Effect of Soft Fruit on Postprandial Blood Glucose

Dietary strategies for alleviating health complications associated with type 2 diabetes (T2D) are being pursued as alternatives to pharmaceutical interventions. Berries such as blackcurrants that are rich in polyphenols may influence carbohydrate digestion and absorption and thus postprandial glycaemia. In addition berries have been reported to alter incretins as well as to have anti-oxidant and anti-inflammatory properties that may also affect postprandial glycaemia. This study investigated the acute affect blackcurrants on glucose metabolism in overweight/obese volunteers .

Study Overview

• Status: Recruiting
• Conditions: Type 2 Diabetes
• Intervention / Treatment: Dietary supplement: Sugar matched water with polycal OGTT; Dietary supplement: Blackcurrants with polycal OGTT; Dietary supplement: Blackcurrants with glucose OGTT; Dietary supplement: Greencurrants with polycal OGTT

Detailed Description

Sixteen overweight/obese volunteers from the Aberdeen area will be recruited into a randomised controlled study. Volunteers will be randomised into four groups matched for BMI and age and given 200 grams of blackcurrants (which contain anthocyanins) or greencurrants (which naturally contain no anthocyanins), followed by an OGTT.

The consumption of the currants will be followed by an oral glucose tolerance test (OGTT) with Polycal (complex carbohydrate) or glucose (simple carbohydrate) as the carbohydrate load.

There will be a one week minimum wash out period between each intervention. All interventions will be randomised and blinded as far as possible in a cross-over design where the volunteers are acting as their own control. The volunteers will be asked to consume a low phytochemical diet three days prior to taking the currants all occasions. In addition, they will be asked to record what they ate over the same period in a simple food diary.

The following intervention will be carried out on 16 overweight/obese male/postmenopausal female non-smoker volunteers:

1. Control: sugar matched (matched to currant sugar content) water with polycal (complex carbohydrate load)
2. Blackcurrants (which contain anthocyanins; 200grams) with polycal (complex carbohydrate load)
3. Blackcurrants (which contain anthocyanins; 200grams) with glucose (simple carbohydrate load)
4. Greencurrants (which naturally contain no anthocyanins; 200grams) with polycal (complex carbohydrate load)

Note: the polycal will contain the equivalent glucose load as given in intervention 3 assuming complete hydrolysis of all carbohydrates.

• Study Type: Interventional
• Enrollment (Anticipated): 16
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Nigel Hoggard, PhD; Phone Number: [+44] (0) 1224 438655; Email: N.Hoggard@abdn.ac.uk

Study Locations

• United Kingdom
  • Aberdeen, United Kingdom, AB21 9SB
    • Recruiting
    • University of Aberdeen Rowett Institute of Nutrition and Health
    • Contact: Nigel Hoggard, PhD; Phone Number: 01224 716655; Email: N.Hoggard@abdn.ac.uk
    • Principal Investigator: Nigel Hoggard, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Obese male or female (postmenopausal) healthy non-smoking volunteers (BMI over 25kg/m2)
• Aged >21 and <70 years

Exclusion Criteria:

• Medical exclusion criteria

• Chronic illness, including:

  • thromboembolic or coagulation disease
  • unregulated thyroid disease
  • kidney disease
  • hepatic disease
  • severe gastrointestinal disorders
  • pulmonary disease (e.g. chronic bronchitis, COPD)
  • diabetes
• Alcohol or any other substance abuse
• Eating disorders
• Psychiatric disorders (including severe depression, lithium treatment, schizophrenia, severe behavioural disorders)
• Non-postmenopausal women
• Medication exclusion criteria
• Oral steroids
• Tricyclic antidepressants, neuroleptics
• Anticoagulants
• Digoxin and anti-arrhythmics
• Chronic use of anti-inflammatories (e.g. high doses of aspirin, ibuprofen), Insulin, -Sulphonylureas, Thiazolidinediones (glitazones), metformin.
• Anti-obesity medication e.g. Orlistat

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Sugar matched water with polycal OGTT; Control: sugar matched (matched to currant sugar content) water with polycal; Blackcurrants (200grams) with polycal; Blackcurrants (200grams) with glucose; Greencurrants (200grams) with polycal Sixteen overweight/obese volunteers from the Aberdeen area will be recruited into a randomised controlled study. Volunteers will be randomised into four groups matched for BMI and age and given 200 grams of blackcurrants (which contain anthocyanins) or greencurrants (which naturally contain no anthocyanins), followed by an OGTT. The OGTT will be carried out with glucose as a simple carbohydrate load or polycal as a complex carbohydrate load. Volunteers will be randomised into four groups (n=4 per group). One week wash out between treatments	Dietary supplement: Sugar matched water with polycal OGTT; Sixteen overweight/obese volunteers from the Aberdeen area will be recruited into a randomised controlled study. Volunteers will be randomised into four groups matched for BMI and age and given 200 grams of blackcurrants (which contain anthocyanins) or greencurrants (which naturally contain no anthocyanins), followed by an OGTT. The consumption of the currants will be followed by an oral glucose tolerance test (OGTT) with Polycal (complex carbohydrate) or glucose (simple carbohydrate) as the carbohydrate load. The equivalent carbohydrate load will be standardised across the groups
Experimental: Blackcurrants with polycal OGTT; Blackcurrants (200grams) with polycal; Blackcurrants (200grams) with glucose; Greencurrants ( 200grams) with polycal; Control: sugar matched (matched to currant sugar content) water with polycal Sixteen overweight/obese volunteers from the Aberdeen area will be recruited into a randomised controlled study. Volunteers will be randomised into four groups matched for BMI and age and given 200 grams of blackcurrants (which contain anthocyanins) or greencurrants (which naturally contain no anthocyanins), followed by an OGTT. The OGTT will be carried out with glucose as a simple carbohydrate load or polycal as a complex carbohydrate load as decribed above. Volunteers will be randomised into four groups (n=4 per group). One week wash out between treatments	Dietary supplement: Blackcurrants with polycal OGTT; Sixteen overweight/obese volunteers from the Aberdeen area will be recruited into a randomised controlled study. Volunteers will be randomised into four groups matched for BMI and age and given 200 grams of blackcurrants (which contain anthocyanins) or greencurrants (which naturally contain no anthocyanins), followed by an OGTT. The consumption of the currants will be followed by an oral glucose tolerance test (OGTT) with Polycal (complex carbohydrate) or glucose (simple carbohydrate) as the carbohydrate load. The equivalent carbohydrate load will be standardised across the groups
Experimental: Blackcurrants with glucose OGTT; Blackcurrants (200grams) with glucose; Greencurrants (200grams) with polycal; Control: sugar matched (matched to currant sugar content) water with polycal; Blackcurrants (200grams) with polycal Sixteen overweight/obese volunteers from the Aberdeen area will be recruited into a randomised controlled study. Volunteers will be randomised into four groups matched for BMI and age and given 200 grams of blackcurrants (which contain anthocyanins) or greencurrants (which naturally contain no anthocyanins), followed by an OGTT. The OGTT will be carried out with glucose as a simple carbohydrate load or polycal as a complex carbohydrate load as decribed above Volunteers will be randomised into four groups (n=4 per group). One week wash out between treatments	Dietary supplement: Blackcurrants with glucose OGTT; Sixteen overweight/obese volunteers from the Aberdeen area will be recruited into a randomised controlled study. Volunteers will be randomised into four groups matched for BMI and age and given 200 grams of blackcurrants (which contain anthocyanins) or greencurrants (which naturally contain no anthocyanins), followed by an OGTT. The consumption of the currants will be followed by an oral glucose tolerance test (OGTT) with Polycal (complex carbohydrate) or glucose (simple carbohydrate) as the carbohydrate load. The equivalent carbohydrate load will be standardised across the groups
Experimental: Greencurrants with polycal OGTT; Greencurrants (200grams) with polycal; Control: sugar matched (matched to currant sugar content) water with polycal; Blackcurrants (200grams) with polycal; Blackcurrants (200grams) with glucose Sixteen overweight/obese volunteers from the Aberdeen area will be recruited into a randomised controlled study. Volunteers will be randomised into four groups matched for BMI and age and given 200 grams of blackcurrants (which contain anthocyanins) or greencurrants (which naturally contain no anthocyanins), followed by an OGTT. The OGTT will be carried out with glucose as a simple carbohydrate load or polycal as a complex carbohydrate load as decribed above. Volunteers will be randomised into four groups (n=4 per group). One week wash out between treatments.	Dietary supplement: Greencurrants with polycal OGTT; Sixteen overweight/obese volunteers from the Aberdeen area will be recruited into a randomised controlled study. Volunteers will be randomised into four groups matched for BMI and age and given 200 grams of blackcurrants (which contain anthocyanins) or greencurrants (which naturally contain no anthocyanins), followed by an OGTT. The consumption of the currants will be followed by an oral glucose tolerance test (OGTT) with Polycal (complex carbohydrate) or glucose (simple carbohydrate) as the carbohydrate load. The equivalent carbohydrate load will be standardised across the groups

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Plasma Glucose Area Under the Curve	Plasma was collected at -15, -10 and -5 (fasted) and at 15, 30, 45, 60, 90, 120, 150 and 300 min post currant ingestion

Secondary Outcome Measures

Outcome Measure	Time Frame
Plasma Insulin Area Under the Curve	Plasma was collected at -15, -10 and -5 (fasted) and at 15, 30, 45, 60, 90, 120, 150 and 300 min post currant ingestion

Collaborators and Investigators

• Sponsor: University of Aberdeen

Study record dates

Study Major Dates

• Study Start: November 1, 2014
• Primary Completion (Anticipated): September 1, 2022
• Study Completion (Anticipated): September 1, 2022

Study Registration Dates

• First Submitted: November 11, 2014
• First Submitted That Met QC Criteria: November 13, 2014
• First Posted (Estimate): November 14, 2014

Study Record Updates

• Last Update Posted (Actual): February 21, 2021
• Last Update Submitted That Met QC Criteria: February 18, 2021
• Last Verified: February 1, 2021

More Information

Terms related to this study

• Keywords: anthocyanin; glucose; polyphenol; blackcurrant; greencurrant; post prandial glucose
• Other Study ID Numbers: Rowett 905

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided