Tea: types, benefits and caffeine content

What types of tea are there, and how do they differ?

Tea comes from Camellia sinensis. The way its leaves are processed distinguishes green, white, oolong, black and pu-erh tea [1]. Matcha is powdered green tea. Rooibos and infusions made from other plants use different ingredients, so they are not tea [1].

Green tea is heated soon after harvesting to stop the leaves from oxidising. White tea is minimally processed. Oolong is partially oxidised, while black tea is more extensively oxidised. Pu-erh also undergoes microbial fermentation. These differences create distinct flavours and alter some compounds; the composition of commercial teas overlaps [1]. See “Coffee, tea and caffeine while breastfeeding”.

Choose the flavour you enjoy first. If a strong cup tastes bitter, try using fewer leaves or steeping it for less time. A lighter colour does not guarantee less caffeine [2].

How much caffeine is in a cup of tea?

As a reference, a 220 ml cup of black tea contains about 50 mg of caffeine [2]. This is an estimate. The amount varies with the leaves, how much you use, cup size and preparation. There is no single universal figure for each tea colour.

According to EFSA, single doses of up to 200 mg of caffeine do not raise safety concerns for healthy, non-pregnant adults [2]. Regular consumption of up to 400 mg per day also does not raise safety concerns in this group, counting all sources [2]. These are safety thresholds, not targets to reach. A 100 mg dose close to bedtime may affect some people’s sleep [2].

During pregnancy, EFSA considers total caffeine intake of up to 200 mg per day not to raise safety concerns for the foetus [2]. During breastfeeding, we follow a cautious limit of up to 200 mg of caffeine per day [2]. For children and adolescents, EFSA proposes 3 mg per kilogram of body weight per day as a safe level, not a consumption target [2]. Ask your healthcare professional for individual advice. You can read EFSA’s caffeine summary.

If you want to compare tea with other breakfast drinks, see what to drink in the morning.

What do we know about catechins and the benefits of tea?

Catechins are compounds found mainly in green tea. A substance acting as an antioxidant in a laboratory does not prove that a cup of tea prevents disease in people [3]. Nor does it make tea a weight-loss plan.

EFSA did not establish a causal relationship between consuming tea or its catechins and maintaining a normal weight, reducing body fat or controlling blood glucose [3]. For this reason, no variety is presented as a treatment for obesity or diabetes. If you drink unsweetened tea because you enjoy it, it can be part of your usual drinks; that is different from claiming it has a therapeutic effect.

General claims about polyphenols belong in another guide. Here, the practical question is about tea. If you are monitoring your blood pressure, our hypertension guide explains the overall eating pattern.

Does green tea have any special benefits?

Green tea retains a catechin profile that differs from black tea because of how it is processed [1]. This describes its composition; it does not guarantee a clinical advantage. In consultations, we hear the expectation that a cup will “make up for” other habits. Neither the amount of catechins nor the colour replaces an individual plan when there is a health concern.

If you prefer its flavour, drink it as a beverage. You can make it milder and leave out added sugar. If you are looking to relieve a health condition, talk to your healthcare team before changing what you do.

What changes with matcha?

Matcha is powdered green tea leaf; when you prepare it, you drink the powder rather than removing the leaves. Analysed samples show differences in composition depending on the harvest and preparation temperature [4]. These laboratory analyses do not prove that matcha improves health more than other teas.

There is no fixed caffeine amount per glass either. It depends on how much powder you use and how much you add to the drink. If you order it prepared, ask how much it contains. If you are sensitive to caffeine, start with a small amount. Adding milk or a plant-based drink changes the flavour and texture; it does not turn the drink into a treatment.

Why should you be careful with concentrated extracts?

Green tea infusion and a concentrated extract do not have the same safety profile. EFSA considers customary infusions generally safe, but warns that catechin supplements may cause liver damage [5]. It could not establish a risk-free dose of extract [5]. Do not use these products to seek a clinical effect. Only your doctor or dietitian-nutritionist should recommend a supplement.

That is why we do not recommend increasing exposure through concentrated products for weight loss. If you already take one and have questions, review its ingredients with your doctor or pharmacist. For general questions about plant products and the liver, see the medicinal plants guide. See “Foods containing tryptophan”.

How can you prepare tea and enjoy it?

Use hot water and tea leaves, and adjust the steeping time until you get the flavour you want. Steeping time changes the flavour; the final caffeine content remains variable [2]. If it tastes bitter, start with fewer leaves. You do not need to force yourself to drink it or aim for an exact temperature for health reasons.

To prepare matcha, mix a small amount of powder with water and whisk until dispersed. You can then add the drink of your choice. If you buy bottled tea, check the sugars on the label before comparing it with a plain infusion.

In a small trial in women without anaemia, drinking tea one hour after a meal containing non-haem iron reduced the observed interference with its absorption [6]. If you are concerned about iron, read our guide to iron-deficiency anaemia and nutrition.

What questions come up in consultations?

“White tea has less caffeine.” Colour alone is not enough to predict it. The actual amount depends on the prepared drink [2]. If you need to reduce your intake, start with the size and timing of your cups.

“Red tea helps you lose weight.” There is no clinical evidence to justify drinking pu-erh for weight loss. The European assessment also did not support weight-control claims for tea and its catechins [3].

“The more matcha, the better.” When you drink matcha, you consume ground tea leaf. Let the flavour and your tolerance guide you, without turning a drink into a test of how much caffeine you can handle.