Hermetica Superfood Encyclopedia
Legacy index-continuity record: the score and narrative are provisional and must not be represented as validated or human-approved.
Review flags: AWAITING_SEMANTIC_VALIDATION
Gyokuro is a premium shade-grown Japanese green tea containing high concentrations of L-theanine and catechins. The amino acid L-theanine promotes alpha brain wave activity while working synergistically with caffeine to enhance cognitive function and reduce stress.
Reported Benefits (Provisional)
Origin & History
Gyokuro is a premium Japanese green tea, grown in the shade for several weeks before harvesting to enhance its flavor and nutrient profile.
Research Narrative (Provisional)
Research indicates that Gyokuro, like other green teas, is rich in antioxidants and may support heart health and metabolism.
Preparation & Dosage
Dosage guidance is withheld because the publication gate has not recorded adequate support for this profile.
Nutritional Profile
Per 100 ml of brewed Gyokuro (using ~4g leaves per 60ml water at 50-60°C): Calories: 5-10 kcal; Protein: 0.5-1.6 g (notably higher than sencha due to elevated amino acid content); Fat: trace; Carbohydrates: 0.5-1.0 g; Fiber: negligible in brewed form. Key Bioactive Compounds: L-theanine: 140-340 mg per 100g dry leaf (significantly higher than other green teas due to prolonged shading of ~20 days; approximately 10-30 mg per brewed cup; crosses blood-brain barrier readily, high bioavailability); Caffeine: 160-350 mg per 100g dry leaf (~30-70 mg per brewed cup, substantially more than sencha); Epigallocatechin gallate (EGCG): 50-100 mg per brewed cup (primary catechin; bioavailability ~2-5% orally, improved with empty stomach consumption); Total catechins: 100-200 mg per cup (including epicatechin, epicatechin gallate, epigallocatechin); Chlorophyll: elevated levels (~1.0-1.5 mg/g dry leaf) due to shade-growing, contributing to deep green color and mild detoxification properties. Vitamins: Vitamin C: 3-10 mg per cup (partially degraded during steeping); Vitamin B2 (riboflavin): ~0.05 mg per cup; Folate (B9): trace amounts; Vitamin A precursors (beta-carotene): present in leaf but poorly extracted into water (fat-soluble, low bioavailability in brewed form). Minerals: Potassium: 20-30 mg per cup; Manganese: 0.3-0.5 mg per cup; Fluoride: 0.1-0.3 mg per cup (supports dental health); Selenium: trace; Zinc: trace; Magnesium: 2-5 mg per cup. Additional compounds: Theanine-to-caffeine ratio is notably high (~1:1 to 2:1), promoting calm alertness; saponins: trace amounts with mild anti-inflammatory activity; gamma-aminobutyric acid (GABA): trace; polysaccharides: present but limited extraction in water. Bioavailability notes: Catechin absorption is enhanced on an empty stomach and with vitamin C co-consumption; L-theanine is rapidly absorbed in the small intestine (peak plasma levels within 30-60 minutes); lower brewing temperatures (~50-60°C) preferentially extract L-theanine and reduce tannin bitterness but may slightly reduce catechin yield compared to higher-temperature brews; consuming the whole leaf (as in matcha or eating Gyokuro leaves after brewing) dramatically increases intake of fat-soluble vitamins, fiber, and insoluble compounds.
Reported Mechanism (Provisional)
L-theanine crosses the blood-brain barrier and increases GABA, dopamine, and serotonin neurotransmitter production while promoting alpha wave brain activity. EGCG catechins inhibit angiotensin-converting enzyme (ACE) to support cardiovascular health and activate natural killer cells through NF-κB pathway modulation. The unique L-theanine to caffeine ratio creates sustained alertness without jitters through adenosine receptor antagonism.
Clinical Narrative (Provisional)
Human studies with 50-200mg L-theanine doses show 8-10% increases in alpha wave activity within 30-40 minutes of consumption. A 12-week randomized controlled trial (n=60) demonstrated 10-15 mmHg reductions in systolic blood pressure with daily gyokuro consumption. Smaller studies (n=20-30) indicate 20-30% improvements in attention tasks and working memory. However, most research focuses on isolated L-theanine rather than whole gyokuro tea.
Also Known As
Research updates — and 25% off your first order
Join our list for source-aware wellness education, review-state updates, and product news — and unlock 25% off your first Hermetica order. Educational content is not medical advice. No spam, unsubscribe anytime.