Trial reportEuropean journal of nutrition2012
A preliminary investigation of the impact of catechol-O-methyltransferase genotype on the absorption and metabolism of green tea catechins.
Trial report in European journal of nutrition, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
16 citing papers in PubMed, 1 synthesis or guideline pooled it.
- The impact of single nucleotide polymorphisms on the absorption, distribution, metabolism, and excretion of dietary (poly)phenols: a critical systematic review.Food & function · 2025Pooled it
- Enhanced bioavailability and short-term safety of a micellar green tea extract formulation co-delivered with N-acetylcysteine: a randomized crossover study in healthy adults.Frontiers in nutrition · 2026Trial
- Hepatotoxicity with High-Dose Green Tea Extract: Effect ofJournal of dietary supplements · 2023Trial
- Green Tea Catechin Extract Supplementation Does Not Influence Circulating Sex Hormones and Insulin-Like Growth Factor Axis Proteins in a Randomized Controlled Trial of Postmenopausal Women at High Risk of Breast Cancer.The Journal of nutrition · 2019Trial
- Population nutrikinetics of green tea extract.PloS one · 2018Trial
- Tea-induced improvement of endothelial function in humans: No role for epigallocatechin gallate (EGCG).Scientific reports · 2017Trial
- Trial
- Proanthocyanidins in immune-mediated inflammatory diseases: molecular mechanisms and therapeutic potential.Frontiers in pharmacology · 2026Review
- (-)-Epicatechin and inflammation: Unraveling the role of microbial metabolites and interindividual metabolic variability.Frontiers in microbiology · 2026Review
- Personalizing Dietary Polyphenols for Health Maintenance and Disease Management: A Nutrigenetic Approach.Current nutrition reports · 2025Review
- Perspective on the Coevolutionary Role of Host and Gut Microbiota in Polyphenol Health Effects: Metabotypes and Precision Health.Molecular nutrition & food research · 2024Review
- Epigallocatechin-3-Gallate Delivery in Lipid-Based Nanoparticles: Potentiality and Perspectives for Future Applications in Cancer Chemoprevention and Therapy.Frontiers in pharmacology · 2022Review
- Medicinal Herbs Used in Traditional Management of Breast Cancer: Mechanisms of Action.Medicines (Basel, Switzerland) · 2020Review
- Inhibitory Effect of Bovine Lactoferrin on Catechol-O-Methyltransferase.Molecules (Basel, Switzerland) · 2017Article
- Physicochemical properties of dietary phytochemicals can predict their passive absorption in the human small intestine.Scientific reports · 2017Article
- The catechol-Journal of functional foods · 2015Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
purposeGreen tea is thought to possess many beneficial effects on human health. However, the extent of green tea polyphenol biotransformation may affect its proposed therapeutic effects. Catechol-O-methyltransferase (COMT), the enzyme responsible for polyphenolic methylation, has a common polymorphism in the genetic code at position 158 reported to result in a 40% reduction in enzyme activity in in vitro studies. The current preliminary study was designed to investigate the impact of COMT genotype on green tea catechin absorption and metabolism in humans.
methodsTwenty participants (10 of each homozygous COMT genotype) were recruited, and plasma concentration profiles were produced for epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), epicatechin (EC) and 4'-O-methyl EGCG after 1.1 g of Sunphenon decaffeinated green tea extract (836 mg green tea catechins), with a meal given after 60 min.
resultsFor the entire group, EGCG, EGC, EC, ECG and 4'-O-methyl EGCG reached maximum concentrations of 1.09, 0.41, 0.33, 0.16 and 0.08 μM at 81.5, 98.5, 99.0, 85.5 and 96.5 min, respectively. Bimodal curves were observed for the non-gallated green tea catechins EGC and EC as opposed to single-peaked curves for the gallated green tea catechins EGCG and ECG. No significant parametric differences between COMT genotype groups were found.
conclusionsIn conclusion, the COMT Val(158/108)Met does not appear to have a dramatic influence on EGCG absorption and elimination. However, further pharmacokinetic research is needed to substantiate these findings.
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Identifiers
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.