Establishing the Glycaemic Index of Fruit Drinks Using Different Measurement Methodologies

NCT06898840 | Recruiting

• 1 other identifier: 7134-9931
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

Brief Summary

Glycaemic responses to carbohydrates ingested as fruit sugars may vary depending on factors inherent to the fruit and the type of sugar. The aim of this project is to investigate the glycaemic responses to a range of commercially available fruit drinks and to establish the glycaemic index for each product relative to a glucose reference. Differences in recorded responses could also be influenced by the sample type (capillary blood vs interstitial fluid) and participant characteristics. Participants will ingest 8 test drinks including 5 different fruit drinks (OJ, AJ, S\&B, ENERGISE, BLUE), each matched for carbohydrate to the glucose reference (CONTROL) which will be sampled two times, an additional sample of one of the smoothies (S\&B) will also be replicated. Fingerstick capillary blood sampling alongside dual sited continuous glucose monitors (CGM) will measure glucose and lactate concentrations, subjective appetite sensations will also be recorded. The tests will follow best practice guidelines for glycaemic index testing. These data will provide insight into how differing formulations can alter the glycaemic responses to fruit drinks, and whether sampling technique can affect the interpretations of measurement.

Conditions

Glycaemic Index; Glycaemic Response Measurements

Keywords

Fruit Drinks; Glycaemic Index

Outcome Measures

Primary Outcomes (1)

• Glycaemic indices for 5 test drinks measured using capillary blood samples

  Glycaemic indices \[2-hour incremental area under the glucose curve (mmol/L-1x120 minutes) for each of the 5 test drinks relative to mean value of control conditions (CONTROL, REPLICATE CONTROL), expressed as a percentage\] in capillary blood samples

  120 minutes

Secondary Outcomes (1)

• Glycaemic index of all conditions with capillary blood samples vs CGM

  120 minutes

Other Outcomes (17)

• Comparisons between conditions in glucose concentration in capillary samples

  120 minutes

• Comparisons between conditions in glucose concentration in capillary samples

  120 minutes

• Comparisons between conditions in glucose concentration in capillary samples

  120 minutes

Study Arms (8)

CONTROL

ACTIVE COMPARATOR

50 g glucose (55 g dextrose powder accounting for hydration) plus 641 mL water

Other: Fruit drink

REPLICATE CONTROL

ACTIVE COMPARATOR

50 g glucose (55 g dextrose powder accounting for hydration) plus 641 mL water

Other: Fruit drink

S&B

EXPERIMENTAL

417 mL of commercially available "Strawberries \& Bananas" fruit smoothie providing 50 g carbohydrate \[strawberries (31%), apples, bananas (22%), white grapes, oranges, blackcurrants\]. Plus 224 mL water to standardise volume

Other: Fruit drink

REPLICATE S&B

EXPERIMENTAL

417 mL of commercially available "Strawberries \& Bananas" fruit smoothie providing 50 g carbohydrate \[strawberries (31%), apples, bananas (22%), white grapes, oranges, blackcurrants\]. Plus 224 mL water to standardise volume

Other: Fruit drink

OJ

EXPERIMENTAL

641 mL of commercially available "Smooth Orange Juice" providing 50 g of carbohydrate \[100% oranges\]

Other: Fruit drink

AJ

EXPERIMENTAL

455 mL commercially available "Apple Juice" providing 50 g of carbohydrate \[apples, ascorbic acid\]. Plus 186 mL water to standardise volume

Other: Fruit drink

ENERGISE

EXPERIMENTAL

417 mL of commercially available "Energise Super Smoothie" providing 50 g carbohydrate \[apples (50%), red grapes, bananas, strawberries (10%), blackcurrants, sour cherries (3.3%), pressed beetroot, flax seeds (0.56%), guarana infusion (0.01%), vitamins B1, B2, B3, B6, C \& E\]. Plus 224 mL water to standardise volume

Other: Fruit drink

BLUE

EXPERIMENTAL

521 mL of commercially available "Bolt from the Blue" juice drink providing 50 g carbohydrate \[apple (66%), coconut water (18%), white grapes, white guava (5.2%), passion fruit, lime (0.87%), spirulina extract (0.81%) vitamins B1, B2, B3, B6, C \& E\]. Plus 120 mL water to standardise volume

Other: Fruit drink

Interventions

Fruit drink OTHER

Commercially available fruit drinks or smoothies

AJ; BLUE; CONTROL; ENERGISE; OJ; REPLICATE CONTROL; REPLICATE S&B; S&B

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age: 18-65 years
• Body mass index 18-30 kg/m2

You may not qualify if:

• diagnosis of any form of diabetes
• intolerances or allergies to any of the study procedures (e.g. fructose/inulin intolerance)
• Fructose malabsorption
• Inborn errors of fructose metabolism (e.g. fructokinase deficiency, aldolase B deficiency, fructose-1,6-bisphosphatase deficiency)
• pregnant or lactating
• any condition that could introduce bias to the study (e.g. diagnoses of lipid disorders, including cardiovascular disease, or therapies that alter lipid or glucose metabolism, such as statins or niacin).

Sponsors & Collaborators

• University of Bath: lead

Study Sites (1)

Department for Health, University of Bath

Bath, BA2 7AY, United Kingdom

RECRUITING

Related Publications (1)

• Gonzalez JT. Are all sugars equal? Role of the food source in physiological responses to sugars with an emphasis on fruit and fruit juice. Eur J Nutr. 2024 Aug;63(5):1435-1451. doi: 10.1007/s00394-024-03365-3. Epub 2024 Mar 16.

  PMID: 38492022 BACKGROUND

Central Study Contacts

Emma L Greatorex Brooks

CONTACT

+44 (0) 1225 388388; elgb21@bath.ac.uk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: PhD Researcher

Model Details: Randomised, controlled, replicate crossover trial

Study Record Dates

• First Submitted: February 28, 2025
• First Posted: March 27, 2025
• Study Start: March 13, 2025
• Primary Completion: July 31, 2025
• Study Completion: September 30, 2025
• Last Updated: March 27, 2025

Record last verified: 2025-01

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: These will become available at the point of publication permanently

Locations

GB (1)