12
NEWS
Is Zoe scientific?
Blood glucose monitors are unnecessary for
people without diabetes and could, in extreme cases,
fuel eating disorders, leading doctors have warned.
EDITORS NOTE: They use the words 'blood sugar', whereas the correct medical term is blood glucose.
Using continuous glucose monitors (CGMs) is
currently part of a personalised diet trend.
It's a trend promoted on social media and
spearheaded by companies including Zoe, the
costs of which start at around £300. You may have heard
of the recent Zoe shots being sold in M&S.
In the Zoe programme, participants log their food
intake and wear a continuous glucose monitor (CGM)
for two weeks to measure their blood sugar levels after
eating. In separate tests, they also have their responses
to fat, and their gut bacteria tested. Zoe says all of these
tests have helped it identify that even two healthy people
can have wildly different responses to the same food - for
example one person's blood glucose might spike and dip
more after eating carbohydrates than another person's. It
suggests this could guide individual food decisions.
However, other researchers argue that what, if
anything, those numbers mean - including bigger spikes
and dips in blood sugar within the non-diabetic range - is
still not properly understood. Dr Nicola Guess, a dietitian
and diabetes researcher at the University of Oxford, said
the majority of evidence linking high, and highly varied,
blood sugar to health problems is based on glucose
levels only seen in people with diabetes or prediabetes,
and that high blood sugar is a symptom, not directly a
cause, of diabetes. In people without diabetes, other
researchers have said, "the evidence base is nothing" for
understanding what the swings in blood sugar mean.
Young science
However, Zoe points to some evidence suggesting that
even before it reaches prediabetic or diabetic levels,
having higher blood sugar and big variations through
the day may be linked to some worse outcomes,
although most data is still from diabetic patients. It says
it is investigating gut bacteria and starting to see links
between gut microbes, diet and health.
Gut microbiome expert and colorectal surgeon at
Imperial College London, James Kinross, said while the
microbiome was very important, direct-to-consumer
testing was "problematic" because "this is such a young
science and there are many unanswered questions about
how the microbiome influences our health."
While some of Zoe's critics agree that CGMs could
potentially be a helpful tool for some people to motivate
them and change their diet, Dr Guess is concerned that
patients who use Zoe's products are cutting out foods
that are good for their health, because they seem to
spike their blood sugar. That in itself can lead to health
problems, and people who avoid carbohydrates can get a
temporarily "exaggerated glucose response" the next time
that they eat them - which she says is "perfectly normal,"
but that could potentially lead them to think they are
unable to tolerate carbs at all.
Dr Guess thinks that while a lot of Zoe's advice,
including around eating more whole foods and fewer
processed foods, is sensible, she believes this message is
'not compelling enough' to sell a £300 product.
Zoe has carried out a study to understand changes
caused by the programme, but it has not yet been
published.
www.zoe.com
To find out more, CLICK HERE.