Sindhu Kashyap1, Nirupama Shivakumar2, Aneesia Varkey1, Thomas Preston3, Sarita Devi1, Anura V Kurpad1,2. 1. Division of Nutrition, St. John's Research Institute. 2. Department of Physiology, St. John's Medical College, St. John's National Academy of Health Sciences, Bangalore, India. 3. Scottish Universities Environmental Research Centre, East Kilbride, Scotland, United Kingdom.
Abstract
BACKGROUND: Tea, a commonly consumed beverage, contains high amounts of polyphenols that can impair protein digestibility, as demonstrated in vitro. There are no human studies examining the inhibitory influence of tea polyphenols (TPP) on high-quality protein digestibility. OBJECTIVE: The aim of this study was to determine the effect of black tea on the true indispensable amino acid (IAA) digestibility of whole boiled egg protein, in healthy adult humans, through use of a dual isotope tracer approach. METHODS: The effect of black TPP (4.6 mg/mL, ingested as a beverage with the meal) on 2H-labeled whole boiled egg protein, administered with ghee rice and tomato curry, was measured with reference to 13C-spirulina protein in healthy Indian adults aged 20-27 y of both sexes with BMI of 22.0 ± 2.8 kg/m2. The results were then compared to previously determined whole egg mean IAA digestibility measured by the same method, without black tea, in the same subjects (n = 5). To correct for any independent effect of TPP on spirulina protein (used as a standard protein), the true IAA digestibility of 13C-spirulina protein was independently measured with reference to a 2H-amino acid mixture, with and without co-ingestion of black tea, in 3 of the same subjects. RESULTS: The true IAA digestibility of whole boiled egg protein significantly decreased by 17% when co-ingested with black tea. However, there was no significant reduction in the true IAA digestibility of spirulina protein when co-ingested with black tea. CONCLUSIONS: TPP protein interactions reduced whole egg digestibility in healthy Indian adults but had minimal effect on spirulina protein digestibility. In populations who are at risk of dietary quality protein inadequacy, the consumption of tea during or after a meal can further increase the risk of inadequacy. This trial was registered at Clinical Trials Registry of India (http://ctri.nic.in) as CTRI/2018/03/012265.
BACKGROUND: Tea, a commonly consumed beverage, contains high amounts of polyphenols that can impair protein digestibility, as demonstrated in vitro. There are no human studies examining the inhibitory influence of tea polyphenols (TPP) on high-quality protein digestibility. OBJECTIVE: The aim of this study was to determine the effect of black tea on the true indispensable amino acid (IAA) digestibility of whole boiled egg protein, in healthy adult humans, through use of a dual isotope tracer approach. METHODS: The effect of black TPP (4.6 mg/mL, ingested as a beverage with the meal) on 2H-labeled whole boiled egg protein, administered with ghee rice and tomato curry, was measured with reference to 13C-spirulina protein in healthy Indian adults aged 20-27 y of both sexes with BMI of 22.0 ± 2.8 kg/m2. The results were then compared to previously determined whole egg mean IAA digestibility measured by the same method, without black tea, in the same subjects (n = 5). To correct for any independent effect of TPP on spirulina protein (used as a standard protein), the true IAA digestibility of 13C-spirulina protein was independently measured with reference to a 2H-amino acid mixture, with and without co-ingestion of black tea, in 3 of the same subjects. RESULTS: The true IAA digestibility of whole boiled egg protein significantly decreased by 17% when co-ingested with black tea. However, there was no significant reduction in the true IAA digestibility of spirulina protein when co-ingested with black tea. CONCLUSIONS: TPP protein interactions reduced whole egg digestibility in healthy Indian adults but had minimal effect on spirulina protein digestibility. In populations who are at risk of dietary quality protein inadequacy, the consumption of tea during or after a meal can further increase the risk of inadequacy. This trial was registered at Clinical Trials Registry of India (http://ctri.nic.in) as CTRI/2018/03/012265.
Authors: Anura V Kurpad; Meredith M Regan; Dilip Nazareth; Savita Nagaraj; Justin Gnanou; Vernon R Young Journal: Am J Clin Nutr Date: 2003-12 Impact factor: 7.045
Authors: Joseph A Rothwell; Jara Perez-Jimenez; Vanessa Neveu; Alexander Medina-Remón; Nouha M'hiri; Paula García-Lobato; Claudine Manach; Craig Knox; Roman Eisner; David S Wishart; Augustin Scalbert Journal: Database (Oxford) Date: 2013-10-07 Impact factor: 3.451
Authors: Nikkie van der Wielen; Nadezda V Khodorova; Walter J J Gerrits; Claire Gaudichon; Juliane Calvez; Daniel Tomé; Marco Mensink Journal: J Nutr Date: 2020-09-01 Impact factor: 4.798