Hibiscus Tea (Karkadeh / Bissap)

Egyptian (karkadeh, served hot or cold) and West African (bissap) — drunk to "cool the blood"

Evidence: Moderate — meta-analyses of RCTs; one trial found it comparable to captopril

Illustration: Dried hibiscus calyces / karkadeh (Hibiscus sabdariffa)

Illustration: Roselle flowers

What it is and what it is used for

A deep-red tea brewed from the dried calyces of Hibiscus sabdariffa, used traditionally for high blood pressure. Meta-analyses found systolic pressure fell by about 7.6 mmHg and diastolic by about 3.5 mmHg versus control; a Senegalese trial found bissap roughly comparable to the drug captopril for mild-to-moderate hypertension.

Safety and disclaimers

Recipe

Ingredients:

Preparation:

  1. Bring the water to a boil, add the calyces, and steep 10–15 minutes (or cold-brew overnight for bissap).
  2. Strain and sweeten to taste. Serve hot or over ice.

Dosage / directions: Trials used the equivalent of 2–3 cups daily or a standardized extract.

Folk history

In Egypt, karkadeh is the drink of hospitality and of summer — sold by street vendors from great glass jars, ruby-red over ice. West Africans call it bissap and drink it at celebrations. The folk idea was always the same: it 'cools the blood.' In Senegal, researchers put that idea to the test against captopril, and the flower held its own.

Scientific references