Wearing continuous blood glucose monitors causes anxiety

Diet firms offering blood sugar monitors are potentially causing healthy people to develop anxiety and eating disorders, experts warned today.

Several firms, including the ZOE programme — founded by diet guru Professor Tim Spector — offer the high-tech gadgets, called continuous glucose monitors (CGMs), which track a customer's blood sugar levels via a stick-on patch on their arm.

This beams information to a smartphone app that records these 'spikes', which occur when the sugar from digested food enters the blood supply.

Zoe claims on its website that blood sugar spikes can, over time, lead to an increased risk of heart disease, and offers a diet to help minimise them.

However, several experts have questioned the research evidence behind Zoe's claim, together with other similar programmes, and said they could trigger anxiety and an unhealthy obsession with 'pure food' among users.

Several firms, including the ZOE programme — founded by diet guru Professor Tim Spector — offer the high-tech gadgets, called continuous glucose monitors (CGMs), which track a customer's blood sugar levels via a stick-on patch on their arm

The devices – which are no larger than a £2 coin – beam updates on blood sugar levels to the user's phone

Blood sugar monitors have been used for years to help people with diabetes, a condition that causes a person's blood sugar level to become too high, for years.

However, a major review by researchers at University College London (UCL) and Birmingham Children’s Hospital has found a lack of evidence to support the use of the devices in people without diabetes.

Senior author on the study and dietitian Dr Adrian Brown of UCL's said: 'At the present time, CGMs can be sold by companies but they are without a medical use.

'We have good evidence that they have transformed the lives of people with type 1 diabetes, and with good effect for people with type 2 diabetes on insulin therapy.

'But for people not living with diabetes, we don't have the same data.'

He added: 'We are not saying CGMs might not have benefit. However, currently, there remains limited evidence to support the claims being made by commercial companies regarding the use of CGMs in people not living with diabetes.'

Dr Brown explained that basis that of what constituted blood sugar spikes varied both between people, within individual themselves, and the devices.

'A person not living with diabetes has a normal blood glucose ranging from between around 3.8 and 7.8,' he said.

'However, on the monitor that could display at readings between 2.6 to 9.4, therefore showing a potential low blood glucose or a high blood glucose, despite (the person) having normal blood glucose.

'This could impact people seeing results that are in fact normal blood glucose readings, and altering their diets accordingly.'

Dr Brown said people without diabetes will experience brief periods of having elevated blood glucose after meals but – as they generally have good blood glucose control anyway – these often return back to normal within one to two hours.

And while people with diabetes may have long periods of elevated blood glucose, which can put their health at risk in the long term, shorter-term spikes after meals have not been linked to long-term poor health outcomes.

Almost 4.3 million people were living with diabetes in 2021/22, according to the latest figures for the UK. And another 850,000 people have diabetes and are completely unaware of it, which is worrying because untreated type 2 diabetes can lead to complications including heart disease and strokes

'I think there needs to be evidence behind some of the advertisement by CGM companies related to the evidence that is currently available,' he said.

'There’s a lot of anecdotal benefits being reported by people that might have used companies.

'However, what’s important is that companies stick to what the published data says.'

Dr Brown also said there needs to be better regulation of the devices overall.

'The review found evidence that, in people not living with diabetes using CGMs, this potentially could cause anxiety about what normal blood glucose is and also how that impacts on their diet,' he said.

'So there is a potential risk for the development of eating disorders such as orthorexia – an unhealthy obsession with eating "pure" food.'

He also called for more independent research into CGMs, considering that the majority of personalised nutrition data has come from industry-funded research.

'The vast majority of data even in people living with diabetes is industry-funded…so there is the need for more independent research to be conducted outside of commercially funded research,' he said.

The new study, published in Diabetic Medicine, included a review of 25 existing pieces of research and warned that CGMs are 'gaining traction among people not living with diabetes'.

The researchers said the current 'regulatory inadequacy' was helping fuel ‘off-label’ CGM distribution.

'We hope this will help to avert the continued misinformation risk to people not living with diabetes and "off-label" exacerbation of health disparities.'

Zoe has been contacted for comment.

An estimated 5.6 million Brits are living with diabetes, 1.2million of which haven't been diagnosed according to charity Diabetes UK.

For the past five years the NHS has been offering diabetes patients CGM monitors to help them keep track of their blood sugar levels, in place of traditional finger-prick blood tests.

The devices – which are no larger than a £2 coin – beam updates on blood sugar levels to the user's phone.

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