Personalised ‘DNA diet’ may reduce blood glucose and diabetes risk

The research, which was published in Nature Scientific Reports, involved 148 people with high blood sugar levels who were at risk of developing type 2 diabetes.

It found that personalised dietary advice informed by individuals’ genetics, combined with face-to-face coaching from a healthcare professional, was more effective at reducing blood glucose levels than standard dietary coaching.

In the UK, this is based on advice from the National Institute for Health and Care Excellence (NICE), which outlines interventions to improve people’s diets and increase their physical activity. Such interventions, however, can be expensive and labour-intensive, requiring multiple appointments. 

The researchers, from Imperial College London and its spinout DnaNudge, a consumer genetics services provider, say their findings are a promising example of how genetic data might be leveraged to help prevent long-term conditions.

Joint senior author Regius Professor Chris Toumazou, from Imperial’s Department of Electrical and Electronic Engineering and DnaNudge, said: “Genetic profiles of chronic conditions, such as type 2 diabetes, obesity, hypertension, and blood cholesterol can tell us which foods for individuals might be better or worse at reducing the risk of these conditions, allowing us to specifically tailor advice around their dietary intake of fats, carbohydrates, and other macronutrients.

“Our pilot study, where we apply this to pre-diabetes, shows promising results, suggesting that genetically informed diets could be an effective intervention compared to, or combined with, standard NICE-guided advice.”

Lifestyle changes can halve the likelihood of pre-diabetes progressing to type 2 diabetes

Up to 10% of people with pre-diabetes – when a person’s blood glucose is consistently higher than usual, but not yet high enough to be classed as diabetes – go on to develop the condition each year.

However, unlike diabetes, pre-diabetes is reversible if addressed; lifestyle changes can halve the likelihood of it progressing.

Meanwhile, certain genetic traits can predict an individual’s risk of developing diet-related chronic conditions, underlining the importance of dietary modifications, such as changing salt, fat, and saturated fat to address cardiovascular risk, or changing sugar and saturated fat intake for diabetes risk.

Based on this, DnaNudge created the framework for providing personalised diet plans based on people’s genetic profiles, obtained from a sample of saliva.

To test the effects of DNA-based diets on pre-diabetes, the researchers recruited 148 people with high blood sugar levels and took baseline measurements of fasting plasma glucose (FPG – levels of sugar in the blood between meals) and glycated haemoglobin (HbA1c) blood sugar levels. Participants also completed a questionnaire on how often they consumed certain foods.

The team then randomised participants to one of three groups: the control group, whose subjects received NICE-guided coaching from a dietitian only; the intervention group, whose subjects received coaching and a DNA-based diet; and the exploratory group, whose subjects received no coaching but were self-guided by the DnaNudge app and a wearable device that enabled them to scan barcodes and receive DNA-personalised food and drink recommendations while shopping.

The researchers tested participants’ FPG and HbA1c levels again at six, 12, and 26 weeks. They found no statistically significant difference between the groups at six weeks; however, at 26 weeks, a significant reduction was observed in both FPG and HbA1c in participants using the DNA-based diet, with or without the DnaNudge app, compared with the control group.

At 26 weeks, compared with the control group, the intervention group saw an average reduction in FPG of 0.019 mmol/L and reduction in HbA1c by 0.038 mmol/mol. The exploratory group saw a 0.021 mmol/L reduction in FPG with no reduction in HbA1c.

Joint senior author Professor Nick Oliver, a clinical consultant in diabetes and endocrinology from Imperial’s Department of Metabolism, Digestion, and Reproduction, said: “Prior to progression to type 2 diabetes, people and their healthcare professionals have an opportunity to reduce their risk.

“The NICE guidance for lifestyle change – for example, the inclusion of fruits, vegetables, healthy fats, and whole grains – are evidence-based and effective for a population, but our findings suggest that personalisation by genetically tailoring dietary advice to an individual might have an even greater effect.”

Personalised 'DNA' diet: A cost-effective, easily scalable prevention tool

The researchers said their results should be treated with caution because of the small study size, adding that the results warrant confirmation in a larger randomised controlled trial.

They now intend to run a larger, multinational trial with thousands of participants to validate the results. The larger sample size will also allow them to include results within diverse ethnic groups and genders, which can affect the likelihood of developing type 2 diabetes.

© iStock/fcafotodigital

Joint first author Dr Maria Karvela, from Imperial’s Department of Electrical and Electronic Engineering and DnaNudge, said: “Though clinical research into personalised nutrition and type 2 diabetes is still developing, our study adds to evidence that supports the value of such personalised approaches.

“If validated, our intervention could provide a cost-effective, widely distributable, and easily scalable prevention tool for improving glucose regulation in high-risk individuals.”

The study was funded by DnaNudge and undertaken by the NIHR Imperial Clinical Research Facility at Hammersmith Hospital, Imperial College Healthcare NHS Trust. Toumazou and Karvela are affiliated with DnaNudge.