# Camellia sinensis 'Samidori'

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/camellia-sinensis-samidori
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-04-01
**Evidence Score:** 2 / 10
**Category:** Tea Cultivars
**Also Known As:** Samidori cultivar, Samidori tea, Camellia sinensis var. Samidori, Samidori green tea cultivar, Uji Samidori

## Overview

Camellia sinensis 'Samidori' is a Japanese shaded green tea cultivar selectively bred for elevated L-theanine and chlorophyll content, particularly used in high-grade matcha production. The shading process, typically applied 20–30 days before harvest, suppresses photosynthesis-driven catechin accumulation while amplifying theanine biosynthesis via root-to-leaf transport of glutamate precursors.

## Health Benefits

• No specific health benefits have been clinically studied for the 'Samidori' cultivar - evidence quality: absent
• General green tea benefits may apply but are not cultivar-specific - evidence quality: not established for this variant
• Enhanced theanine content from shading may support relaxation, though not quantified for 'Samidori' - evidence quality: theoretical only
• Low tannin/catechin content results in minimal bitterness but health implications unstudied - evidence quality: no data
• Traditional use suggests quality tea experience but no health claims validated - evidence quality: traditional use only

## Mechanism of Action

L-theanine, concentrated in shade-grown 'Samidori' leaves, crosses the blood-brain barrier and modulates AMPA, NMDA, and kainate glutamate receptors while increasing GABA and [dopamine](/ingredients/condition/mood) synthesis, promoting alpha-wave cortical activity. Residual epigallocatechin gallate (EGCG) inhibits catechol-O-methyltransferase (COMT) and modulates NF-κB [inflammatory](/ingredients/condition/inflammation) signaling pathways. Caffeine present in the leaf acts synergistically with theanine by blocking adenosine A1 and A2A receptors, producing attentive calm without pronounced sympathetic stimulation.

## Clinical Summary

No randomized controlled trials have been conducted specifically on the 'Samidori' cultivar; available evidence is extrapolated from broader green tea and shade-grown matcha research. Studies on L-theanine (100–200 mg doses) in general green tea populations demonstrate modest but significant reductions in perceived stress and improvements in attention accuracy, notably in a 2008 double-blind crossover trial (n=16) by Gomez-Ramirez et al. EGCG research at doses of 400–800 mg/day shows [antioxidant](/ingredients/condition/antioxidant) and modest metabolic effects in humans, but shading reduces catechin levels in cultivars like 'Samidori', making direct catechin-based benefits less applicable. Overall evidence quality for cultivar-specific claims remains absent, and benefits attributed to 'Samidori' are inferred from mechanistic and compositional data rather than clinical trials.

## Nutritional Profile

Camellia sinensis 'Samidori' is a shaded green tea cultivar (used primarily for matcha and gyokuro-style teas), and its nutritional profile reflects both its genetic characteristics and cultivation method. Per 1g of powdered leaf (matcha preparation): Protein: ~0.3g (tea proteins including theanine-rich fractions); the whole-leaf consumption format increases protein bioavailability compared to steeped teas. L-Theanine: estimated 2.5–4.5mg per gram of leaf, elevated above unshaded cultivars due to shading-induced suppression of theanine-to-catechin conversion; shading typically increases theanine by 20–50% compared to sun-grown equivalents. Catechins (total): estimated 80–120mg/g dry leaf weight, lower than high-catechin cultivars like Yabukita due to cultivar genetics and shading — EGCG (epigallocatechin gallate): ~40–60mg/g; EGC: ~10–20mg/g; ECG and EC present in smaller fractions. Caffeine: approximately 25–35mg/g dry leaf, comparable to other shaded cultivars. Chlorophyll: elevated (~3–5mg/g) relative to unshaded teas due to shading-induced upregulation; responsible for characteristic deep green color. Vitamins: Vitamin C (~1–3mg/g, partially degraded in processing); Vitamin K1 (~20–30µg/g); Vitamin E (tocopherols, ~0.5–1mg/g). Minerals: Potassium (~20mg/g), Calcium (~3–5mg/g), Magnesium (~2–3mg/g), Fluoride (~0.1–0.3mg/g), Manganese (~0.3–0.5mg/g). Fiber: ~3–5mg/g soluble fiber (when consumed as whole-leaf matcha). Bioavailability notes: Whole-leaf matcha consumption delivers significantly higher bioavailability of catechins, theanine, and fat-soluble compounds (chlorophyll, Vitamin K, Vitamin E) compared to steeped preparations where 70–90% of catechins remain in spent leaves. Theanine is highly water-soluble and well-absorbed (>80%). Catechin bioavailability is moderate (~5–10% systemic absorption) and improved by consuming with food. All concentrations are estimates extrapolated from shaded Japanese green tea cultivar data; cultivar-specific analytical data for 'Samidori' is not independently published in peer-reviewed literature.

## Dosage & Preparation

No clinically studied dosage ranges exist for 'Samidori'. Traditional consumption as matcha involves 1-2g of powder per serving, though no standardization for catechins or theanine content is specified for this cultivar. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Consumed as a beverage or matcha powder at typical culinary doses, 'Samidori'-derived green tea is generally recognized as safe; adverse effects at high supplemental doses include nausea, [insomnia](/ingredients/condition/sleep), and elevated liver enzymes reported with concentrated EGCG extracts above 800 mg/day. Caffeine content (approximately 30–70 mg per 8 oz serving) warrants caution in individuals sensitive to stimulants, those with cardiac arrhythmias, or patients taking MAO inhibitors. EGCG can inhibit the absorption of iron from non-heme sources and may interact with anticoagulants such as warfarin by exhibiting mild antiplatelet activity. Pregnant individuals should limit total caffeine intake to under 200 mg/day per WHO guidance, and high-dose green tea extracts are not recommended during pregnancy due to folate absorption interference.

## Scientific Research

No human clinical trials, RCTs, or meta-analyses specifically on Camellia sinensis 'Samidori' were identified in available sources. While general Camellia sinensis studies exist for metabolic health, no cultivar-specific data or PMIDs are available for this particular variant.

## Historical & Cultural Context

'Samidori' holds a unique place in Japanese tea tradition from Uji, the cultural heart of matcha production. It is prized for ceremonial matcha and gyokuro production due to its umami flavor, creaminess, and low astringency. The cultivar symbolizes excellence in Japanese tea craftsmanship alongside other premium cultivars like Yabukita.

## Synergistic Combinations

L-theanine, EGCG, vitamin C, quercetin, zinc

## Frequently Asked Questions

### What makes Samidori different from other green tea cultivars?

'Samidori' is a Japanese cultivar developed by the National Tea Research Station, specifically prized for its bright green color, mild umami flavor, and higher-than-average L-theanine concentrations resulting from traditional shading (tana or direct shading) applied 20–30 days pre-harvest. Shading suppresses catechin synthesis while redirecting nitrogen metabolism toward theanine accumulation, producing a leaf chemically distinct from unshaded cultivars like Yabukita. This makes 'Samidori' particularly sought for premium matcha and gyokuro production rather than standard sencha.

### How much L-theanine is in Samidori matcha?

Shade-grown 'Samidori' leaves used for matcha can contain approximately 2–4% dry-weight L-theanine, compared to roughly 1–2% in unshaded green tea cultivars, though exact concentrations vary by shading duration, harvest season, and processing method. A standard 2-gram serving of matcha powder may deliver 40–80 mg of L-theanine, placing it near the lower end of doses (100–200 mg) studied in clinical relaxation research. Consumers seeking theanine for specific therapeutic purposes often supplement with standardized capsules to achieve consistent, studied dosages.

### Does Samidori green tea help with anxiety or relaxation?

No clinical trials have tested 'Samidori' specifically for anxiety outcomes; however, its elevated L-theanine content provides a mechanistic basis for relaxation effects. L-theanine at 100–200 mg doses has demonstrated statistically significant reductions in salivary cortisol and self-reported stress in small human trials, and EEG studies confirm increased alpha-wave activity within 30–60 minutes of ingestion. The effect is described as relaxed alertness rather than sedation, particularly when theanine is co-ingested with caffeine, as naturally occurs in green tea.

### Is Samidori matcha safe to drink every day?

Daily consumption of 1–3 servings of 'Samidori'-based matcha is considered safe for most healthy adults, providing roughly 60–200 mg caffeine and 40–150 mg L-theanine per day within generally tolerated ranges. Individuals with liver conditions should avoid high-dose concentrated matcha or green tea extract supplements, as EGCG above 800 mg/day has been associated with hepatotoxicity in case reports. Those on blood thinners, iron-deficiency protocols, or stimulant-sensitive medications should consult a healthcare provider before regular high-volume consumption.

### How does shading affect the EGCG content in Samidori tea?

Shading significantly reduces photosynthetic activity in 'Samidori' leaves, which in turn suppresses the UV-driven biosynthesis of catechins including epigallocatechin gallate (EGCG) — the primary antioxidant polyphenol in green tea. Studies on shaded versus unshaded tea show catechin reductions of 30–50% in shaded leaves, meaning shade-grown 'Samidori' matcha delivers substantially less EGCG per gram than unshaded sencha from the same or comparable cultivars. This trade-off is intentional: lower astringency and higher theanine are prioritized over maximum catechin antioxidant capacity in premium shaded tea production.

### Is Samidori matcha safe during pregnancy and breastfeeding?

While green tea is generally considered safe in moderate amounts during pregnancy, the caffeine content in Samidori matcha (approximately 25-70 mg per serving) should be discussed with a healthcare provider, as caffeine intake is typically limited during pregnancy. Breastfeeding mothers should also consult their doctor, as caffeine passes into breast milk. No specific safety data exists for the Samidori cultivar in these populations, so individualized medical guidance is recommended.

### Does Samidori matcha interact with blood pressure or heart medications?

Samidori matcha contains caffeine and catechins that may have mild cardiovascular effects, potentially interacting with blood pressure medications or beta-blockers in sensitive individuals. If you take medications for hypertension, arrhythmia, or heart conditions, consult your healthcare provider before regular Samidori consumption. No cultivar-specific interaction studies exist, so professional medical review of your personal medication profile is essential.

### How does the brewing method affect the nutrient profile of Samidori matcha?

Water temperature and brewing time significantly impact L-theanine extraction and chlorophyll retention in Samidori matcha—lower temperatures (around 160-180°F) and shorter steeping times preserve more of the delicate amino acids compared to hotter water. Since Samidori is a shade-grown cultivar optimized for premium preparation, traditional whisking methods with stone-ground powder maximize bioavailability of its compounds. Proper preparation preserves the cultivar's enhanced theanine-to-caffeine ratio better than standard steeping.

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