Rooibos
Also Known As: Rooibos , Bush tea, Redbush tea, South African red tea, Red tea
Rooibos is a broom-like member of the legume family of plants growing in South Africa's fynbos.
The generic name comes from the plant Calicotome villosa, aspalathos in Greek. This plant has very similar growth and flowers to the redbush. The specific name linearis comes from the plant's linear growing structure and needle-like leaves.
The plant is used to make an herbal tea called rooibos tea, bush tea (esp. Southern Africa), redbush tea (esp. UK), South African red tea, or red tea. The product has been popular in Southern Africa for generations and is now consumed in many countries. It is sometimes spelled rooibosch in accordance with the old Dutch etymology.
In South Africa it is common to prepare rooibos tea in the same manner as black tea, and add milk and sugar to taste. Other methods include a slice of lemon and using honey instead of sugar to sweeten.
Several coffee shops in South Africa have recently begun to sell "red espresso", which is concentrated rooibos served and presented in the style of ordinary espresso. This has given rise to rooibos-based variations of coffee drinks such as red lattes and red cappuccinos. Iced tea made from rooibos has recently been introduced in South Africa, Australia, and in the United States. A variant of a London Fog, known as a Cape Town Fog, can also be made using Rooibos steeped in steamed milk with vanilla syrup.
Nutritional and health benefits
Rooibos is becoming more popular in Western countries, particularly among health-conscious consumers, due to its high level of antioxidants such as aspalathin[3] and nothofagin, its lack of caffeine, and its low tannin levels compared to fully oxidized black tea or unoxidized green tea leaves.[4] Rooibos also contains a number of phenolic compounds, including flavanols, flavones, flavanones, and dihydrochalcones.[5]
Rooibos is purported to assist with nervous tension, allergies and digestive problems.[6] Rooibos tea has been shown to inhibit in vitro activity of xanthine oxidase, yet an in vivo study has not been conducted. Xanthine oxidase (XO) plays a role in conversion of purine to uric acid in humans and reducing the activity of XO could limit uric acid production, which would aid in treatment of gout. In in vitro tests only, for the specific concentration tested, the tea was shown to be less than half as effective as allopurinol, which is the drug typically prescribed to inhibit XO activity in treating gout.[7]
Two rooibos flavonoids, quercetin and luteolin have been known to have cancer fighting qualities [8]. Rooibos does not contain the antioxidant Epigallocatechin-3-gallate (EGCG).[9]
Traditional medicinal uses of rooibos in South Africa include alleviating infantile colic, allergies, asthma and dermatological problems.[10][11]
Scientific study
Although human studies of rooibos are scarce in scientific literature, animal studies suggest it has potent antioxidant, immune-modulating and chemopreventive effects. In addition, no adverse side effects of consuming rooibos tea have been documented.[12]
It is often claimed that "Green" rooibos (see above) has a higher antioxidant capacity than fully oxidized rooibos. However, one study, using two different ways of measuring antioxidant activity, found conflicting data, with green rooibos showing more activity under one measure, and less activity using the other. The study also found conflicting data when comparing both forms of rooibos to black, green, and oolong tea, although it consistently found both forms to have less activity than green tea.[13]
In 2010, eleven poison dart frogs were raised at WWT Slimbridge by amphibian keepers in pint glasses of water, topped up with shop-bought Rooibos tea. Rooibos was used because it contains antioxidants with anti-fungal properties. This successfully protected the frogs against infection by chytridiomycosis.[14]
A recent study performed by Japanese scientists also suggests that Rooibos tea is beneficial in the topical treatment of acne.[citation needed] This is due to levels of alpha hydroxy acid, zinc and superoxide dismutase present in the herb.[citation needed]
In 2011, researchers conducted a trial to test the effects of rooibos on various biological markers considered to be indicative of risk for cardiovascular disease and other degenerative diseases. A high intake of rooibos tea resulted in significant reductions in lipid peroxidation, LDL cholesterol, triglycerides, and an increase in HDL cholesterol levels compared with the control group. The researchers concluded that rooibos improved risk factors.[15]