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Black Tea

Supplement Forms/Alternate Names:

Red tea (due to the color when brewed)


Black tea is a bitter tea made from the leaves of a small shrub. It has been used to help lower cholesterol, blood pressure, and improve alertness. Black tea can also be taken as a pill, powder, or extract.


2 to 3 cups per day

What Research Shows

Likely Effective

  • Cardiovascular disease (CVD) —likely to lower LDL (“bad”) cholesterol and blood pressure B1,B2
  • High blood pressure —likely to lower blood pressure E1-E3
  • High cholesterol — likely to lower LDL (“bad”) cholesterol F1-F3
  • Stroke —likely to help prevent future strokes G1

May Be Effective

  • Diarrhea —may reduce diarrhea in children D1

Unlikely to Be Effective

  • Coronary artery disease —unlikely to protect against the disease C1

Not Enough Data to Assess

  • Attention A1

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Safety Notes

It is likely safe to take black tea in small doses for a short time. Not enough studies have been done to say whether it is safe to take for a long period. Women who are pregnant or breastfeeding should not consume large amounts of black tea.


Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse, such as:

  • People taking blood thinners should talk to their doctor before taking black tea. It may lower how well their medicines work.
  • People with seizures or bipolar disorder should talk to their doctors before taking black tea. It may interact with their medicines.


A. Attention

A1. De Bruin EA, Rowson MJ, et al. Black tea improves attention and self-reported alertness. Appetite. 2011;56(2):235-240.

B. Cardiovascular Disease

B1. Bahorun T, Luximon-Ramma A, et al. The effect of black tea on risk factors of cardiovascular disease in a normal population. Prev Med. 2012 May;54 Suppl:S98-102.

B2. Hartley L, Flowers N, et al. Green and black tea for the primary prevention of cardiovascular disease. Cochrane Database Syst Rev. 2013;18(6):CD009934.

C. Coronary Artery Disease

C1. Wang ZM, Zhou B, et al. Black and green tea consumption and the risk of coronary artery disease: a meta-analysis. Am J Clin Nutr. 2011 Mar;93(3):506-515.

D. Diarrhea

D1. Doustfatemeh S, Imanieh MH, et al. The Effect of Black Tea (Camellia sinensis (L) Kuntze) on Pediatrics With Acute Nonbacterial Diarrhea: A Randomized Controlled Trial. J Evid Based Complementary Altern Med. 2017 Jan;22(1):114-119.

E. High Blood Pressure

E1. Greyling A, Ras RT, et al. The effect of black tea on blood pressure: a systematic review with meta-analysis of randomized controlled trials. PLoS One. 2014;9(7):e103247.

E2. Liu G, Mi XN, et al. Effects of tea intake on blood pressure: a meta-analysis of randomised controlled trials. Br J Nutr. 2014 Oct 14;112(7):1043-1054.

E3. Yarmolinsky J, Gon G, et al. Effect of tea on blood pressure for secondary prevention of cardiovascular disease: a systematic review and meta-analysis of randomized controlled trials. Nutr Rev. 2015 Apr;73(4):236-246.

F. High Cholesterol

F1. Wang D, Chen C, et al. Effect of black tea consumption on blood cholesterol: a meta-analysis of 15 randomized controlled trials. PLoS One. 2014 Sep 19;9(9):e107711.

F2. Zhao Y, Asimi S, et al. Black tea consumption and serum cholesterol concentration: Systematic review and meta-analysis of randomized controlled trials. Clin Nutr. 2015;34(4):612-619.

F3. Troup R, Hayes JH, et al. Effect of black tea intake on blood cholesterol concentrations in individuals with mild hypercholesterolemia: a diet-controlled randomized trial. J Acad Nutr Diet. 2015 Feb;115(2):264-71.e2.

G. Stroke

G1. Arab L, Liu W, et al. Green and black tea consumption and risk of stroke: a meta-analysis. Stroke. 2009;40(5):1786-1792.

Last reviewed July 2019 by EBSCO CAM Review Board  Last Updated: 2/7/20