Skip Navigation LinksHome > September 20, 2012 - Volume 34, - Issue 9B, > Screened & Examined: The Sweet Medicinal Effects of Manuka H...
Emergency Medicine News:
doi: 10.1097/01.EEM.0000421441.70198.cc
Screened & Examined

Screened & Examined: The Sweet Medicinal Effects of Manuka Honey

Ballard, Dustin MD

Free Access
Collapse Box

Author Information

Dr. Ballard is an associate emergency physician at Kaiser-Permanente in San Rafael, CA, and the chair of the CREST ED Research Network. His writing credits include co-authorship with Angela Ballard of the award-winning travel narrative A Blistered Kind of Love: One Couple's Trial by Trail (Mountaineers Books, 2003) and authorship of The Bullet's Yaw (IUniverse, 2007). Dr. Ballard writes a biweekly-medical column for the Marin Independent Journal, which he posts on his blog: http://incisionanddrainage.blogspot.com.

I've been scrutinizing health-specific differences between the Kiwi and American societies over the past six months. This has been a bit of a brain-buster, and I don't feel, to borrow a Kiwi phrase, that 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!

Image...
Image...
Image Tools

I'm referring to the manuka honey produced by bees collecting nectar from the manuka bush (Leptospermum scoparium). This bush, which is in 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. I heard about manuka honey before arriving in New Zealand, 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.

I first confirmed what I already knew, that for centuries people have utilized all types of honey for therapeutic purposes. In fact, honey was a common dressing for infected or non-healing wounds before antibiotics were developed. 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. It was darker and richer in color, and it did not taste very good, which is why many combs of manuka honey were tossed away as useless.

Folks later noticed a third difference. Manuka honey used for medicinal purposes seemed to work better than other honey varieties. Starting several decades ago, researchers began to investigate what makes manuka honey different. Peter C. Molan, PhD, a biochemist at the University of Waikato in New Zealand, conducted a simple yet elegant experiment in the early 1980s 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. Adding catalase disabled the hydrogen peroxide in both honeys, an important step because scientists had until then credited hydrogen peroxide alone with giving honey its antibacterial properties. Dr. Molan's experiment nullified the peroxide, and (as predicted) the clover honey stopped killing bacteria while the manuka honey's antibacterial activity was unaffected.

This discovery sent Dr. 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, Dr. Molan established the world's first Honey Research Unit, and unearthed many other honey secrets. Fast-forward to 2012, and Dr. 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.” Dr. Molan would disagree. He ascribes therapeutic attributes to honey based on work from his laboratory and others. (This is a summary of published and unpublished work.)

New Zealands manuka ...
New Zealands manuka ...
Image Tools

* 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 as 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 Staphylococcus aureus (MRSA). A study from Wales by Jenkins and Cooper found that manuka honey not only effectively kills MRSA at low concentrations (6% weight/volume) on agar, but that it also down-regulates the gene (mecR1) thought to be responsible for the germ's resistant properties. (J Antimicrob Chemother 2012;67[6]:140.) The investigators also found in microarray analysis that a combination therapy of oxacillin and subinhibitory concentrations of manuka honey showed significant synergistic effects against MRSA. This raises the possibility that cephalosporins combined with topical manuka honey might be a viable strategy for treating MRSA skin infections.

You are likely to hear more about the medicinal uses of honey, manuka honey in particular. The Food & Drug Administration has now approved manuka honey (in wound dressings), and surely marketers out there are 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. One Bay Area natural food store charges $23.98 for 8.75 ounces of high-end manuka honey. Honey is only a tad cheaper in the source land. The honey also shows variability in therapeutic activity. Honeybees have not 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). It's clear that manuka honey is special honey, but is manuka worth the money?

I talked with Dr. Molan in his 1960s-era lab to find out whether manuka could live up to expectations. He is an oak of a man, tall and sturdy with sharp blue eyes, and he was 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 40 years.” He has become influential and ardent in his beliefs about the medicinal benefits of honey over those 40 years.

Dr. Molan's passion is based on science and personal experience. He pointed to the molecular makeup and antibacterial activity of all honey as well as the specific non-peroxidase properties of manuka honey. He also explained the physiologic benefits of manuka honey as an anti-inflammatory and antioxidant, including the inhibition of phagocytosis in wounds, especially burns. Dr. Molan recounted the friends, family, and strangers to whom he's recommended honey over the years and the stories they brought back to him. His 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 a melancholy is palpable in Dr. 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.” Manuka honey is not considered a frontline treatment for wounds by the district health boards, even in New Zealand, primarily because of cost considerations (the exception being Dr. Dr. Molan's home district of Waikato.) Another frustration for the honey researcher is the commercialization of the manuka honey market, in particular the manipulation of rating systems and widespread disingenuous marketing. Dr. Molan said honey is now being sold as “Active Manuka Honey,” but the “activity” to which the seller refers is the antibacterial activity (because of hydrogen peroxide) that is present in all honey, not the non-peroxide type of antibacterial activity that is unique to manuka honey.

I asked Dr. Molan the critical question — is manuka honey worth the money? — and he hesitated. “If you look at the total cost,” he responded, “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.”

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

I have concluded that honey, particularly manuka 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. It is still prudent, however, to follow the advice of the American Academy of Pediatrics to avoid feeding honey (any raw honey) to children under 12 months because of the small risk of contracting botulism.

Manuka honey is almost certainly superior to regular honey for open wounds and severe burns, but if patients are buying it over-the-counter, it will be 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.) The American market for this 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 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.”

© 2012 Lippincott Williams & Wilkins, Inc.

Login

Article Tools

Images

Share