Green tea benefits and risks: what matters in your cup

The everyday benefits are straightforward

Green tea earns a place in the kitchen when you enjoy drinking it. A plain cup offers a savoury, grassy or lightly toasted flavour without needing syrup. If it replaces a sweetened drink, that swap can reduce added sugar; simply adding tea to an unchanged diet does not make the rest of the diet healthier.

Tea also counts towards fluid intake, according to NHS hydration guidance. You do not need to drink it at a particular hour, on an empty stomach or in a special sequence with meals to make it worthwhile. If you are choosing between tea and a more substantial drink, the healthy drinks guide compares their different roles.

What green tea research can and cannot show

NCCIH's green tea overview reports small cholesterol reductions in trials, most of which tested extracts. Cancer findings are inconsistent; reported weight effects are modest and variable. None of those findings establishes a home-brewed cup as treatment.

Study design matters. People who choose tea may differ in other habits, so an association alone cannot show that tea caused an outcome. A capsule study also cannot tell you how many mugs to brew: the preparation, concentration and exposure are different.

The useful question is whether a drink fits your day. For a broader look at ingredient claims, our drinks and inflammation guide separates food choices from treatment claims and explains why unexplained swelling needs its own assessment.

Caffeine: use the whole day as your reference

The FDA's caffeine guide lists 37 mg as a typical amount in 12 fluid ounces, about 355 ml, of green tea. Individual products vary. That number is an illustration, not a measurement of your mug.

For most adults, the FDA cites 400 mg per day as an amount not generally associated with negative effects. It is not a target or a guarantee for everyone. Count coffee, tea, energy drinks and other sources together; poor sleep, jitters or palpitations are reasons to reassess intake.

During pregnancy, the NHS advises no more than 200 mg daily from all sources. Decaffeinated tea still contains some caffeine. If you prefer a drink made without tea leaves, our fresh ginger tea recipe offers a different flavour.

Brew one measured cup

For one approximately 250 ml serving, use 2 g loose green tea, 250 ml water and an infuser or fine sieve. Allow about five minutes overall. Leaf shapes make teaspoon measures unreliable, so weigh once if you can; otherwise follow the packet's serving guidance.

Heat the water to 80°C, or follow a lower temperature specified on the tea packet. Pour it over the leaves and start a timer. Taste after two minutes, then strain completely; give it up to one extra minute if you prefer more strength. Let the tea reach a comfortable drinking temperature.

Without a thermometer, use the packet's method and allow freshly boiled water to cool before brewing. Cooling time changes with the kettle, vessel and room, so a fixed wait cannot guarantee 80°C. Start with a short steep and adjust the next cup.

If it tastes harsh, try cooler water or a shorter infusion before adding sweetener. If it is thin, increase the leaves slightly next time while keeping the water and timing consistent. Change one variable at a time so you can repeat the version you enjoy.

Risks deserve context, especially with extracts

NCCIH reports uncommon liver injury mainly with concentrated green tea extracts in tablets or capsules. That concern should not be transferred uncritically to ordinary tea, but it is a reason to avoid treating extracts as a stronger version of a beverage.

Medication interactions also matter: NCCIH identifies interactions involving nadolol, atorvastatin and raloxifene, with differences between products. If you take regular medication and plan substantial changes in tea intake, ask a pharmacist about your particular medicine. Do not stop prescribed treatment.

If tea repeatedly makes you feel unwell, stop drinking it and consider another beverage. Our peppermint tea guide explains an alternative and its reflux caveat. For a different green tea preparation, try the measured Kashmir-inspired kahwa recipe.