Antioxidants in Green Tea: Benefits & Brewing Guide

Green tea’s health benefits are driven by plant antioxidants called catechins. The most studied is EGCG, which has been linked with cardiometabolic support and recovery from everyday oxidative stress. Brewing technique—and any add‑ins—can change the bioavailability of those antioxidants.

Quick answer (what most people want to know): The main antioxidants in green tea are catechins—especially EGCG. To get more in your cup, brew at 175–185°F (80–85°C) for 2–3 minutes, add lemon or a pinch of vitamin C, and skip the milk if antioxidants are your goal. Brewed tea is generally safe; avoid high‑dose green tea extracts unless supervised (EFSA Panel, 2018).

Key takeaways

• Catechins are the primary antioxidants. They neutralize free radicals and support your body’s own defense systems (Forester & Lambert, 2013).
• Proper brewing is key. Around 175–185°F (80–85°C) for 2–3 minutes maximized EGCG in one lab study while keeping flavor pleasant; hotter/longer steeps can degrade EGCG via epimerization (Özdemir et al., 2015).
• Add citrus or vitamin C. Lemon or ascorbic acid can stabilize catechins during digestion and boost their recovery several‑fold in digestion models (Ferruzzi et al., 2007).
• Milk may blunt the effect. Some models show milk proteins bind catechins and can reduce bioaccessibility; findings are mixed, but for maximum antioxidants, go plain or add citrus (Zhao et al., 2021).
• Safety first. Regular tea is a safe daily habit for most adults. High‑dose supplements (≥800 mg EGCG/day for months) have been linked to elevated liver enzymes in some users (EFSA Panel, 2018).

What are the antioxidants in green tea?

Green tea comes from Camellia sinensis leaves quickly heated to stop oxidation. That preserves catechins—chiefly EGCG, plus EGC, ECG, and EC. These polyphenols can (Forester & Lambert, 2013):

• Disarm reactive oxygen species (ROS) and bind metals that drive oxidation
• Activate the body’s antioxidant defenses via cell‑signaling pathways like Nrf2
• In certain laboratory studies, behave as pro‑oxidants that stress cancer cells—this is a proposed mechanism in cells, not a proven effect in humans

Green tea also naturally contains caffeine and L‑theanine. A typical cup provides roughly 30–40 mg caffeine—a gentle lift for most people (Jówko, 2015).

Health benefits linked to green tea antioxidants

Human evidence is strongest for heart and metabolic support, with additional exercise‑related effects:

• Cardiovascular: Randomized trials and meta‑analyses report modest reductions in LDL and total cholesterol with green tea beverages or extracts (Zheng et al., 2011; Maki et al., 2020).
• Metabolic: A recent meta‑analysis found improvements in fasting glucose and HbA1c alongside lipid changes, with modest effects on diastolic blood pressure (Gholami et al., 2023).
• Exercise & recovery: Catechins can increase fat oxidation and raise plasma antioxidant capacity; performance effects in trained athletes are mixed (Jówko, 2015).

Bottom line: Green tea can be a helpful piece of a healthy routine—just don’t expect it to be a standalone solution.

How much antioxidant is in a cup?

It varies a lot by leaf, grade, and preparation.

• In one experiment, brewing at 85°C for 3 minutes produced about 50.7 mg EGCG per 100 mL—roughly 125 mg per 8‑oz cup—while hotter/longer steeps decreased EGCG via epimerization (Özdemir et al., 2015).
• Regulatory reviews note a wide range of EGCG in brewed tea, reflecting product and preparation differences (EFSA Panel, 2018).
• Matcha, a powdered green tea you drink whole, often delivers higher catechins and caffeine per serving versus a typical infusion (Kochman et al., 2020).

How to brew for maximum antioxidants (and great taste)

• Heat fresh water to 175–185°F (80–85°C) and steep 2–3 minutes. This hits a sweet spot for catechin yield and flavor (Özdemir et al., 2015).
• Add citrus or a pinch of vitamin C. Ascorbic acid stabilizes catechins through digestion, boosting their recovery several‑fold in model systems (Ferruzzi et al., 2007).
• Limit milk if antioxidants are the goal. Protein–catechin binding can reduce bioaccessibility and measured antioxidant activity in several models; human data are mixed, but plain or citrus‑enhanced tea is the most conservative approach (Zhao et al., 2021).
• Avoid boiling‑hot, prolonged steeps. Excess heat/time can convert EGCG into less active forms (epimerization) and increase bitterness (Wang et al., 2001).

If you prefer a stronger cup, use a bit more leaf rather than much longer steep times.

Green vs. black tea: which has more antioxidants?

All true teas deliver meaningful polyphenols—but the profiles differ. Green tea is richer in catechins (like EGCG), while black tea—oxidized during processing—converts many catechins into theaflavins. In a lab model of LDL oxidation, theaflavins demonstrated antioxidant potency comparable to catechins (Ishimoto et al., 2001). While this is a laboratory model, observational and clinical studies suggest both tea types can support cardiometabolic health; choosing the style you enjoy helps you stay consistent.

Green tea bioavailability: why additives and timing matter

Catechins are relatively unstable in the gut. In digestion models, <20% of total catechins remained from plain green tea, but adding vitamin C or citrus juices raised recovery (e.g., EGC 81–98%, EGCG 56–76%) (Ferruzzi et al., 2007).

Other practical factors:

• Food vs. fasting: Drinking brewed tea on an empty stomach can raise blood levels of free EGCG compared with drinking with food (Chow et al., 2005; Yang et al., 2011). Do not apply this to high‑dose extracts—taking concentrated catechins on an empty stomach may increase liver stress (EFSA Panel, 2018).
• pH and temperature: Lower pH improves catechin stability, and high heat can drive epimerization (EGCG → GCG) (Wang et al., 2001). This supports strategies like adding lemon and avoiding boiling‑hot, prolonged steeps.

Safety and sensible intake

• Traditional infusions: Long histories of use and clinical data support safety for daily drinkers; most adults can enjoy multiple cups per day (EFSA Panel, 2018).
• Extracts/supplements: Doses ≥800 mg EGCG/day for months have increased liver enzymes in a minority of users; rare liver injury has been reported. Avoid high‑dose extracts unless supervised (EFSA Panel, 2018).
• Very hot beverages: Regularly drinking liquids above 55–60°C (131–140°F) is linked with higher esophageal cancer risk; let tea cool a bit before sipping (Harvard T.H. Chan, 2020).

Be extra cautious if you are:

• Pregnant or breastfeeding
• Managing liver disease
• Taking medications that may interact with green tea or caffeine
• Using high‑dose green tea extracts

Check with a clinician if any of the above apply.

Quick FAQ

• Does lemon really boost antioxidant availability? Yes—acidifying your brew with citrus or vitamin C helps catechins stay intact through digestion (Ferruzzi et al., 2007).
• Is milk a problem for green tea’s antioxidants? It can be. Milk proteins may bind catechins and lower their measured activity, though results vary (Zhao et al., 2021).
• How many cups are safe? Multiple cups per day appear safe for most adults when consumed as brewed tea; avoid high‑dose extracts unless supervised (EFSA Panel, 2018).
• Green or black tea for antioxidants? They provide different compounds with similar potential benefits; choose the one you’ll drink consistently.

Track what matters with BodySpec

Green tea’s catechins are linked with better lipid profiles and increased fat oxidation in some studies. If you’re using tea alongside training and nutrition changes, track the corresponding changes in your body composition. A BodySpec DEXA scan quantifies body composition and visceral fat with medical‑grade precision—so you can see whether habits are improving fat mass, lean mass, and health risk markers. When you’re ready to quantify progress, book a BodySpec scan in minutes.