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| Name | Class |
|---|---|
| Harvard School of Public Health (HSPH) | OTHER |
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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).
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Full dose blueberry | Active Comparator | 26g of freeze dried blueberry powder; equivalent to 2 portions of fresh blueberries per day. Frequency: 26g per day. Total duration: 6-month. |
|
| Half dose blueberry | Active Comparator | 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. |
|
| Control | Placebo Comparator | Matched control powder; matched for appearance, taste and sugar content. Frequency: 26g per day. Total duration: 6-month. |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Full dose blueberry | 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. |
| Measure | Description | Time Frame |
|---|---|---|
| Insulin resistance | Assessed, in the fasted state, via HOMA-IR calculation in all participants; indirect assessment. | Chronic (0 to 6 month) |
| Measure | Description | Time Frame |
|---|---|---|
| Insulin resistance | Assessed in a sub-group via hyperinsulinemic euglycaemic clamp. | Chronic (0 to 6 month) |
| Blood pressure and blood vessel regulation | Measurements taken of arterial stiffness, endothelial function and blood pressure. |
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Inclusion Criteria:
Exclusion Criteria:
NB: REC approved NoSA granted to include those on anti-hypertensives (29JUL2014)
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| Name | Affiliation | Role |
|---|---|---|
| Aedin Cassidy, PhD | University of East Anglia | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Harvard School of Public Health | Boston | Massachusetts | 02115 | United States | ||
| Addenbrooke's hospital |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 38432713 | Derived | 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. | |
| 34883305 |
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| ID | Term |
|---|---|
| D007333 | Insulin Resistance |
| D024821 | Metabolic Syndrome |
| ID | Term |
|---|---|
| D006946 | Hyperinsulinism |
| D044882 | Glucose Metabolism Disorders |
| D008659 | Metabolic Diseases |
| D009750 | Nutritional and Metabolic Diseases |
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|
| Half dose blueberry | 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 | 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. |
|
| Chronic (0 to 6 month) |
| Lung function | Assessed via standard spirometry techniques and biological assessment of exhaled samples. | Chronic (0 to 6 month) |
| Cognitive function | Assessed via a validated cognitive test battery. | Chronic (0 to 6 month) |
| Liver fat and blood flow assessment | Assessment via 3T MRI in a sub-group of participants. | Chronic (0 to 6 month) |
| Bio-availability | Flavonoid and metabolite levels will be assessed in blood and 24 hour urine samples. | Chronic (0 to 6 month) |
| Metabolite phenotype effects | The gut microbiome will be assessed from faecal sample collection and the impact on metabolism and of genotype, will be assessed via a targeted approach. | Chronic (0 to 6 month) |
| Acute +24 hour effect of single (26g) intervention intake, given with high fat challenge | Insulin resistance, lipaemia, vascular, cognitive and lung function measured pre- and post-intervention in combination with a high fat challenge in a sub-group of participants. Urine samples and blood samples (over a 24 hour period) will be taken for biomarker analysis. | Chronic (0 to 6 month) |
| Cambridge |
| Cambridgeshire |
| CB2 0QQ |
| United Kingdom |
| Norwich Medical School University of East Anglia | Norwich | Norfolk | NR4 7TJ | United Kingdom |
| Norfolk and Norwich University Hospital | Norwich | Norfolk | NR4 7UY | United Kingdom |
| Derived |
| 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. |
| 31136659 | Derived | 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. |