Green Tea: Benefits, How to Prepare It Properly and Side Effects

IMPORTANT: Green tea contains caffeine and tannins, so it should be enjoyed in moderation. People with iron-deficiency anemia, palpitations, anxiety or insomnia, as well as pregnant and breastfeeding women, should limit their intake and talk to a doctor. Green tea may interact with certain medications — especially blood thinners (warfarin), heart medications, stimulants and some blood-pressure treatments. Concentrated green tea extracts (supplements) have, in rare cases, been linked to liver problems; do not confuse a cup of tea with a high-dose supplement. This article is for informational purposes and does not replace medical advice.

Aunt Veronica, a slight, wiry woman from the mountains, had a habit that no one in the family could ever talk her out of: every afternoon, around four o’clock, she would put the kettle on, let the water “rest” for a minute after it came to a boil, and then pour it over the thin green leaves she kept in a tin box, sheltered from the light. “Don’t scald the leaf, dear,” she would tell me, “because if you scald it, the tea turns out as bitter as gall and puckers your mouth.” She would wait exactly as long as it took her to count slowly to sixty, strain it, and sip slowly, her gaze drifting toward the hills. She said that ever since she had switched from coffee to green tea, those irregular heartbeats from her youth had faded, and she no longer felt that heaviness in her legs in the evening.

Later I learned this was not just an old wives’ tale. Green tea is today one of the most studied beverages in the world, and the thousands-of-years-old folk tradition of Asia often meets what modern studies suggest about it. In this article I will tell you, at a leisurely pace, what green tea is, why it is so prized, how to brew it properly so you spoil neither its taste nor its properties, and what to watch out for.

Green tea comes from the leaves of the very same plant that gives us black and oolong tea — Camellia sinensis, a shrub native to Southeast Asia. The crucial difference lies in the processing: for green tea, the freshly picked leaves are heated quickly (by steaming, as in Japan, or by pan-firing, as in China) right after harvest. This step stops oxidation — the leaf’s “rusting” — and preserves the green color and most of the active compounds. That is precisely why green tea is considered the “rawest” of true teas and the richest in antioxidants.

Table of Contents

• What green tea is and where it comes from
• Composition and active principles
• Health benefits
• How to brew green tea properly (step-by-step)
• When and how much to drink
• Combinations with other herbs and flavors
• Types of green tea
• Lifestyle and practical tips
• Practical Tips and Common Mistakes
• Precautions and side effects
• Conclusion
• Frequently Asked Questions

What green tea is and where it comes from

Green tea has its roots in ancient China, where legend holds it was discovered thousands of years ago when a few leaves of Camellia sinensis fell by chance into an emperor’s boiling water. From there it spread to Japan, Korea and the rest of Asia, becoming not merely a drink but a genuine art — think of the Japanese tea ceremony, in which every gesture carries meaning.

Unlike black tea, which is fully oxidized, or oolong, which is partly oxidized, green tea is unoxidized or only very lightly oxidized. The leaves stay green, and the brew takes on a color ranging from pale yellow to golden-green, with a fresh, lightly vegetal taste, sometimes with notes of grass, seaweed, nuts or flowers, depending on the variety and the region it comes from.

Today the main producing countries are China and Japan, but quality green tea can be found in other regions too. In recent decades it has grown steadily more popular here as well, both as an everyday drink and as part of a more health-conscious lifestyle.

Composition and active principles

What makes green tea special is the rare combination of compounds it contains. Here are the most important ones:

• Catechins — a category of polyphenols with powerful antioxidant action. The best known is EGCG (epigallocatechin gallate), considered the “star” of green tea and responsible for much of its studied effects.
• Caffeine — present in smaller amounts than in coffee, it offers a gentle stimulation without coffee’s “jolt.”
• L-theanine — an amino acid almost unique to tea, which promotes a state of alert calm. The combination of caffeine and L-theanine is often described as producing “calm energy,” focus without jitters.
• Tannins — they give the astringency and slightly bitter taste; they also affect iron absorption.
• Vitamins and minerals — small amounts of vitamin C, B-group vitamins, manganese and potassium.
• Chlorophyll and other plant compounds that contribute to the color and the antioxidant profile.

Both folk tradition and modern studies suggest that it is precisely this wealth of catechins, especially EGCG, that underlies most of the beneficial effects attributed to green tea.

Health benefits

A rich source of antioxidants

Antioxidants are molecules that help the body cope with oxidative stress — that cellular “rusting” caused by free radicals. Green tea is one of the most accessible sources of polyphenols in the everyday diet. Studies suggest that regular, moderate consumption can support the body’s natural defense mechanisms against oxidative stress, contributing to a general sense of well-being.

Support for heart health

Asian tradition has long linked green tea to a healthy heart. Modern research suggests that, within the context of a balanced lifestyle, regular green tea consumption may support cardiovascular health through a positive influence on the lipid profile and the blood vessels. It is not a “heart medicine,” but it can be a useful piece in a mosaic of healthy habits.

Support for metabolism and weight management

Green tea is probably best known as a “weight-loss ally.” The combination of caffeine and catechins is studied for its ability to support an active metabolism. Be careful, though: green tea does not melt away the pounds on its own. It can be a modest aid, useful only alongside a balanced diet and physical activity. Replacing sugary drinks and sodas with a cup of unsweetened green tea is, in itself, a win.

Mental clarity and focus

This is where the magic of L-theanine comes in. While caffeine provides energy, L-theanine tempers nervousness and brings about a state of calm focus. Many people prefer green tea precisely because it gives them alertness without the shakes, without palpitations, without that sudden energy crash that follows coffee. The tradition of Buddhist monks, who drink green tea to stay awake and attentive during long meditation, lends support to this observation.

Support for immunity and oral health

The polyphenols in green tea have been studied for their properties in supporting natural defenses. In folk medicine, gargling with cold green tea was used for a sore throat, while the natural fluoride and catechins may contribute to better oral hygiene, helping to combat bad breath.

Hydration and a healthier alternative

Although it contains caffeine, green tea drunk in moderation contributes to your daily fluid intake. For someone used to fizzy drinks or many strong coffees, switching to green tea is a gentle and beneficial change.

How to brew green tea properly (step-by-step)

This is where the real difference is made. Green tea is delicate — scalded with water that is too hot, or left to steep too long, it turns bitter and astringent. Here is the correct method:

1. Choose the right water. Use fresh water, preferably filtered, not water that has been reheated several times.
2. Do not use boiling water. This is mistake number one. The ideal temperature for most green teas is around 70–80°C (160–175°F). If you don’t have a thermometer, let the boiled water “rest” uncovered for 1–2 minutes after it has come to a boil.
3. Measure the leaves. One teaspoon of green tea (about 2–3 g) per 200–250 ml cup is a good starting amount.
4. Pour the water over the leaves, not the other way around, and start the timer.
5. Steep briefly. For green tea, 1–3 minutes is enough. The longer you steep, the more tannins you extract and the more bitter the taste becomes.
6. Strain immediately. Do not leave the leaves in the water once the time is up.
7. Re-steep. Quality leaves can be infused 2–3 times; the second infusion is often the most aromatic.

Tip: don’t sweeten automatically. Good green tea has a delicate taste worth savoring as it is. If you do want something sweet, a teaspoon of honey added to slightly cooled tea is gentler than sugar.

When and how much to drink

For most healthy adults, 2–3 cups a day is a reasonable and pleasant amount. The ideal moments are in the morning, as a gentler alternative to coffee, and in the early afternoon, for a focus boost. Avoid green tea late in the evening, because of the caffeine that can disturb sleep.

One important detail: green tea is best drunk between meals, not during them, especially if you eat foods rich in plant-based iron, since the tannins can reduce iron absorption.

Combinations with other herbs and flavors

Green tea pairs beautifully with many flavors:

• With mint — a classic combination, refreshing and digestion-friendly (think Moroccan tea).
• With lemon — a squeeze of lemon juice not only improves the taste but may help with the stability of the catechins.
• With ginger — for a warm, spicy note, lovely in winter.
• With jasmine — jasmine flowers give the tea a delicate, floral fragrance (classic jasmine tea).
• With citrus and elderflower — for a summer version, served cold.

Types of green tea

The world of green tea is surprisingly varied:

• Sencha — the most common Japanese green tea, fresh and balanced.
• Matcha — finely ground leaves whisked into powder; very concentrated.
• Gyokuro — a luxury shade-grown Japanese tea, sweet and velvety.
• Gunpowder — Chinese tea rolled into small pellets, robust.
• Longjing (Dragon Well) — pan-fired Chinese tea with nutty notes.
• Genmaicha — green tea blended with roasted rice, with a nutty, bready taste.

Lifestyle and practical tips

Green tea is not a magic solution but one stone in a larger mosaic. What matters most is that your daily routine is balanced: enough sleep, regular movement, meals with vegetables, fruit, whole grains and healthy fats, good hydration and stress management. Within this context, the calm ritual of brewing a cup of green tea can itself be a beneficial pause, a moment of respite in which you slow your pace.

Store green tea properly: in an airtight container, away from light, heat, moisture and strong smells. Tea leaves easily absorb surrounding odors, so don’t keep them next to spices or coffee. Green tea “ages” faster than black tea, so buy quantities you will use up within a few months.

Practical Tips and Common Mistakes

Mistake no. 1: Scalding with boiling water. This is the most frequent mistake. Water at 100°C “burns” the leaves and extracts too many tannins, resulting in a bitter tea. Let the water cool a little.

Mistake no. 2: Steeping too long. Many believe that “more time = stronger and healthier.” In reality, after 3 minutes you mostly extract bitterness. Stick to 1–3 minutes.

Mistake no. 3: Drinking it on a very sensitive empty stomach. In some people, concentrated green tea drunk on an empty stomach can cause stomach discomfort. If you are sensitive, drink it after a light snack.

Mistake no. 4: Overconsumption. “If it’s good, I’ll drink ten cups.” Excess caffeine and tannins can cause palpitations, nervousness, insomnia and can interfere with iron absorption. Moderation is key.

Mistake no. 5: Confusing tea with concentrated supplements. A cup of tea is something entirely different from a high-dose green tea extract in capsules. Concentrated supplements should only be taken with caution and, ideally, with a doctor’s approval.

Mistake no. 6: Improper storage. Tea left in the light, in open bags or near strong smells quickly loses its aroma and freshness.

Precautions and side effects

Although it is a gentle beverage, green tea is not for everyone in any quantity:

• Iron-deficiency anemia — tannins reduce iron absorption; drink the tea between meals, not during them.
• Pregnancy and breastfeeding — limit caffeine; discuss the appropriate amount with your doctor.
• Anxiety, palpitations, insomnia — caffeine can worsen these conditions.
• Stomach problems — in some people, concentrated tea on an empty stomach irritates the lining.
• Drug interactions — especially blood thinners, stimulants, and some heart and blood-pressure medications.
• Children — because of the caffeine, it is not recommended as a regular drink for little ones.

If you are on medication or have a chronic condition, ask your doctor before making green tea a daily habit.

Conclusion

Green tea is a beverage thousands of years old, prized alike by Asian tradition and modern research for its wealth of antioxidants, for the “calm energy” effect produced by the caffeine–L-theanine combination, and for its role as a gentle ally within a balanced lifestyle. The secret lies in the details: water that is not too hot, brief steeping, quality leaves, proper storage, and above all moderation. Drink it with pleasure, as a soothing ritual, and let it be what it truly is — a simple, healthy joy, not a cure-all. As Aunt Veronica used to say: “Don’t scald the leaf, and don’t rush, dear.”

Frequently Asked Questions

How many cups of green tea can I drink per day? For most healthy adults, 2–3 cups a day is a reasonable amount. People sensitive to caffeine should drink less and avoid tea in the evening.

Does green tea really help with weight loss? It can be a modest support for metabolism, but it does not melt away the pounds on its own. It works only alongside a balanced diet and regular exercise.

At what temperature should green tea be brewed? Ideally around 70–80°C (160–175°F), not with boiling water. Let the boiled water rest for 1–2 minutes before pouring it over the leaves.

How long should it steep? Between 1 and 3 minutes. Longer steeping extracts tannins and makes the tea bitter.

Can I drink green tea while pregnant? Caffeine should be limited during pregnancy. Discuss the appropriate amount with your doctor; in general, moderation is recommended.

Does green tea contain caffeine? Yes, but less than coffee. Thanks to L-theanine, the stimulating effect is gentler and more balanced.

Can green tea be drunk on an empty stomach? Some people tolerate it well, others feel stomach discomfort. If you are sensitive, drink it after a light snack.

Can I re-steep the same leaves? Yes, quality leaves can be infused 2–3 times. The second infusion is often the most aromatic and pleasant.