From what I've checked out, the claimed extra therapeutic properties
of Manuka honey are way overstated.
There is not enough evidence that methylglyoxal survives being eaten,
nor that it does any good inside the body. This is not an area in which
a lot of independently-funded research has been done, but although
there is as mall bit of evidence that in general honey can soothe a sore
throat,
there is not yet conclusive evidence to suggest that eating
shop-bought Manuka honey will be any more effective at this than
a cheaper alternative. Similarly, there hasn’t been robust conclusive
evidence to show it can be used to ease indigestion. So, although
some people will swear by its properties, this has not been backed
up by clinical trials.
Methylglyoxal Explained.
And it's a myth that only New Zealand produces "genuine" Manuka honey.
NZ has one species of
Leptospermum scoparium, its source, whereas
Australia has eighty species. And the plant originated in Australia before
the onset of the Miocene aridity 23 million years ago.
In a nutshell then, if you're paying a premium price for your NZ Manuka,
you're getting ripped off. Australian Manuka is $26.80/kg and NZ Manuka
is $40.00/kg (both prices @ Coles.) I note that some NZ producers are
retailing it for more than $100/kg!