Is there Manuka Honey for Tea?

When Captain James Cook anchored in New Zealand after a long voyage across the Pacific Ocean he was probably dying for a cup-of-tea. It was already a popular drink in England by the 18th Century when he sailed from Whitby, and a pot of tea warming in a brown betty is still a familiar sight in Yorkshire. I remember people brewing it for hours to make a really strong cuppa, extracting enough tannin to cure a deer hide.

brew a cup of tea
my Brown Betty

The native people he encountered persuaded him to try making “tea” from the spiky leaves of a scraggy tree called Manuka in the Maori language, which his sailors named the tea tree (not to be confused with the Australian tea tree from which the famous oil is extracted). I too was missing Yorkshire tea on my latest visit to New Zealand and wanted to try Maori tea for myself. After brewing a bunch of dried tea tree leaves for an hour, the water turned faintly orange and developed a citrus fragrance. If appearances could be trusted, the “tea” was promising, but I hadn’t reckoned on a bitter assault of my palate by the terpenoids. Perhaps that experience hurried Cook home for his brown betty.

Tea tree (Manuka)
Tea tree (Manuka)

The tea tree might have remained in obscurity after Cook’s experiment because, apart from a seasonal show of white or pink blossoms, it is an ugly shrub. But sometimes there is great virtue and fortune hiding beneath an unattractive exterior. Someone noticed that nectar collected by honey bees from tea trees makes a highly distinctive kind of honey, which has become the most prized in the world. It looks like mud in a bottle or spread across a slice of toast, and most unappetizing compared to the clear and syrupy product in your grocery store. It tastes oily or earthy and lacks the intense sweetness that characterizes most honeys. It is so expensive that Tesco supermarkets in the UK lock it inside security boxes with alarms to thwart shoplifting. As caviar is to shrimp and vintage Burgundy is to a cheap Cab, manuka is to “garden” types of honey. It is gooey gold, as rare as the ore itself.

The reputation of Manuka honey forges past scientific and pecuniary caution like most other supposed health products, and goes even further. Some people speak of it reverently as if it is holy water. There is no doubt that it has antimicrobial activity, but regular honey has plenty from its peroxide and high sugar content from which it earned a reputation for wound healing even in ancient times. But it possesses other pharmacological properties that are unique and may make it superior for attacking bacteria and fungi. At least some medical professionals are convinced, because medical grade Manuka honey is used in wound dressings (it stings). But most people purchase it because they enjoy a spoonful as a treat, or to impress their guests with a luxury product going up in smoke after spreading it liberally over barbecued fish, or for treating a skin eruption or warding off a gastrointestinal devil. Manuka enjoys a high reputation because it is a product of the relatively clean New Zealand environment where it is harvested from hives deep in the bush far from crop spraying.

It is la crème de la crème for New Zealand beekeepers and their most valuable “crop” which they must guard against fake products because it is as vulnerable to fraud as a Vuitton or Gucci handbag.

Some cheaper Manuka honey mixes on NZ grocery shelves
Some cheaper Manuka honey mixes on NZ grocery shelves

As a natural product honey can never be guaranteed to be uniform or from a “pure” source. Bees have favorite food plants but a colony visits a range of flowers which vary during the flying season. Manuka is not in flower all the year round, and the properties of its nectar vary between seasons, sites and specimens. Every batch of honey is different, and therein is a dilemma for beekeepers preserving the quality and reputation of their product, and for customers who don’t want to be scammed.

Of course, you can be sure that honey marketed as Manuka at unbelievably cheap prices is unbelievable, but beyond that the customer has to look for an official sign of authenticity. There are plenty of brands labeled Manuka that honestly declare the fraction of the whole, but according to what I heard over 80% of that advertised as the genuine thing in Asia is adulterated with regular honey or syrup.

Beekeepers go to great lengths to protect their industry. One firm I know safeguards its product by bottling and labeling the entire harvest on its own premises. It is also licensed by the Unique Manuka Factor Honey Association which is a guarantor of quality after testing three compounds that account for some of the non-peroxide antimicrobial activity. Genuine products can be recognized by the UMF® label, and are rated for quality up to 20 (rarely available). UMF is the “official” standard, but customers are confused by ratings from an independent company which uses a different scale. In one airport shop I saw a kilogram bottle rated at MGO 800+ which is roughly equivalent to UMF 20. By the way, it cost NZ$800!

You might think the best test of Manuka in honey is the proportion of pollen grains from the tea tree. Unfortunately, the related Kanuka tree is also a favorite food plant of bees, but it has almost indistinguishable pollen and it doesn’t produce such a valuable crop of honey.

The UMF laboratory tests three compounds, including methylglyoxal (MGO) which is given the most credit for healing properties since it kills bacteria long after peroxide activity is degraded by catalase activity in human tissues. There little MGO in fresh honey, but it builds up during storage as the concentration of dihydroxyacetone (DHA) declines. DHA is the second compound tested for UMF. It is used elsewhere as a fake sun-tanning agent and I guess contributes to the browning of proteins in Manuka honey.

Beekeepers can’t sleep peacefully after their products pass the UMF test because MGO and DHA can be bought as pure compounds for adulterating “garden quality” honey. When I checked with an American chemical company from which I used to obtain lab supplies I could buy quantities of both compounds for a few hundred bucks, enough to fool labs of tons of honey. The industry is aware that a cat-and-mouse game may already be in play with fraudsters and is looking for more robust markers. Gas chromatography-mass spectrometry can generate a molecular fingerprint of honey samples which should be foolproof. The equipment tests far more markers than can easily be added and requires technical expertise, but the expense will eat into profits. The tea tree produces a wondrous honey, but it comes at a high cost and bitter taste.

Auckland Airport
Medicate with Manuka! (Auckland Int. Airport)

Posted in New Zealand

Next Post: Two Beekeepers in the New Zealand Bush

Frozen Eggs Perks as Policy

Ashton Carter announced the Pentagon will make a bigger commitment to family-building for people serving in the military. The package includes new benefits for maternity leave and child care, and even a pilot scheme for egg and sperm freezing. The news is less surprising since Facebook and Apple rolled out a policy of offering $20,000 perks to young employees for defraying the costs of egg banking, which amount to >$10,000 per cycle + annual storage fees.

The aim is to retain highly-trained staff from leaving early to start a family. Most women are aware that their biological clock starts to wind down from around age 30, long before the average age of menopause. Egg banking is portrayed as fertility insurance, but is it just a lottery?

egg freezing
Eggs come in from the cold

The first freezing trials with human eggs were far less successful than with embryos. Since they are delicate single cells, their survival is all-or-nothing, whereas embryos afford to lose one or two cells from the bunch. Fewer than half were surviving in the 1980s, and very few of them made babies with IVF. Even more alarming was the evidence that chilling damages apparatus in eggs on which the chromosomes “dance” during cell division, putting babies at risk of birth defects from the wrong number of chromosomes. Many labs besides our own tried to improve results, but the breakthrough came with vitrification, which turns cells into a glassy solid instead of ice. Masashige Kuwayama at the Kato Clinic in Japan perfected the method. It involves ultra-rapid cooling in a highly concentrated solution, similar in some respects and different in other ways to making smooth ice cream. Like home-made ice cream, vitrification is not a technically sophisticated process, but it demands expertise of the technician who, working under a microscope, mounts each egg in a minute droplet for plunging into liquid nitrogen. I wonder if a technique that depends so heavily on operator skill in an unregulated environment can produce consistent results across clinics.

Egg banking emancipates fertility preservation for women, whereas men have had sperm freezing since the 1950s. The original rationale for banking was to help young women preserve their fertility from the sterilizing effects of high-dose chemotherapy and radiation. It also helps women to have genetic children after a hysterectomy, although a surrogate must then be commissioned to carry the baby. Before egg banking there was embryo freezing, but that requires IVF and therefore a male partner, or ovarian tissue freezing, which we developed as an alternative technology and is still used for child patients. One of the great advantages of freezing eggs versus embryos is that there are fewer issues surrounding the disposal of surplus eggs because they carry less moral gravity.

Although egg banking has been a bright hope on the dark road through cancer treatment, it is now embraced by far greater numbers of healthy women. This is being encouraged by perks from employers and lauded by media reports and TV. As if that publicity was not enough, clinical providers are heavily invested in advertising. I am told that business is booming, and more and more fertility clinics want some of the action.

But pause to consider the “customer.” I think that word is more apt than either patient or client, because these women are seeking treatment for a non-medical condition (aging) and from for-profit clinics. More and more fertility clinics that started as private medical practices are becoming absorbed into big business. I suspect these entities are now looking less and less like a familiar medical environment and more and more like normal commercial operations.

And who is the typical customer? She is a professional or businesswoman in her 20s or early 30s who dares not step off the career ladder during her most fertile years, or perhaps she hasn’t found a Mr. Right yet. There are other reasons, but a common conflict is between biological imperatives and social pressures. Employers are slowly recognizing this dilemma, but the answer they provide (if any) is technology instead of a better deal for women’s careers. Consequently, the average age of motherhood is rising, and already passes 30 at the birth of the first child in several countries. Men are luckier, although fresh mutations are more common in older sperm.

What price would you pay for a child of your own? There’s the nub of it. Fertility treatment involving IVF is unaffordable by most couples on low incomes, and those who can afford egg banking to delay family-building are investing in uncertainty. As this is a new technology there are very few centers with enough data to provide a reliable estimate of the chances of pregnancy with banked eggs. A British authority (HFEA) reported that up to 2012 there were only 20 babies born from 160 treatment cycles, and the US registry (SART) announced 162 live births in 2014, a success rate of 1 in 5 cycles. We await updates.

Success can never be assured. Since the chances with one batch of eggs are unlikely to be high, multiple rounds of treatment (i.e., more eggs) are required, and preferably collected at very young adult ages. Can you think of another product costing as much with so little security? Would you buy a new car or boat from a dealer without a guarantee? Would you dare commit thousands of dollars to a lottery? The reason that people will spend so much on fertility services, even taking out large loans or remortgaging their home, is because having a baby is a life event. Nothing compares with it.

This cautious post may seem surprising from someone who spent his whole career in reproductive technology and biology. Egg freezing is, of course, a wonderful breakthrough which I welcome unreservedly for patients needing emergency fertility preservation, but to others I say let the buyer beware.

Posted in New Zealand