# Jin Xuan Oolong (Camellia sinensis)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/jin-xuan-oolong
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-24
**Evidence Score:** 2 / 10
**Category:** Tea
**Also Known As:** Camellia sinensis var. Jin Xuan, Milk Oolong, TRES No. 12, 台茶十二號, Nai Xiang, Creamy Oolong, Taiwan Oolong No. 12

## Overview

Jin Xuan Oolong is a Taiwanese cultivar of Camellia sinensis containing polyphenols such as EGCG (epigallocatechin gallate), theaflavins, and thearubigins that exert antioxidant effects via [free radical scaveng](/ingredients/condition/antioxidant)ing and inhibition of lipid peroxidation. No human clinical trials have been conducted specifically on this cultivar, so its benefits are extrapolated from broader oolong and green tea research.

## Health Benefits

• No clinical evidence available - no human trials specific to Jin Xuan Oolong have been conducted
• General oolong tea benefits exist but are not cultivar-specific (evidence quality: not applicable)
• Contains typical tea polyphenols like catechins and EGCG, but levels are unquantified (evidence quality: theoretical only)
• Traditional use limited as this is a modern 1980s cultivar without historical medicinal applications (evidence quality: none)
• May share general Camellia sinensis properties, but no Jin Xuan-specific research exists (evidence quality: extrapolated)

## Mechanism of Action

The catechins in Jin Xuan Oolong, primarily EGCG, inhibit catechol-O-methyltransferase (COMT) and modulate the PI3K/Akt signaling pathway, potentially influencing cellular proliferation and [oxidative stress](/ingredients/condition/antioxidant) responses. Theaflavins formed during partial oxidation can inhibit NF-κB activation, reducing [pro-inflammatory cytokine](/ingredients/condition/inflammation) transcription. Caffeine present in the leaf acts as an adenosine receptor antagonist (A1 and A2A), contributing to mild stimulant and thermogenic effects.

## Clinical Summary

No randomized controlled trials or observational studies have been conducted specifically on Jin Xuan Oolong as a distinct cultivar, making cultivar-specific efficacy claims unsupported by direct evidence. Broader oolong tea research, such as a 2003 study in the Archives of Dermatology (n=118), found significant atopic dermatitis symptom reduction after 4 weeks of daily consumption, though this used unspecified oolong varieties. Meta-analyses on green and oolong teas suggest modest reductions in [LDL cholesterol](/ingredients/condition/heart-health) (approximately 2–5 mg/dL) and fasting [blood glucose](/ingredients/condition/weight-management), but these effects cannot be reliably attributed to Jin Xuan specifically. Overall, the evidence quality for Jin Xuan Oolong as a distinct therapeutic agent is not applicable, and any benefits remain extrapolated from general Camellia sinensis research.

## Nutritional Profile

Jin Xuan Oolong (Camellia sinensis cv. TRES #12) is consumed as an infused beverage, so nutritional content reflects what leaches into the brew rather than the leaf itself. Per 240ml brewed cup (2g dry leaf, 85°C, 3-min steep): Calories ~2-4 kcal, Protein ~0.1g (minimal leached amino acids), Carbohydrates ~0.5-0.7g, Fat ~0g, Fiber ~0g (insoluble fiber remains in leaf). Key bioactive compounds: Caffeine 20-40mg per cup (moderate for oolong; lower oxidation than black tea but higher than green; Jin Xuan tends toward lighter oxidation at 15-40%, placing caffeine on lower end). L-theanine ~6-10mg per cup (promotes calm alertness; synergistic with caffeine; bioavailability ~87% oral absorption). Catechins (EGCG, EGC, ECG, EC) estimated 50-100mg total per cup — lower than green tea due to partial oxidation converting catechins to theaflavins and thearubigins, which are present at 10-30mg per cup. Chlorogenic acids ~5-15mg per cup. Gallic acid ~2-5mg per cup. Quercetin and kaempferol glycosides ~1-3mg per cup. Fluoride ~0.1-0.3mg per cup (naturally occurring; bioavailable). Manganese ~0.4-0.7mg per cup (~20-35% DV; one of tea's most concentrated minerals). Potassium ~35-60mg per cup. Magnesium ~5-10mg per cup. Zinc trace (~0.05mg). Vitamin K2 trace amounts (negligible). The characteristic milky/creamy aroma of Jin Xuan is attributed to the lactone compound nerolidol and a high concentration of (Z)-3-hexenyl hexanoate and linalool oxide, which are volatile aromatic compounds with no caloric contribution but potential mild anxiolytic properties theorized in vitro. Polyphenol bioavailability is moderate; co-consumption with milk reduces catechin absorption by ~25%. Drinking on an empty stomach increases absorption but may cause gastric irritation.

## Dosage & Preparation

No clinically studied dosages exist for Jin Xuan Oolong. Traditional infusion uses 3-5g of leaves per 200-250mL water at 80°C for 3 minutes, repeatable 3-4 times. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Jin Xuan Oolong contains caffeine (estimated 30–50 mg per 8 oz serving, typical for oolong), which may cause [insomnia](/ingredients/condition/sleep), tachycardia, or anxiety in sensitive individuals or at high intake. EGCG can inhibit the enzyme CYP3A4 and may interact with medications including warfarin, statins, and certain chemotherapy agents, potentially altering drug plasma concentrations. High daily polyphenol intake from multiple servings may reduce non-heme iron absorption by up to 75% when consumed with meals, posing a risk for individuals with iron-deficiency anemia. Pregnant individuals are advised to limit caffeine intake to under 200 mg per day, and concentrated tea extracts are not recommended during pregnancy due to insufficient safety data.

## Scientific Research

No human clinical trials, RCTs, or meta-analyses specifically on Jin Xuan Oolong (Camellia sinensis cultivar No. 12) were identified in PubMed records. While general oolong tea studies exist for weight loss and [cardiovascular](/ingredients/condition/heart-health) effects, none distinguish this specific cultivar from others.

## Historical & Cultural Context

Jin Xuan lacks historical traditional medicine use, as it is a modern cultivar bred in Taiwan in the early 1980s for commercial oolong production. While oolong teas generally trace to Chinese Fujian province origins used for [digestion](/ingredients/condition/gut-health) and vitality in TCM for centuries, Jin Xuan has no unique traditional roles.

## Synergistic Combinations

Green tea extract, L-theanine, matcha powder, gyokuro tea, sencha extract

## Frequently Asked Questions

### Does Jin Xuan Oolong have more EGCG than other oolong teas?

No published comparative analysis has quantified EGCG levels specifically in Jin Xuan Oolong versus other oolong cultivars. Oolong teas generally contain less EGCG than green teas due to partial oxidation, which converts catechins into theaflavins and thearubigins. Without cultivar-specific laboratory data, no claim that Jin Xuan is higher or lower in EGCG than other oolong varieties can be substantiated.

### Can Jin Xuan Oolong help with weight loss?

Weight loss effects have not been studied in clinical trials specific to Jin Xuan Oolong. General oolong tea research suggests caffeine and EGCG may modestly increase energy expenditure by approximately 3–4% over 24 hours by upregulating norepinephrine-mediated thermogenesis, according to small metabolic studies. These effects are modest, cultivar non-specific, and insufficient to substitute for dietary or lifestyle interventions.

### How much caffeine is in Jin Xuan Oolong tea?

Jin Xuan Oolong has not been independently analyzed for caffeine content in published literature, but typical oolong teas contain approximately 30–50 mg of caffeine per 8-ounce brewed cup, compared to 70–140 mg in coffee. Caffeine content varies significantly based on water temperature, steep time, leaf-to-water ratio, and harvest season. Individuals sensitive to caffeine should limit consumption and avoid drinking it close to bedtime.

### Is Jin Xuan Oolong safe to drink every day?

For most healthy adults, drinking 1–3 cups of Jin Xuan Oolong daily is considered safe, consistent with general guidance on moderate tea consumption from bodies like the European Food Safety Authority. Daily high-volume consumption (more than 5–6 cups) may increase fluoride intake, elevate caffeine exposure above 400 mg/day, and reduce iron absorption due to polyphenol binding. Individuals on anticoagulants like warfarin should consult a healthcare provider, as tea polyphenols may affect vitamin K metabolism and drug efficacy.

### What makes Jin Xuan Oolong different from other oolong teas?

Jin Xuan is a specific tea cultivar (TRES No. 12) developed by the Taiwan Tea Research and Extension Station in 1981, distinguished by its naturally creamy or milky aroma attributed to volatile compounds including nerolidol and indole produced during specific growing conditions. It is partially oxidized like all oolong teas, placing its polyphenol and catechin profile between green and black tea. However, no peer-reviewed studies have compared its phytochemical composition or health effects to other oolong cultivars such as Dong Ding or Tie Guan Yin.

### Is Jin Xuan Oolong safe during pregnancy and breastfeeding?

Jin Xuan Oolong contains caffeine (approximately 30–50 mg per 8 oz cup), which pregnancy and lactation guidelines generally recommend limiting to under 200 mg daily; moderate consumption is typically considered acceptable but should be discussed with a healthcare provider. Since no clinical safety studies exist specifically for this cultivar during pregnancy or breastfeeding, the safety profile relies on general oolong tea data rather than cultivar-specific evidence. Pregnant or nursing women should consult their doctor before regular consumption.

### Does Jin Xuan Oolong interact with medications?

Jin Xuan Oolong's caffeine and polyphenol content may theoretically interact with certain medications—particularly blood thinners, stimulant drugs, and medications sensitive to caffeine—though no cultivar-specific interaction studies exist. The catechins in oolong tea can potentially affect iron absorption if consumed with iron supplements or medications, though the clinical significance varies. Anyone taking regular medications should consult their healthcare provider before making Jin Xuan Oolong a daily habit.

### How should Jin Xuan Oolong tea be brewed to preserve its beneficial compounds?

Jin Xuan Oolong is traditionally steeped at 195–205°F (90–96°C) for 3–5 minutes, with multiple infusions possible from the same leaves; higher water temperatures and longer steeping times generally extract more polyphenols and caffeine. Proper brewing technique helps maximize the catechins and other bioactive compounds present in the leaves, though no research specifically quantifies how brewing variables affect Jin Xuan cultivar composition. Using fresh, filtered water and quality loose leaves rather than tea bags typically yields better extraction of the tea's flavor and theoretical bioactive compounds.

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