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Human studies on the absorption, distribution, metabolism, and excretion of tea polyphenols.
Am J Clin Nutr. 2013 Dec; 98(6 Suppl):1619S-1630S.AJ

Abstract

Recent research on the bioavailability of flavan-3-ols after ingestion of green tea by humans is reviewed. Glucuronide, sulfate, and methyl metabolites of (epi)catechin and (epi)gallocatechin glucuronide reach peak nanomolar per liter plasma concentrations 1.6-2.3 h after intake, indicating absorption in the small intestine. The concentrations then decline, and only trace amounts remain 8 h after ingestion. Urinary excretion of metabolites over a 24-h period after green tea consumption corresponded to 28.5% of the ingested (epi)catechin and 11.4% of (epi)gallocatechin, suggesting higher absorption than that of most other flavonoids. The fate of (-)-epicatechin-3-O-gallate, the main flavan-3-ol in green tea, is unclear because it appears unmetabolized in low concentrations in plasma but is not excreted in urine. Possible enterohepatic recirculation of flavan-3-ols is discussed along with the impact of dose and other food components on flavan-3-ol bioavailability. Approximately two-thirds of the ingested flavan-3-ols pass from the small to the large intestine where the action of the microbiota results in their conversion to C-6-C-5 phenylvalerolactones and phenylvaleric acids, which undergo side-chain shortening to produce C-6-C-1 phenolic and aromatic acids that enter the bloodstream and are excreted in urine in amounts equivalent to 36% of flavan-3-ol intake. Some of these colon-derived catabolites may have a role in vivo in the potential protective effects of tea consumption. Although black tea, which contains theaflavins and thearubigins, is widely consumed in the Western world, there is surprisingly little research on the absorption and metabolism of these compounds after ingestion and their potential impact on health.

Authors+Show Affiliations

Department of Nutritional Sciences, University of Surrey, Guildford, Surrey, United Kingdom (MNC); and the School of Medicine, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom (JJJvdH and AC).No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Review

Language

eng

PubMed ID

24172307

Citation

Clifford, Michael N., et al. "Human Studies On the Absorption, Distribution, Metabolism, and Excretion of Tea Polyphenols." The American Journal of Clinical Nutrition, vol. 98, no. 6 Suppl, 2013, 1619S-1630S.
Clifford MN, van der Hooft JJ, Crozier A. Human studies on the absorption, distribution, metabolism, and excretion of tea polyphenols. Am J Clin Nutr. 2013;98(6 Suppl):1619S-1630S.
Clifford, M. N., van der Hooft, J. J., & Crozier, A. (2013). Human studies on the absorption, distribution, metabolism, and excretion of tea polyphenols. The American Journal of Clinical Nutrition, 98(6 Suppl), 1619S-1630S. https://doi.org/10.3945/ajcn.113.058958
Clifford MN, van der Hooft JJ, Crozier A. Human Studies On the Absorption, Distribution, Metabolism, and Excretion of Tea Polyphenols. Am J Clin Nutr. 2013;98(6 Suppl):1619S-1630S. PubMed PMID: 24172307.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Human studies on the absorption, distribution, metabolism, and excretion of tea polyphenols. AU - Clifford,Michael N, AU - van der Hooft,Justin J J, AU - Crozier,Alan, Y1 - 2013/10/30/ PY - 2013/11/1/entrez PY - 2013/11/1/pubmed PY - 2014/3/14/medline SP - 1619S EP - 1630S JF - The American journal of clinical nutrition JO - Am J Clin Nutr VL - 98 IS - 6 Suppl N2 - Recent research on the bioavailability of flavan-3-ols after ingestion of green tea by humans is reviewed. Glucuronide, sulfate, and methyl metabolites of (epi)catechin and (epi)gallocatechin glucuronide reach peak nanomolar per liter plasma concentrations 1.6-2.3 h after intake, indicating absorption in the small intestine. The concentrations then decline, and only trace amounts remain 8 h after ingestion. Urinary excretion of metabolites over a 24-h period after green tea consumption corresponded to 28.5% of the ingested (epi)catechin and 11.4% of (epi)gallocatechin, suggesting higher absorption than that of most other flavonoids. The fate of (-)-epicatechin-3-O-gallate, the main flavan-3-ol in green tea, is unclear because it appears unmetabolized in low concentrations in plasma but is not excreted in urine. Possible enterohepatic recirculation of flavan-3-ols is discussed along with the impact of dose and other food components on flavan-3-ol bioavailability. Approximately two-thirds of the ingested flavan-3-ols pass from the small to the large intestine where the action of the microbiota results in their conversion to C-6-C-5 phenylvalerolactones and phenylvaleric acids, which undergo side-chain shortening to produce C-6-C-1 phenolic and aromatic acids that enter the bloodstream and are excreted in urine in amounts equivalent to 36% of flavan-3-ol intake. Some of these colon-derived catabolites may have a role in vivo in the potential protective effects of tea consumption. Although black tea, which contains theaflavins and thearubigins, is widely consumed in the Western world, there is surprisingly little research on the absorption and metabolism of these compounds after ingestion and their potential impact on health. SN - 1938-3207 UR - https://www.unboundmedicine.com/medline/citation/24172307/Human_studies_on_the_absorption_distribution_metabolism_and_excretion_of_tea_polyphenols_ L2 - https://academic.oup.com/ajcn/article-lookup/doi/10.3945/ajcn.113.058958 DB - PRIME DP - Unbound Medicine ER -