16 November 2019 | New Scientist | 17THE slogan “Shop with your DNA”
is emblazoned above customers’
heads in a striking store in central
London. One wall is lined with
rows of multicoloured cubicles
that contain printer-like DNA
testing devices.
I’m stood in DNANudge,
which opened last week. It claims
to help people make better food
shopping choices based on their
genes and lifestyle factors such
as physical activity, although the
effectiveness of personalised
diets based on genetic testing is
far from proven.
DNA swabs are being analysed
in the store. Customers rub the
inside of their cheeks with a
cotton bud. This is then placed in
a small device for analysis, which
takes around an hour, testing for
genes associated with caffeine
metabolism and a predisposition
for hypertension, high cholesterol
and type 2 diabetes.
The information is turned into a
personal profile that recommends
limits of dietary components,
including salt, fat and sugar. For
£80, customers can then purchase
a wristband for scanning barcodes
on supermarket packets. It
flashes red or green depending
on whether a food item “fits” a
person’s dietary intake profile.
For example, if someone is
predisposed to having high blood
pressure, the wristband may flash
red for a choice that is high in salt.
A connected smartphone app
would then suggest alternatives
in the same food category.
DNANudge has a database of items
found in most UK supermarkets
to make this function work.
I tested a shop assistant’s
wristband on some cereal and
it gave her the green light for
chocolate chip Weetabix. It feels
strange to have such a simple
piece of tech telling you what
you should and shouldn’t eat – it
seems a bit like having a traffic
light for a diet coach.
“The best diet is the diet you
don’t know you’re having,” says
DNANudge CEO Chris Toumazou.
“Mindless overeating becomes
mindless healthy overeating.”
But can your DNA help you
do this? To date, there is little
research to suggest that eating
based on your genes conveys
any significant benefits.
Nita Forouhi at the University
of Cambridge co-authored a 2018
study involving 21,900 people that
found that the link between dietand developing type 2 diabetes
wasn’t affected by genetic risk
factors for type 2 diabetes, insulin
resistance or high BMI. “This
suggests the same dietary
recommendations are relevant
for type 2 diabetes regardless
of differences in genetic
predisposition,” she says.
Similarly, a year-long weight-loss study by Christopher Gardner
and his colleagues at Stanford
University in California found no
significant differences between
a healthy low-fat diet versus a low-
carbohydrate diet – even when
individuals were assigned to a
regime that matched their genetic
predisposition to one or the other.
“Caution is needed when
genetic tests are negative – does
that give people a licence to
eat whatever foods they like in
whatever amounts? Not really,”
says Forouhi. Other studies
have found that personalised
nutrition may be more beneficial
when it is based on characteristics
such as age, sex, obesity status
and ethnic group.
DNANudge acknowledges that
DNA isn’t the whole story, and its
wristband doubles as an activity
tracker, flashing amber when a
person is sedentary for too long.
“I would never recommend
anything just based upon pure
DNA,” says Toumazou.
“More robust evidence is
needed to support the efficacy
and additional benefits of
personalised nutrition beyondmore traditional nutrition
intervention approaches, such
as those targeted towards eating
more fruit and veg, or fewer foods
that are high in free sugars,” says
a spokesperson for the British
Nutrition Foundation, a charity
focused on nutrition science.
And what about genetic
privacy? DNANudge doesn’t
collect individuals’ genetic data,
only storing an encrypted version
of a person’s recommended
dietary factors, says Toumazou.
The supermarket items
customers scan will also be
recorded in an anonymised way.
This will enable DNANudge to
request that manufacturers and
retailers stop selling regularly
scanned products that are
unsuitable for large groups
of people, says Toumazou.
This could also be a source
of valuable information about
people’s everyday shopping
choices. DNANudge has an
ongoing research collaboration
with UK-based supermarket
chain Waitrose to study the
effect of the technology on
pre-diabetic customers. ❚Gene-based diets
TIMBODDY^ FORNEW^ SCIENTISTCan you shop with your DNA?
A start-up wants to tell you what to eat based on genetics, reports Donna Lu
Reporter Donna Lu uses
a swab kit in DNANudge
and, above, tries the
firm’s wristband, which
scans packets to approve
or discourage purchases“There is little research to
suggest that eating based
on your genes conveys
any significant benefits”