The Health Effects of Blueberry Anthocyanins in Metabolic Syndrome (the CIRCLES-study)

NCT ID: NCT02035592

Last Updated: 2017-09-29

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

144 participants

Study Classification

INTERVENTIONAL

Study Start Date

2014-01-31

Study Completion Date

2016-11-07

Brief Summary

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The purpose of this study is to determine the dose-dependent impact of 6 month freeze-dried blueberry powder intake on insulin sensitivity and resistance, cardiovascular disease risk factors, and lung and cognitive function in overweight and obese participants with metabolic syndrome. We will also examine acute post-prandial effects of blueberry intake (at baseline and at 6-months).

Detailed Description

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Conditions

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Insulin Resistance Metabolic Syndrome X

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

QUADRUPLE

Participants Caregivers Investigators Outcome Assessors

Study Groups

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Full dose blueberry

26g of freeze dried blueberry powder; equivalent to 2 portions of fresh blueberries per day.

Frequency: 26g per day.

Total duration: 6-month.

Group Type ACTIVE_COMPARATOR

Full dose blueberry

Intervention Type OTHER

Full dose: 26g of freeze dried blueberry powder to be incorporated into the habitual diet.

Dietary restrictions will be observed (i.e. avoidance of blueberry, and restricted intake of anthocyanin rich foods) for 21 days prior to the first assessment visit and throughout the study.

Half dose blueberry

26g of freeze dried powder; containing 13g of freeze dried blueberry powder and 13g of placebo comparator material; equivalent to 1 portion of fresh blueberries per day.

Frequency: 26g per day.

Total duration: 6-month.

Group Type ACTIVE_COMPARATOR

Half dose blueberry

Intervention Type OTHER

Half dose: 26g of freeze dried powder (containing 13g of freeze dried blueberry powder and 13g of placebo comparator material) to be incorporated into the habitual diet.

Dietary restrictions will be observed (i.e. avoidance of blueberry, and restricted intake of anthocyanin rich foods) for 21 days prior to the first assessment visit and throughout the study.

Control

Matched control powder; matched for appearance, taste and sugar content.

Frequency: 26g per day.

Total duration: 6-month.

Group Type PLACEBO_COMPARATOR

Control

Intervention Type OTHER

Control: 26g of placebo comparator material to be incorporated into the habitual diet.

Dietary restrictions will be observed (i.e. avoidance of blueberry, and restricted intake of anthocyanin rich foods) for 21 days prior to the first assessment visit and throughout the study.

Interventions

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Full dose blueberry

Full dose: 26g of freeze dried blueberry powder to be incorporated into the habitual diet.

Dietary restrictions will be observed (i.e. avoidance of blueberry, and restricted intake of anthocyanin rich foods) for 21 days prior to the first assessment visit and throughout the study.

Intervention Type OTHER

Half dose blueberry

Half dose: 26g of freeze dried powder (containing 13g of freeze dried blueberry powder and 13g of placebo comparator material) to be incorporated into the habitual diet.

Dietary restrictions will be observed (i.e. avoidance of blueberry, and restricted intake of anthocyanin rich foods) for 21 days prior to the first assessment visit and throughout the study.

Intervention Type OTHER

Control

Control: 26g of placebo comparator material to be incorporated into the habitual diet.

Dietary restrictions will be observed (i.e. avoidance of blueberry, and restricted intake of anthocyanin rich foods) for 21 days prior to the first assessment visit and throughout the study.

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

* Men and postmenopausal women (≥ 1 year since last menstruation)
* 50 to 75 years old
* BMI of ≥ 25 kg/m2
* 3 characteristics of metabolic syndrome i.e: Waist circumference ≥ 102 cm for men, ≥ 88 cm for women; Triglycerides ≥ 1.7 mmol/L (or drug treatment for elevated triglycerides); HDL-cholesterol \< 1.0 mmol/L for men, \< 1.3 mmol/L for women (or drug treatment for low HDL-cholesterol); Blood pressure ≥ 130 mm Hg systolic and/or ≥ 85 mm Hg diastolic blood pressure; Fasting blood glucose ≥ 5.56 mmol/L
* Successful biochemical, haematological and urinalysis assessment at screening

Exclusion Criteria

* Current smokers, or ex-smokers ceasing \< 6 months ago
* Existing or significant past medical history of vascular disease or medical conditions likely to affect the study measures
* Fructose intolerance or known allergies to the intervention treatments
* On therapeutic diets or having experienced substantial weight loss within 3 months of screening
* Taking flavonoid containing supplements (and unwilling to cease intake during, and 1 month preceding the trial)
* Planning on altering consumption of vitamin supplements / fish oil capsules during the course of the study.
* Prescribed hypoglycaemic, vasodilators or HRT medication.
* Unsatisfactory biochemical, haematological or urinary assessment at screening, or measures considered to be counter indicative for the study
* \< 3 characteristics of the metabolic syndrome.

NB: REC approved NoSA granted to include those on anti-hypertensives (29JUL2014)
Minimum Eligible Age

50 Years

Maximum Eligible Age

74 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Harvard School of Public Health (HSPH)

OTHER

Sponsor Role collaborator

University of East Anglia

OTHER

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Aedin Cassidy, PhD

Role: PRINCIPAL_INVESTIGATOR

University of East Anglia

Locations

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Harvard School of Public Health

Boston, Massachusetts, United States

Site Status

Addenbrooke's hospital

Cambridge, Cambridgeshire, United Kingdom

Site Status

Norwich Medical School University of East Anglia

Norwich, Norfolk, United Kingdom

Site Status

Norfolk and Norwich University Hospital

Norwich, Norfolk, United Kingdom

Site Status

Countries

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United States United Kingdom

References

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Curtis PJ, van der Velpen V, Berends L, Jennings A, Haag L, Minihane AM, Chandra P, Kay CD, Rimm EB, Cassidy A. Chronic and postprandial effect of blueberries on cognitive function, alertness, and mood in participants with metabolic syndrome - results from a six-month, double-blind, randomized controlled trial. Am J Clin Nutr. 2024 Mar;119(3):658-668. doi: 10.1016/j.ajcnut.2023.12.006. Epub 2024 Feb 6.

Reference Type DERIVED
PMID: 38432713 (View on PubMed)

Curtis PJ, Berends L, van der Velpen V, Jennings A, Haag L, Chandra P, Kay CD, Rimm EB, Cassidy A. Blueberry anthocyanin intake attenuates the postprandial cardiometabolic effect of an energy-dense food challenge: Results from a double blind, randomized controlled trial in metabolic syndrome participants. Clin Nutr. 2022 Jan;41(1):165-176. doi: 10.1016/j.clnu.2021.11.030. Epub 2021 Nov 27.

Reference Type DERIVED
PMID: 34883305 (View on PubMed)

Curtis PJ, van der Velpen V, Berends L, Jennings A, Feelisch M, Umpleby AM, Evans M, Fernandez BO, Meiss MS, Minnion M, Potter J, Minihane AM, Kay CD, Rimm EB, Cassidy A. Blueberries improve biomarkers of cardiometabolic function in participants with metabolic syndrome-results from a 6-month, double-blind, randomized controlled trial. Am J Clin Nutr. 2019 Jun 1;109(6):1535-1545. doi: 10.1093/ajcn/nqy380.

Reference Type DERIVED
PMID: 31136659 (View on PubMed)

Other Identifiers

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R21478-C

Identifier Type: -

Identifier Source: org_study_id