Broccoli Effect on Glycated Haemoglobin (HbA1c)

Not Applicable

• Conditions: Pre-diabetes
• Interventions: Other: Courgette soup; Other: Broccoli soup

• Registration Number: NCT05367024
• Lead Sponsor: Quadram Institute Bioscience

Brief Summary

Broccoli has shown to normalise elevated blood sugars when eaten over long period of time. Individuals with pre-diabetes have higher than normal blood sugar levels. In this study, investigators are trying to understand how broccoli, when eaten as a soup, affects blood sugar levels in individuals with pre-diabetes.

Detailed Description

The BETA study is a 36-week randomized, double-blind, placebo-controlled, two-arm crossover intervention study conducted at the Quadram Institute Clinical Research Facility (QI CRF), Norwich, UK. Investigators are seeking adults with pre-diabetes, to determine whether broccoli soups affect glucose metabolism, compared to a similar soup containing courgette. There are a total of 9 clinical visits (1 screening visit, 4 short visits, and 4 oral glucose tolerance testing visits). Investigators will assess blood samples for glycated hemoglobin (HbA1c), fasting plasma glucose, insulin, fructosamine, cholesterol and triglycerides. Investigators will also quantify the metabolites in urine through analytical analysis and determine whether gene expression is altered by the soups through RNA sequencing. Participants will consume one of two soups (broccoli or courgette) for the first intervention period then after a twelve-week washout phase (soup holiday), participants will crossover and consume the other soup for the second intervention period. For each intervention period, soups will be consumed three times a week per twelve-week period. Investigators will ask the participant to complete lifestyle questionnaires regarding their physical activity and dietary pattern.

Study Timeline

• Study Start: 2021-09-27
• Study First Submitted: 2021-10-04
• Study First Submitted QC: 2022-05-04
• Study First Posted: 2022-05-10
• Status Verified: 2024-05
• Last Update Submitted: 2024-05-05
• Last Update Posted: 2024-05-07
• Primary Completion: 2025-04
• Study Completion: 2025-12

Recruitment & Eligibility

• Status: ENROLLING_BY_INVITATION
• Sex: All
• Target Recruitment: 35

Inclusion Criteria

• Individuals with prediabetes (confirmed through screening)
• Aged 18 and older.
• Body Mass Index (BMI) between 18.5 - 35 kg/m2.
• Living within 40 miles from the Norwich Research Park.

Exclusion Criteria

The participant will not be able to take part if they('re):

• Screening test results indicate they are not suitable to take part in this study such as HbA1c level at screening visit of < 42 mmol/mol (healthy) and > 47 mmol/mol (diabetes) and BMI at screening visit < 18.5 kg/m2 (underweight) and > 35 kg/m2 (extremely obese).
• Have a known allergy to any of the components (broccoli, courgette, milk, lactose, or gluten) of the test soups.
• Have been diagnosed or have a history of blood or clotting disorders such as anaemia or thrombosis.
• Have been treated for heart disease, cancer, or diabetes.
• Are immunocompromised due to medications or viral infection such human immunodeficiency virus (HIV).
• Have low or high blood pressure with hypertension medication (≤90/60, ≥160/100 respectively would be classed as abnormal).
• Have any acute or chronic illnesses that affects the outcome of the study such as a gastrointestinal disorder. This will be assessed on a case by case basis by QI medical advisor.
• Plan to become pregnant during the study duration, pregnant or breastfeeding.
• Frequently take medications that may interfere with sugar metabolism or absorption such as laxatives, steroids, dietary supplements, or anti-inflammatory medications. This will be assessed on a case by case basis by QI medical advisor.
• Drink more than 14 alcohol units/week.
• Smoke socially or on occasion more than 12.5 grams or 20 cigarettes/week
• Vegan or any dietary restrictions that prevent the consumption of study soups or follow a diet programme which requires fasting for multiple days.
• Are a registered blood donor and have donated a large quantity of blood within the last 16 weeks. Registered blood donors should abstain from blood donations for the duration of the study.
• Are unable to give written or verbal informed consent
• Unable to provide GP contact details.
• Are participating in another dietary intervention study nor given blood in another dietary study in the last 3 months.
• Are related to or living with any member of the study team or part of the management/supervisory structure of the Chief Investigator.
• Have symptoms of COVID-19, been asked to self-isolate, or have been diagnosed with COVID-19 in the last 14 days.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Courgette soup	Courgette soup	The soup will be made with a commercially available dried vegetable soup supplemented with courgette powder.
Broccoli soup	Broccoli soup	The soup will be made with a commercially available dried vegetable soup supplemented with broccoli powder.

Primary Outcome Measures

Name	Time	Method
Change in glycated haemoglobin (HbA1c) after broccoli and courgette soup interventions	Week: 0, 12, 24 and 36.	Comparison of fasting blood for HbA1c at baseline and after soup interventions

Secondary Outcome Measures

Name	Time	Method
Change in fasting plasma insulin (mmol/L) after broccoli and courgette soup interventions	Week: 0 to12 and 24 to 36.	Comparison of fasting plasma insulin between baseline and at 12 weeks and washout (24 weeks) and 36 weeks.
Change in broccoli metabolites (glucosinolates, sulforaphane, and S-methyl cysteine sulfoxide) in 24 hour urine collection	Week: 0, 12, 24, and 36.	Quantification of broccoli metabolite excretion into urine metabolites will be measured from 24-hour urine collections using targeted metabolite analysis of glucosinolates, sulforaphane, and S-methyl cysteine sulfoxide. These metabolites will be used to define relationships between dietary intake, broccoli metabolism and the biological outcomes
Change in fasting serum triglycerides (mmol/L) after broccoli and courgette soup interventions	Week: 0 to12 and 24 to 36.	Comparison of fasting serum triglycerides between baseline and at 12 weeks as well as washout (24 weeks) and 36 weeks.
Change in fasting serum cholesterol (mmol/L) after broccoli and courgette soup interventions	Week: 0 to12 and 24 to 36.	Comparison of fasting serum cholesterol between baseline and at 12 weeks as well as washout (24 weeks) and 36 weeks.
Change in postprandial capillary glucose concentration	3.5 hours	Capillary glucose concentration will be measured by finger prick after administration of a glucose challenge using a standardized 75g glucose beverage (GlucosePro). Measurements will be taken -15, -10, -5, 15, 30, 45, 60, 90, 120, 150, 180, 210 min post glucose beverage at Week: 0, 12, 24 and 36.
Change in fasting plasma glucose (mmol/l) after broccoli and courgette soup interventions	Week: 0 to12 and 24 to 36.	Comparison of fasting plasma glucose between baseline and at 12 weeks and washout (24 weeks) and 36 weeks.
Change in fasting serum fructosamine (µmol/L) after broccoli and courgette soup interventions	Week: 0 to12 and 24 to 36.	Comparison of fasting serum fructosamine between baseline and at 12 weeks as well as washout (24 weeks) and 36 weeks.
Treatment effects on whole blood gene expression from RNAseq	up to 36 weeks.	The effect of soup consumption will be tested using edgeR and Limma to fit linear models to gene expression data. False discovery rate will be corrected using the Benjamin Hochberg procedure

Trial Locations

Locations (1)

Quadram Institute Bioscience; 🇬🇧 Norwich, United Kingdom