Black tea vs green tea: calories compared

The trials pick no health winner. Meta-analyses of 13 black tea and 36 green tea trials in adults put the systolic blood pressure drop at about 1 mmHg for each.

In one trial, four 8 fl oz (240 mL) cups of black tea held 168 mg of caffeine, about 42 mg a cup. US survey data put a cup of hot green tea at about 29 mg. The sources differ, so the gap is rough. Black tea also averages twice the fluoride of green.

With a rice meal, one cup of black tea cut iron absorption by about half and two cups by two thirds. Green tea's EGCG, at 150 to 300 mg, cut it by 14 to 27 percent. Either tea with a folic acid tablet lowered peak blood folate by close to 40 percent. In healthy adults, a 5 fl oz (150 mL) cup of green tea cut blood nadolol, a beta blocker, by about 63 percent, and by 46 percent if drunk an hour earlier. An extract cut lisinopril by two thirds. Black tea has no such tests. Liver harm came from concentrated extracts, not brewed tea.

Pick the tea you enjoy. With low iron, keep tea away from meals. On nadolol or lisinopril, ask your prescriber about green tea. In pregnancy, keep all caffeine under 200 mg a day.

Evidence behind this note

1. Level A By a meta-analysis of 13 RCTs, black tea lowered systolic blood pressure by 1.04 mmHg and diastolic by 0.59 mmHg versus control. Food Funct, 2021
2. Level A Across 36 RCTs in adults, green tea supplementation lowered systolic blood pressure by about 1.1 mmHg and diastolic by about 1.1 mmHg. Blood Press, 2025
3. Level B In an RCT in 21 healthy men, 4 or 6 mugs of black tea a day (168 or 252 mg caffeine) hydrated as well as the same amount of water. Br J Nutr, 2011
4. Level E A cup of hot brewed green tea (240 g) carries about 29 mg caffeine and 2.4 calories in US survey data. USDA FNDDS, Tea, hot, leaf, green, FDC 2710490
5. Level B In a stable-isotope trial in young Indian women, 1 or 2 cups of black tea with a rice meal cut iron absorption by 49% and 66% in iron-replete women and by 59% and 67% in women with anemia. Am J Clin Nutr, 2008
6. Level B In 30 women with low iron stores, 300 mg EGCG a day cut nonheme iron absorption by 27% and 150 mg by 14% versus placebo. Phytomedicine, 2005
7. Level B In a randomized crossover study in healthy volunteers, taking a 0.4 mg folic acid tablet with black tea instead of water cut peak serum folate by 38.6% and total exposure by 17.9%. Biopharm Drug Dispos, 2008
8. Level B One cup of brewed green tea taken with the beta blocker nadolol cut its blood exposure by about 63% in 11 healthy volunteers, and by 46% when drunk an hour before. Br J Clin Pharmacol, 2020
9. Level B A green tea extract drink with about 300 mg EGCG cut blood levels of the blood pressure drug lisinopril by about two thirds in 10 healthy volunteers. Clin Transl Sci, 2021
10. Level C A systematic safety review of 159 human intervention studies found liver harm only with concentrated catechin boluses, not brewed tea, and derived a safe intake of 338 mg EGCG a day as a solid dose. Regul Toxicol Pharmacol, 2018
11. Level C A review of 88 studies found fluoride release rises with brewing time, with black tea bags reaching 6.01 mg/L after 30 minutes and black tea averaging 2.73 mg/L. Crit Rev Food Sci Nutr, 2025
12. Level C The Nordic Nutrition Recommendations 2023 review advises pregnant women not to exceed 200 mg of caffeine a day, the level EFSA set as safe for the fetus. Food Nutr Res, 2024

Written from the studies and agency guidance we hold for both foods, reviewed by the Bioma editorial system. How we verify.

Read more about these foods

• Black tea: a small drop in blood pressure and a large cut in iron absorption
• Green tea: small measured effects and two drug clashes

What the studies say

• Does green tea help with weight loss? About a kilo, and Cochrane found none outside Japan
• Is green tea safe during pregnancy? A few cups, likely yes. Extracts are another matter

Rankings and guides

• Calories: what it does and what the evidence shows
• Which foods give the most protein for the fewest calories?
• Dietary fat: what it does and how much you need
• Green tea: full nutrition facts

More comparisons

• Green tea vs coffee

• Black tea: USDA FoodData Central, Beverages, tea, black, brewed, prepared with tap water, FDC ID 173227 · all forms of black tea
• Green tea: USDA FoodData Central, Beverages, tea, green, brewed, regular, FDC ID 171917 · full profile · all forms of green tea

Each food is one USDA entry, chosen as it is usually eaten. Other cuts, brands and preparations differ; the links show them. % DV uses FDA Daily Values for adults. How we verify.