PURPOSE: To investigate the influence of dietary proteins (casein, soy protein) and skimmed milk on the plasma kinetics of green tea (GT) catechins. METHODS: In a randomized cross-over design with one-week intervals, 24 healthy normal-weight women consumed a test drink containing 1.75 g GT extract with or without the addition of different proteins. Treatments were GT (control), GT with skimmed milk (GT + M), GT with caseinate (GT + CS), or GT with soy protein (GT + S). Venous blood samples were taken before and several times during a period of 4.5 h after consumption of the test drink. Plasma concentrations of catechins were analyzed by HPLC with electrochemical detection. RESULTS: Compared to control, consumption of GT with milk, caseinate, or soy protein significantly reduced the bioavailability (mean area under the plasma concentration-time curve) of total catechins (means ± SEM; GT + M, 87 ± 5%; GT + CS, 79 ± 5%; GT + S, 88 ± 4%), epigallocatechin gallate (GT + M, 68 ± 4%; GT + CS, 63 ± 5%; GT + S, 76 ± 5%), and epicatechin gallate (GT + M, 68 ± 5%; GT + CS, 66 ± 6%; GT + S, 77 ± 6%), while the bioavailability of non-galloylated catechins such as epigallocatechin (GT + M, 134 ± 9%; GT + CS, 118 ± 9 %; GT + S, 123 ± 8%) and epicatechin (GT + M, 125 ± 10%; GT + CS, 114 ± 11%; GT + S, 110 ± 8%) significantly increased. No significant differences in bioavailability of GT catechins were observed between the treatments GT + M, GT + CS, or GT + S. CONCLUSION: Simultaneous ingestion of dietary proteins reduces the bioavailability of galloylated catechins from GT in humans.
RCT Entities:
PURPOSE: To investigate the influence of dietary proteins (casein, soy protein) and skimmed milk on the plasma kinetics of green tea (GT) catechins. METHODS: In a randomized cross-over design with one-week intervals, 24 healthy normal-weight women consumed a test drink containing 1.75 g GT extract with or without the addition of different proteins. Treatments were GT (control), GT with skimmed milk (GT + M), GT with caseinate (GT + CS), or GT with soy protein (GT + S). Venous blood samples were taken before and several times during a period of 4.5 h after consumption of the test drink. Plasma concentrations of catechins were analyzed by HPLC with electrochemical detection. RESULTS: Compared to control, consumption of GT with milk, caseinate, or soy protein significantly reduced the bioavailability (mean area under the plasma concentration-time curve) of total catechins (means ± SEM; GT + M, 87 ± 5%; GT + CS, 79 ± 5%; GT + S, 88 ± 4%), epigallocatechin gallate (GT + M, 68 ± 4%; GT + CS, 63 ± 5%; GT + S, 76 ± 5%), and epicatechin gallate (GT + M, 68 ± 5%; GT + CS, 66 ± 6%; GT + S, 77 ± 6%), while the bioavailability of non-galloylated catechins such as epigallocatechin (GT + M, 134 ± 9%; GT + CS, 118 ± 9 %; GT + S, 123 ± 8%) and epicatechin (GT + M, 125 ± 10%; GT + CS, 114 ± 11%; GT + S, 110 ± 8%) significantly increased. No significant differences in bioavailability of GT catechins were observed between the treatments GT + M, GT + CS, or GT + S. CONCLUSION: Simultaneous ingestion of dietary proteins reduces the bioavailability of galloylated catechins from GT in humans.
Authors: Richard Draijer; Ferdi A van Dorsten; Yvonne E Zebregs; Boudewijn Hollebrands; Sonja Peters; Guus S Duchateau; Christian H Grün Journal: Nutrients Date: 2016-12-15 Impact factor: 5.717
Authors: Hellen A Oketch-Rabah; Amy L Roe; Cynthia V Rider; Herbert L Bonkovsky; Gabriel I Giancaspro; Victor Navarro; Mary F Paine; Joseph M Betz; Robin J Marles; Steven Casper; Bill Gurley; Scott A Jordan; Kan He; Mahendra P Kapoor; Theertham P Rao; Averell H Sherker; Robert J Fontana; Simona Rossi; Raj Vuppalanchi; Leonard B Seeff; Andrew Stolz; Jawad Ahmad; Christopher Koh; Jose Serrano; Tieraona Low Dog; Richard Ko Journal: Toxicol Rep Date: 2020-02-15