A Single Supplement of a Standardised Bilberry Extract Modifies Glycaemic Response - Study Results

Study Type:	Interventional
Study Design:	Allocation: Randomized; Endpoint Classification: Efficacy Study; Intervention Model: Crossover Assignment; Masking: Double Blind (Subject, Investigator); Primary Purpose: Treatment
Condition:	Type 2 Diabetes
Interventions:	Dietary Supplement: Bilberry capsule first, then control cap Dietary Supplement: Control capsule first then bilberry cap

Participant Flow

Recruitment Details

Key information relevant to the recruitment process for the overall study, such as dates of the recruitment period and locations
Eight male volunteer subjects with T2D controlled by diet and lifestyle alone or with impaired glucose tolerance were recruited from the Aberdeen area of the UK. Subjects were only included if they were not on any special religious or prescribed diet and had a stable weight.

Pre-Assignment Details

Significant events and approaches for the overall study following participant enrollment, but prior to group assignment
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Reporting Groups

	Description
Single Control Capsule First Then Bilberry Capsule	In a cross-over design, volunteers (n 8) were randomised and double-blinded into two groups matched for BMI as well as age and given a single capsule of either 0·47 g of Mirtoselect® (a standardised bilberry extract (36 % (w/w) anthocyanins)) which equates to about 50 g of fresh bilberries formulated in gelatin capsules or a control capsule consisting of microcrystalline cellulose in an opaque gelatin capsule, followed by oral glucose tolerance testing (OGTT). The reverse procedure was conducted following a 2-week washout period. The volunteers were asked to consume a low-phytochemical diet 3 d before taking the capsule and for the 24 h after taking the capsule on both occasions. In addition the volunteers were asked to record what they ate over the same period in a food diary to ensure that they adhered to the low-phytochemical diet. Subjects were reimbursed travelling expenses on completion of the study.
Single Bilberry Capsule First Then Control Capsule	In a cross-over design, volunteers (n 8) were randomised and double-blinded into two groups matched for BMI as well as age and given a single capsule of either 0·47 g of Mirtoselect® (a standardised bilberry extract (36 % (w/w) anthocyanins)) which equates to about 50 g of fresh bilberries formulated in gelatin capsules or a control capsule consisting of microcrystalline cellulose in an opaque gelatin capsule, followed by oral glucose tolerance testing (OGTT). The reverse procedure was conducted following a 2-week washout period. The volunteers were asked to consume a low-phytochemical diet 3 d before taking the capsule and for the 24 h after taking the capsule on both occasions. In addition the volunteers were asked to record what they ate over the same period in a food diary to ensure that they adhered to the low-phytochemical diet. Subjects were reimbursed travelling expenses on completion of the study.

Description

Single Control Capsule First Then Bilberry Capsule

In a cross-over design, volunteers (n 8) were randomised and double-blinded into two groups matched for BMI as well as age and given a single capsule of either 0·47 g of Mirtoselect® (a standardised bilberry extract (36 % (w/w) anthocyanins)) which equates to about 50 g of fresh bilberries formulated in gelatin capsules or a control capsule consisting of microcrystalline cellulose in an opaque gelatin capsule, followed by oral glucose tolerance testing (OGTT). The reverse procedure was conducted following a 2-week washout period. The volunteers were asked to consume a low-phytochemical diet 3 d before taking the capsule and for the 24 h after taking the capsule on both occasions. In addition the volunteers were asked to record what they ate over the same period in a food diary to ensure that they adhered to the low-phytochemical diet. Subjects were reimbursed travelling expenses on completion of the study.

Single Bilberry Capsule First Then Control Capsule

In a cross-over design, volunteers (n 8) were randomised and double-blinded into two groups matched for BMI as well as age and given a single capsule of either 0·47 g of Mirtoselect® (a standardised bilberry extract (36 % (w/w) anthocyanins)) which equates to about 50 g of fresh bilberries formulated in gelatin capsules or a control capsule consisting of microcrystalline cellulose in an opaque gelatin capsule, followed by oral glucose tolerance testing (OGTT). The reverse procedure was conducted following a 2-week washout period. The volunteers were asked to consume a low-phytochemical diet 3 d before taking the capsule and for the 24 h after taking the capsule on both occasions. In addition the volunteers were asked to record what they ate over the same period in a food diary to ensure that they adhered to the low-phytochemical diet. Subjects were reimbursed travelling expenses on completion of the study.

Participant Flow: Overall Study

	Single Control Capsule First Then Bilberry Capsule	Single Bilberry Capsule First Then Control Capsule
STARTED	4 ^[1]	4 ^[1]
COMPLETED	4 ^[1]	4 ^[1]
NOT COMPLETED	0	0

[1]	In a cross-over design, volunteers (n=8) were randomised and double blinded into two groups (n=4)

Baseline Characteristics

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Population Description

Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate.
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Reporting Groups

	Description
Bilberry Capsule First, Then Control Capsule	In a cross-over design, eight volunteers were randomised and double-blinded into two groups matched for BMI as well as age and given a single capsule of either 0·47 g of Mirtoselect® (a standardised bilberry extract (36 % (w/w) anthocyanins)) which equates to about 50 g of fresh bilberries formulated in gelatin capsules or a control capsule consisting of microcrystalline cellulose in an opaque gelatin capsule, followed by oral glucose tolerance testing (OGTT). The reverse procedure was conducted following a 2-week washout period. The volunteers were asked to consume a low-phytochemical diet 3 d before taking the capsule and for the 24 h after taking the capsule on both occasions. In addition the volunteers were asked to record what they ate over the same period in a food diary to ensure that they adhered to the low-phytochemical diet. Subjects were reimbursed travelling expenses on completion of the study.
Control Capsule First, Then Bilberry Capsule	In a cross-over design, eight volunteers were randomised and double-blinded into two groups matched for BMI as well as age and given a single capsule of either 0·47 g of Mirtoselect® (a standardised bilberry extract (36 % (w/w) anthocyanins)) which equates to about 50 g of fresh bilberries formulated in gelatin capsules or a control capsule consisting of microcrystalline cellulose in an opaque gelatin capsule, followed by oral glucose tolerance testing (OGTT). The reverse procedure was conducted following a 2-week washout period. The volunteers were asked to consume a low-phytochemical diet 3 d before taking the capsule and for the 24 h after taking the capsule on both occasions. In addition the volunteers were asked to record what they ate over the same period in a food diary to ensure that they adhered to the low-phytochemical diet. Subjects were reimbursed travelling expenses on completion of the study.
Total	Total of all reporting groups

Baseline Measures

	Bilberry Capsule First, Then Control Capsule	Control Capsule First, Then Bilberry Capsule	Total
Number of Participants [units: participants]	4	4	8
Age [units: participants]
<=18 years	0	0	0
Between 18 and 65 years	4	4	8
>=65 years	0	0	0
Age [units: years] Mean ± Standard Deviation	62 ± 5	62 ± 5	62 ± 5
Gender [units: participants]
Female	0	0	0
Male	4	4	8
Region of Enrollment [units: participants]
United Kingdom	4	4	8
BMI [units: Kg/m2] Mean ± Standard Deviation	30 ± 4	30 ± 4	30 ± 4

Outcome Measures

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1. Primary:

Plasma Glucose iAUC (Incremental Area Under the Curve; mM*Min) [ Time Frame: Plasma was collected at -15, -10 and -5 (fasted) and at 15, 30, 45, 60, 90, 120, 150 and 300 min post capsule ]

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2. Primary:

Plasma Insulin iAUC (Incremental Area Under the Curve; ng/ml*Min) [ Time Frame: Plasma was collected at -15, -10 and -5 (fasted) and at 15, 30, 45, 60, 90, 120, 150 and 300 min after the capsule ]

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3. Secondary:

Bioavailability in Plasma [ Time Frame: Plasma will also be collected -15,-10, -5, 15, 30, 45, 60, 90, 120, 150, and 300 minutes and 24 hours post intervention ]

Results not yet reported. Anticipated Reporting Date: 01/2014 Safety Issue: No

4. Secondary:

Bioavailability in Urine [ Time Frame: Urine will also be collected (if possible) 0, 1, 3 and 5 hours, with all urine collected within the 24 hour time period post intervention ]

Results not yet reported. Anticipated Reporting Date: 01/2014 Safety Issue: No

Serious Adverse Events

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Other Adverse Events

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Limitations and Caveats

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Limitations of the study, such as early termination leading to small numbers of participants analyzed and technical problems with measurement leading to unreliable or uninterpretable data
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More Information

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Certain Agreements:

All Principal Investigators ARE employed by the organization sponsoring the study.

Results Point of Contact:

Name/Title: Dr Nigel Hoggard
Organization: University of Aberdeen Rowett Institute of Nutrition and Health
phone: [+44] (0) 1224 438700
e-mail: N.Hoggard@abdn.ac.uk

Publications:

Martineau LC, Couture A, Spoor D, Benhaddou-Andaloussi A, Harris C, Meddah B, Leduc C, Burt A, Vuong T, Mai Le P, Prentki M, Bennett SA, Arnason JT, Haddad PS. Anti-diabetic properties of the Canadian lowbush blueberry Vaccinium angustifolium Ait. Phytomedicine. 2006 Nov;13(9-10):612-23. Epub 2006 Sep 18.

Zafra-Stone S, Yasmin T, Bagchi M, Chatterjee A, Vinson JA, Bagchi D. Berry anthocyanins as novel antioxidants in human health and disease prevention. Mol Nutr Food Res. 2007 Jun;51(6):675-83. Review.

Lau FC, Bielinski DF, Joseph JA. Inhibitory effects of blueberry extract on the production of inflammatory mediators in lipopolysaccharide-activated BV2 microglia. J Neurosci Res. 2007 Apr;85(5):1010-7.

DeFuria J, Bennett G, Strissel KJ, Perfield JW 2nd, Milbury PE, Greenberg AS, Obin MS. Dietary blueberry attenuates whole-body insulin resistance in high fat-fed mice by reducing adipocyte death and its inflammatory sequelae. J Nutr. 2009 Aug;139(8):1510-6. doi: 10.3945/jn.109.105155. Epub 2009 Jun 10.

Responsible Party:	University of Aberdeen
ClinicalTrials.gov Identifier:	NCT01245270 History of Changes
Other Study ID Numbers:	REC 10/S0801/54, 902
Study First Received:	November 16, 2010
Results First Received:	August 23, 2013
Last Updated:	November 17, 2014
Health Authority:	United Kingdom: Research Ethics Committee