In a colourful shop in Covent Garden, London, the tagline “Shop with your DNA” is brightly emblazoned above customers’ heads. One wall is lined with rows of multicoloured cubicles that contain printer-like DNA testing devices.
I’m stood in DNA Nudge, a shop which opened in London this week. It claims to help people make better food shopping choices based on their DNA and lifestyle factors such as physical activity, but how effective personalised diets based on genetic testing are remains to be seen.
DNA swabs are being analysed in the store. Customers rub the inside of their cheeks using 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.
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This information is turned into a personal profile that recommends amounts of dietary components, including salt, fat and sugar. For £80, customers can then purchase a wristband for scanning barcodes on supermarket foods. The wristband flashes red or green depending on whether an item “fits” a person’s dietary intake profile.
For someone who is predisposed to having high blood pressure, for example, the wristband may flash red for an item high in salt. A connected smartphone app would then suggest alternatives in the same food category. DNA Nudge has a database of items found in most major UK supermarkets to make this function work.
I tested a shop assistant’s wristband on some cereal, which gave her the green light on chocolate chip Weetabix. It feels strange to have a piece of tech telling you what you should and shouldn’t eat – kind of like having a traffic light for a diet coach.
“The best diet is the diet you don’t know you’re having,” says DNA Nudge CEO Chris Toumazou. “Mindless overeating becomes mindless healthy overeating.”
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 which found that the link between diet and 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 by Christopher Gardner and his colleagues at Stanford University in California found no significant differences between a healthy low-fat versus low-carbohydrate diet – even when individuals were assigned to a regime that matched their genetic predisposition or insulin resistance status.
“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. have found that personalised nutrition may be more beneficial when it is based on characteristics such as age, sex, level of obesity and ethnic group.
“I don’t believe in genes on their own. I would never, ever recommend anything just based upon pure DNA” because lifestyle factors such as the amount of time spent sitting or sedentary have a major impact, says Toumazou. DNA Nudge’s wristband doubles as an activity tracker, flashing amber when a person is sedentary for too long.
“More robust evidence is needed to support the efficacy and additional benefits of personalised nutrition beyond more 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.
Then there is the issue of privacy. DNA Nudge 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 DNA Nudge to request that manufacturers and retailers stop stocking 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. DNA Nudge has an ongoing research collaboration with supermarket firm Waitrose & Partners, studying the effect of the technology on pre-diabetic customers.
