Bolus ingestion of white and green tea increases the concentration of several flavan‐3‐ols in plasma,but does not affect markers of oxidative stress in healthy non‐smokers |
| |
Authors: | Nadine Müller Sabine Ellinger Birgit Alteheld Gudrun Ulrich‐Merzenich Heiner K Berthold Hans Vetter Peter Stehle |
| |
Affiliation: | 1. Department of Nutrition and Food Science – Nutritional Physiology, University of Bonn, Bonn, Germany;2. These authors have contributed equally to this study and could be considered as co‐first authors.;3. Medical Policlinic, University Hospital Bonn, Bonn, Germany;4. Lipid Clinic at the Interdisciplinary Metabolism Center, Virchow Clinic Campus, Charité University Medicine Berlin, Berlin, Germany |
| |
Abstract: | White tea (WT) is rich in flavan‐3‐ols as green tea (GT) and might provide health protective effects due to the strong antioxidant properties of flavan‐3‐ols. Since intervention studies with WT are lacking, we evaluated the effects of WT consumption on antioxidant status, antioxidant capacity and biomarkers of oxidative stress compared to water and GT. After an overnight fast, 70 healthy non‐smokers were randomized to consume 600 mL of WT, GT or water (control). Plasma (epi‐)catechin and epi(gallo)catechingallate, antioxidant capacity (Folin assay, trolox equivalent antioxidant capacity test), 8‐iso‐prostaglandin F2α, ascorbic acid and uric acid were determined before and several times within 8 h after consumption. DNA strand breaks were measured in vivo and ex vivo (H2O2 stimulation) in leukocytes. Plasma flavan‐3‐ols significantly increased after WT and GT ingestion. Trolox equivalent antioxidant capacity was lower after 5 h in controls versus WT (p=0.031) and GT (p=0.005). Folin‐Ciocalteu reducing capacity, ascorbic and uric acid as well as markers of oxidative stress (8‐iso‐prostaglandin‐F2α, DNA strand breaks) were not affected by the beverages. A short‐term increase of catechins does not change plasma antioxidant capacity in healthy subjects. Conclusions with respect to health protective effects of WT and GT on the basis of these biomarkers can, thus, not be drawn. |
| |
Keywords: | Antioxidant capacity Bolus ingestion Green tea Oxidative stress White tea |
|
|