and the stories they’ve brought back to him. For example, Molan’s wife used manuka honey to treat a severe scald burn and one of his friends has successfully tempered his sour stomach by having a spoonful of honey every night before his wine. 

But, there is melancholy in Molan when he speaks about manuka – he laments the reluctance of the medical world to buy into therapeutic honey. “Evidence based medicine – everyone says they support it – but in reality they only buy into something they have a rationale for. ” Even in New Zealand, manuka honey is not considered a frontline treatment for wounds by the district health boards – due primarily to cost considerations (the exception being Molan’s home district of Waikato.) Another frustration for Molan is the commercialization of the manuka honey market – in particular the manipulation of rating systems and widespread disingenuous marketing. For example, says Molan, there is now honey being sold as “Active Manuka Honey,” but the “activity” the seller is referring to is the antibacterial activity (due to hydrogen peroxide) that is present in all honey, not the non-peroxide type of antibacterial activity that is unique to manuka honey.

When I ask Molan the critical question – is manuka honey worth the money – he hesitates for a moment. “If you look at the total cost,” he responds, “which means taking into account the time to healing, and thus the total number of dressings needed and the cost of the staff time and facilities – there is a huge saving to be made by using manuka honey if it is used in a ‘best practice’ method.”

Molan is certainly the world expert on this topic, but he also has a bit of an insular view as well as a potential conflict of interest (which he readily admits) as the owner of patents on honey, including on a manuka honey impregnated wound dressing. So, he may not be completely seeing the comb for the bees.

Here then, is the bottom line on what I have concluded about honey, and in particular manuka honey.

*Honey, any honey, might be beneficial for simple sunburns, superficial burns, heartburn-like sour stomach, and cold symptoms.

*The level of scientific proof on these benefits is mixed, although the risk of use is probably pretty low – although it is still prudent to follow the advice of the American Academy of Pediatrics and avoid feeding honey (any raw honey) to children under the age of one due to the small risk of contracting botulism.

*For open wounds and severe burns, manuka honey is almost certainly superior to regular honey – but if patients are buying it over-the-counter, it will be both expensive and fraught with the potential for misinterpretation of activity. Also, be aware, as a Kiwi plastic surgeon told me, that honey applied to open wounds may sting quite a bit.

*Gamma irradiated manuka wound dressings hold promise, especially for pressure wounds and complicated burns that are not healing with standard treatment and dressings (like hydrocolloid or silver-impregnated dressings.) In this regard, the American market is still evolving.

So, there you go, as crystal clear as a manuka mud bath. Indeed, if the therapeutic use of honey interests you (or your patients), it appears you will just have to stay tuned to see how both the science and the business sort themselves out. Until then, as Pooh says “Oh yes, I'm rumbly in my tumbly. Time for something sweet.”