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| Name | Class |
|---|---|
| Radboud University Medical Center | OTHER |
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The study will explore the benefit of tea for microcirculation. Subjects will consume tea ar a placebo matched for taste and appearance in a blinded cross over design.
Epidemiological studies indicate that regular consumption of black tea reduces the risk of cardiovascular diseases. Tea consumption can result in improvements in endothelial function of conduit arteries as measured by flow mediated dilation.
Less is known however about its effects in other vascular beds. The study will test the hypothesis that tea affects endothelial function in the muscle microcirculation. This will be done by assessment of forearm blood flow using venous occlusion plethysmography after consumption of black tea against or placebo in a randomised, full cross-over study in 20 healthy middle-aged to elderly subjects
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Black tea | Experimental | Approximately 400 mg total polyphenols in 240 ml hot water (loading dose; 2 hours before the start of measurements; t=0) and 130 mg total polyphenols in 120 ml hot water (maintenance dose just before start of the measurements; t=120 min) |
|
| Placebo | Placebo Comparator | Caramel colour, maltodextrin and tea flavour in 240 ml hot water (2 hours before the start of measurements; t=0) and 120 ml hot water (maintenance dose just before start of the measurements; t=120 min) |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Tea | Other | Black tea infusion equivalent to approximately 530 mg total polyphenols expressed as gallic acid equivalents |
|
| Measure | Description | Time Frame |
|---|---|---|
| Forearm blood flow response to acetylcholine | Does tea ingestion change mean forearm blood flow response to acetylcholine when compared to placebo | During acetylcholine infusion 120-140 min after first tea/placebo intake |
| Measure | Description | Time Frame |
|---|---|---|
| Forearm blood flow response to sodium nitropusside | Does tea ingestion change mean forearm blood flow response to sodium nitropusside when compared to placebo | During sodium nitropusside infusion 170-190 min after first tea/placebo intake |
| Forearm blood flow response to L-NMMA |
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Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| Sean Roerink, Dr. | Radboud University Medical Center | Principal Investigator |
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| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 29460812 | Derived | Greyling A, Wolters TLC, de Bresser DM, Roerink SHPP, Riksen NP, Mulder TP, Rowson MJ, Hopman MT, Thijssen DHJ. The acute effect of black tea consumption on resistance artery endothelial function in healthy subjects. A randomized controlled trial. Clin Nutr ESPEN. 2018 Feb;23:41-47. doi: 10.1016/j.clnesp.2017.10.011. Epub 2017 Nov 8. |
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| ID | Term |
|---|---|
| D013662 | Tea |
| ID | Term |
|---|---|
| D028321 | Plant Preparations |
| D001688 | Biological Products |
| D045424 | Complex Mixtures |
| D001628 | Beverages |
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| Placebo | Other | Placebo matched to tea with respect to taste and appearance |
|
Does tea ingestion change mean forearm blood flow response to L-NG-monomethyl Arginine (L-NMMA) when compared to placebo |
| During L-NMMA infusion 220-240 min after first tea/placebo intake |
| D000066888 |
| Diet, Food, and Nutrition |
| D010829 | Physiological Phenomena |
| D019602 | Food and Beverages |