Effect of Dragon Fruit Consumption in Individuals at Risk of Type 2 Diabetes

This will be a parallel study in which two different treatments will be evaluated to determine their effect on glucose, blood pressure, and other outcomes including dietary assessment in individuals at risk of diabetes. The study will last 4 weeks and will involve 3 testing sessions. The participants (N=32) will be randomly divided into two groups and asked either to consume daily a dragon fruit based beverage or to follow a general health guidelines for 4 weeks. The treatment will be taken once a day and a 24 hours dietary recall will be recorded three times during the intervention; the results provided will contribute to understanding the role of polyphenols from the edible products based on dragon fruit on glucose metabolism, blood pressure and linked biomarkers.

Treatment for testing group 1, will include an advice that involve following general health guidelines based on Eatwell Guide and guidelines for type 2 diabetes prevention from the National Institute for Health and Care Excellence (NICE) for 4 weeks. Treatment for testing group 2, will involve drinking a dragon fruit based beverage daily for 4 weeks.

The first visit will start by asking participants to take part in a 24 hours dietary recall and by recording anthropometric measurements. Blood pressure will be taken after 10 minutes of rest (three measurements at five minutes intervals). Venous blood sample will be taken by venepunture to determine fasting blood glucose and biomarkers. Then a standard glucose drink (75g of glucose in 250 ml of water) will be given to determine glucose tolerance, a further venous sample will be taken after 2 hours. Between the 2 hours, finger-prick blood samples will be taken at 0, 15, 30, 45, 60, 90 and 120 minutes intervals, to evaluate the glycaemic and insulin response profile. The treatment will be given to the participant to start the intervention.

The second session will be held 2 weeks after the treatment begins and the protocol established above for the first session will be followed.

After 4 weeks of treatment the third session will be conducted, as mentioned in first and second sessions. Anthropometric measurements will be recorded.

Inclusion criteria

• Aged 18-50 years who fulfil at least two of the following inclusion criteria:

• Have a first grade relative with diabetes (parent, brother, or sister)
• Have a BMI ≥ 25.0.
• Have a sedentary lifestyle.

Exclusion criteria

• • Covid-19 related symptoms, during the last 7 days.

• Allergies to dragon fruit.
• Diabetes, hypertension, or renal disease.
• Medication that requires prescription.
• Pregnant or breastfeeding.