Karkadé (hibiscus)

Introduction

Karkadé is made from the calyces of roselle (Hibiscus sabdariffa), a bushy annual plant that can reach 2.4 metres. After flowering, the calyx, the part around the flower, becomes thick, fleshy and bright red, with a tart taste close to cranberry. The plant is grown in tropical and subtropical regions: Sudan, Egypt, Nigeria, India, China, Southeast Asia and Mexico. Its colour comes from anthocyanins; it also contains organic acids, including hibiscus acid, vitamin C and pectin (Da-Costa-Rocha et al., 2014).

History

Its exact origin is still debated. According to a 2014 scientific review, work cited by the authors places its domestication in western Sudan more than 6,000 years ago; other sources point to India.

Traditional uses

In Egypt the calyces are made into an infusion or fermented drinks; in Sudan and Nigeria they are boiled with sugar to make karkadé or zoborodo. In Mexico the same drink is called agua de Jamaica. Karkadé is drunk hot or iced. The Egyptian monograph describes an infusion of 1.25 to 1.5 g of calyces in 240 ml of boiling water for 5 to 10 minutes.

Scientific studies

In 8 healthy volunteers, a drink made with an aqueous karkadé extract raised plasma antioxidant capacity (FRAP) and lowered urinary malondialdehyde, a marker of oxidative stress. In 30 healthy adults, 400 ml a day of a sweetened karkadé drink for 30 days was followed by an average blood pressure falling from 113/77 to 108/73 mmHg and HDL rising from 47.0 to 49.5 mg/dl; LDL and triglycerides did not change. That study had no control group and the participants also exercised, so its results are preliminary. Karkadé is a drink, not a medicine.

Precautions

• It may lower blood pressure: if you take blood-pressure medicine, monitor it and talk to your doctor.
• It may change blood sugar and the effect of some medicines, including those that lower blood sugar, chloroquine and simvastatin.
• Stop it at least 2 weeks before planned surgery.
• Not recommended during pregnancy and breastfeeding, as safety data are lacking.
• Avoid it if you are allergic to plants of the mallow family (Malvaceae).

Further reading: Egyptian Drug Authority