Establishing the Glycaemic Index of Fruit Drinks Using Different Measurement Methodologies

NCT ID: NCT06898840

Last Updated: 2025-03-27

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 10 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-03-13
• Study Completion Date: 2025-09-30

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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

CONTROL

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

Group Type: ACTIVE_COMPARATOR

Fruit drink

Intervention Type: OTHER

Commercially available fruit drinks or smoothies

REPLICATE CONTROL

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

Group Type: ACTIVE_COMPARATOR

Fruit drink

Intervention Type: OTHER

Commercially available fruit drinks or smoothies

S&B

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

Group Type: EXPERIMENTAL

Fruit drink

Intervention Type: OTHER

Commercially available fruit drinks or smoothies

REPLICATE S&B

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

Group Type: EXPERIMENTAL

Fruit drink

Intervention Type: OTHER

Commercially available fruit drinks or smoothies

OJ

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

Group Type: EXPERIMENTAL

Fruit drink

Intervention Type: OTHER

Commercially available fruit drinks or smoothies

AJ

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

Group Type: EXPERIMENTAL

Fruit drink

Intervention Type: OTHER

Commercially available fruit drinks or smoothies

ENERGISE

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

Group Type: EXPERIMENTAL

Fruit drink

Intervention Type: OTHER

Commercially available fruit drinks or smoothies

BLUE

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

Group Type: EXPERIMENTAL

Fruit drink

Intervention Type: OTHER

Commercially available fruit drinks or smoothies

Interventions

Fruit drink

Commercially available fruit drinks or smoothies

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

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

Exclusion Criteria

• 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).

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Bath

OTHER

Sponsor Role: lead

Responsible Party

Emma Greatorex Brooks

PhD Researcher

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Department for Health, University of Bath

Bath, , United Kingdom

Site Status: RECRUITING

Countries

United Kingdom

Central Contacts

Emma L Greatorex Brooks

Role: CONTACT

elgb21@bath.ac.uk

+44 (0) 1225 388388

References

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.

Reference Type: BACKGROUND

PMID: 38492022 (View on PubMed)

Other Identifiers

7134-9931

Identifier Type: -

Identifier Source: org_study_id