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Black tea

Camellia sinensis

Also known as black tea, red tea, English breakfast, Assam, Darjeeling

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Leaves of the same plant as green tea, allowed to oxidise fully before drying, which converts most catechins into larger theaflavin and thearubigin polyphenols. The USDA entry is for the brewed drink rather than the dry leaf.

Energy & MetabolismHeart Health

Potential health benefits

Best supported: Moderate

Ordered by how well the human research supports them — strongest first. A rating describes the state of the evidence, not how impressive the food is. How we rate evidence.

Alertness and energy

Energy & Metabolism
Moderate evidence

Black tea supplies caffeine, and caffeine has well-replicated short-term effects on alertness and reaction time. Doses per cup are lower and more variable than coffee, and much of the benefit in habitual drinkers is the wearing off of overnight withdrawal rather than a gain above baseline.

Moderate evidence. Several human studies point the same way, with real caveats.

2 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Cardiovascular risk markers

Heart Health
Limited evidence

Observational data links regular tea drinking with modestly lower cardiovascular risk in several large cohorts. Tea drinking travels with a lot of other habits, and no trial has tested hard outcomes, so this stays a correlation.

Limited evidence. Early human work, or mostly lab and animal research.

1 source

Deep research mode adds each paper’s own conclusion and stated limitations.

Healthy blood pressure

Heart Health
Limited evidence

Meta-analyses of black tea trials report small reductions in systolic and diastolic blood pressure. The changes are modest, the trials heterogeneous, and acute caffeine can push blood pressure the other way in people who rarely drink it.

Limited evidence. Early human work, or mostly lab and animal research.

3 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Ask about Black tea

Ask about Black tea

Answers are written only from the entries on this page — the same nutrients, compounds, claims and citations you can read above. Nothing is added from outside the database, and every answer lists what it was built from.

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Key nutrients

Nutrient content per 100 grams
NutrientAmount% DV
Macronutrients
Calories1 kcal0%
Protein0 g0%
Total fat0 g0%
Carbohydrate0.3 g0%
Fibre0 g0%
Total sugars0 g—
Water99.7 g—
Fats
Saturated fat0.0020 g0%
Monounsaturated fat0.0010 g—
Polyunsaturated fat0.0040 g—
Cholesterol0 mg0%
EPA (omega-3)0 g—
DHA (omega-3)0 g—
DPA (omega-3)0 g—
Linoleic acid (omega-6)0.0010 g—
Vitamins
Vitamin A0 µg0%
Vitamin C0 mg0%
Vitamin D0 µg0%
Vitamin E0 mg0%
Vitamin K0 µg0%
Thiamin (B1)0 mg0%
Riboflavin (B2)0.014 mg1%
Niacin (B3)0 mg0%
Pantothenic acid (B5)0.011 mg0%
Vitamin B60 mg0%
Folate5 µg1%
Vitamin B120 µg0%
Choline0.4 mg0%
Minerals
Calcium0 mg0%
Iron0.02 mg0%
Magnesium3 mg1%
Phosphorus1 mg0%
Potassium37 mg1%
Sodium3 mg0%
Zinc0.02 mg0%
Copper0.01 mg1%
Manganese0.219 mg10%
Selenium0 µg0%
Other measured compounds
Beta-carotene0 µg—
Alpha-carotene0 µg—
Lycopene0 µg—
Lutein + zeaxanthin0 µg—
Caffeine20 mg—
Ash0.04 g—

Nutrient values are per 100 g of the USDA reference entry named on this page and vary with variety, growing conditions, storage and preparation.

Source record: Beverages, tea, black, brewed, prepared with tap water (USDA FoodData Central, FDC ID 173227).

% DV uses the FDA Daily Values for adults and children aged 4 and over. A dash means no Daily Value has been established for that nutrient.

Bioactive compounds

Compounds present in meaningful amounts. Presence is banded rather than quantified, because whole-food levels vary enormously with variety, growing conditions, storage and preparation.

How preparation changes things

Only effects with real support are listed. If a preparation method is missing, it is because nothing dependable is documented — not because it makes no difference.

  • brewedIncreases polyphenol and caffeine extraction

    Longer steeping and hotter water extract more caffeine and more tannin, producing a stronger and more astringent cup. Most of the caffeine comes out within the first couple of minutes.

  • with foodReduces non-heme iron absorption

    Tea taken with a meal binds non-heme iron; adding milk does not remove the effect, though vitamin C in the meal partly offsets it.

Things to know

Allergies, interactions and intake concerns. Every food gets this section — a reference where everything is uniformly good is not a reference.

  • Interaction

    Strongly reduces non-heme iron absorption

    Black tea is high in tannins and reduces absorption of non-heme iron from a meal more than green tea does. This matters for people who are iron-deficient, menstruating heavily, pregnant, or eating mainly plant sources of iron; drinking it between meals largely avoids the problem.

  • Too much

    Caffeine effects on sleep, anxiety and pregnancy limits

    A cup of black tea supplies roughly a third to half the caffeine of a cup of brewed coffee, varying widely with strength and steeping. Sensitive people experience disturbed sleep, palpitations and worsened anxiety, and pregnancy guidance caps total caffeine at around 200 mg a day.

  • Worth knowing

    Very hot drinks and the oesophagus

    Drinking beverages above about 65 °C has been classified as probably carcinogenic to the oesophagus, based on evidence from populations that drink tea and maté very hot. Letting the cup cool for a few minutes is the entire mitigation.