Acute effects of (–)-gallocatechin gallate-rich green tea extract on the cerebral hemodynamic response of the prefrontal cortex in healthy humans
DOI: 10.3389/fnrgo.2023.1136362
archive: archived pipeline: cataloged verified
Get this paper ↗ (DOI — opens at the source; we link to it, we don't host it)
Summary
This study investigates the acute effects of oral ingestion of (–)-gallocatechin gallate-rich green tea extract (GCG-GTE) on cerebral hemodynamics in the prefrontal cortex of healthy adults. While long-term green tea consumption is associated with cognitive benefits, the immediate impact of GCG, an epimer-type catechin with higher blood–brain barrier permeability than the more commonly studied EGCG, remains underexplored. The research aims to determine if a single dose of GCG-GTE alters task-dependent hemodynamic responses in the dorsolateral prefrontal cortex (DLPFC), a region critical for executive function and working memory. The researchers conducted a randomized, double-blind, placebo-controlled, parallel-group trial involving 35 healthy adults. Participants were assigned to receive either 900 mg of GCG-GTE or a placebo. One hour after ingestion, participants performed a battery of computerized cognitive tasks designed to demand prefrontal activation: mental arithmetic, the Corsi block-tapping task, and a verbal fluency task. Cerebral hemodynamic responses, specifically changes in oxy-hemoglobin (HbO2) concentration, were measured using functional near-infrared spectroscopy (fNIRS) with a 48-channel device positioned over the prefrontal cortex. Data were analyzed using mixed analyses of variance to assess group-by-session interactions in both behavioral performance and neural activation. The results revealed significant group-by-session interactions in fNIRS data for both the left (p = 0.035) and right (p = 0.036) DLPFC. Specifically, the GCG-GTE group exhibited reduced DLPFC activation during cognitively demanding tasks compared to the placebo group. In contrast, no significant differences were observed in behavioral cognitive performance measures between the two groups, although the GCG-GTE group showed a numerical increase in performance while the placebo group showed a slight decrease. Physiological measures, including heart rate and blood pressure, did not differ significantly between groups. The findings suggest that a single acute dose of GCG-GTE can reduce DLPFC activation in healthy humans during cognitively demanding tasks. This reduction in neural activity, despite maintained or slightly improved behavioral performance, indicates enhanced neural efficiency. The study concludes that GCG-GTE may lower mental workload by optimizing brain resource utilization during cognitive tasks. These results highlight GCG-GTE as a promising functional material for supporting cognitive health, though further research is required to confirm these acute effects and explore underlying mechanisms.
Provenance
The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed.
| Stage | Outcome | Tool | Model | Prompt | Attempts | Completed |
|---|---|---|---|---|---|---|
| discover | success | Crossref | — | — | 1 | 2026-08-09 |
| archive | success | canonical_url | — | — | 1 | 2026-08-09 |
| extract | success | cached | — | — | 3 | 2026-08-10 |
| clean | success | clean | — | — | 1 | 2026-08-09 |
| chunk | success | chunk | — | — | 1 | 2026-08-09 |
| embed | success | embed | Qwen/Qwen3-Embedding-8B | — | 1 | 2026-08-09 |
| promote | success | — | — | — | 1 | 2026-08-09 |
| summarize | success | llm | qwen3.6-27b-nvidia | summ-v5 | 2 | 2026-08-10 |
| tag | success | vector_similarity | — | — | 11 | 2026-08-11 |
| verify | success | — | — | — | 2 | 2026-08-10 |
Summary generated by qwen3.6-27b-nvidia on 2026-08-10; verification: verified.
Topics
Ranked by relevance to this paper. Hover a topic for its definition.