Rooibos (Aspalathus linearis) is a South African legume shrub, related to broom and clover, which traditionally only occurs in the wild in the Western Cape Province (Cederberg) northwest of Cape Town. Currently, the plant, which can grow to a height of 1.5 meters and has bright green needle-shaped leaves, is grown commercially in this region. Rooibos tea, tea made from dried leaves and twigs, was for a long time only known to the indigenous population, the Khoihoi (Hottentots) and the San (Bushmen). They used the watery infusion of rooibos not only to quench thirst but also to treat various ailments such as nervous tension, headaches, sleeping problems, inflammation, cardiac arrhythmias, high blood pressure, allergies (eczema, asthma), stomach complaints, nausea, diarrhea and intestinal cramps. The South Africans also used rooibos extract to add to the bath water of babies and small children with (allergic) skin complaints such as eczema, itching and rash. In colonial times, Dutch colonists drank rooibos tea to replace the expensive black tea, which had to be brought from Europe.

Some scientifically researched health effects of rooibos tea

Liver protection

Animal research has shown that rooibos tea improves antioxidant status in the liver. Rooibos tea significantly increased the activity of two important phase 2 detoxification enzymes (glutathione S-transferase alpha and UDP glucuronosyltransferase). In an animal model of oxidative liver damage and liver cirrhosis (administration of carbon tetrachloride), rooibos tea improved antioxidant status (coenzyme Q9, alpha-tocopherol) and decreased lipid peroxidation.5 Animal studies also found that treatment with rooibos tea led to a reduction in fatty liver disease and liver cirrhosis with marked improvement of liver function. The Czech researchers conclude that rooibos tea has a liver-protective effect and can best be recommended to people with liver disease.

Prevention of diabetes complications

In an animal model for type 2 diabetes, administration of rooibos extracts had no influence on the disease process itself (levels of glucose, HbA1c and fructosamine). However, rooibos tea did cause a significant decrease in AGEs (advanced glycation end products) and malondialdehyde (a measure of oxidative stress) in blood plasma and various tissues, including the eye lens. The researchers found that components in rooibos tea partly prevent oxidative stress in hydrophilic and hydrophobic biological systems. They think that rooibos tea can contribute to the prevention and treatment of diabetes complications (cataract, retinopathy, nephropathy, cardiovascular disease, neuropathy).

Reduction of gastrointestinal cramps and diarrhea

In South Africa, rooibos tea is traditionally used for nausea, gastrointestinal cramps and diarrhea; Intestinal colic in small children is also combated with rooibos tea. Experimental research confirms that rooibos tea has an antispasmodic, antidiarrheal and antisecretory effect. The (in vitro) relaxation of smooth muscle tissue (jejunum) by rooibos tea is the result of strong activation of K+ channels and slight inhibition of Ca++ channels in muscle cells; It has been shown (in-vivo) in laboratory animals that rooibos tea significantly inhibits diarrhea. The researchers calculated that the amount of rooibos probably needed to treat diarrhea in a 70 kg person is approximately 25 grams or 1.5 tablespoons.

For further investigation

• McKay DL et al. A Review of the bioactivity of South African herbal teas: Rooibos (Aspalathus linearis) and Honeybush (Cyclopia intermedia). Phytother Res. 2007;21:1-16.
• Erickson L. Rooibos tea: Research into antioxidant and antimutagenic properties. HerbalGram 59:33–45 (2003). http://content.herbalgram.org/wholefoodsmarket/herbalgram/articleview.as…
• Khan AU et al. Selective bronchodilatory effect of Rooibos tea (Aspalathus linearis) and its flavonoid, chrysoeriol. Eur J Nutr. 2006;45(8):463-9.
• Snijman PW et al. The antimutagenic activity of the major flavonoids of rooibos (Aspalathus linearis) – some dose-response effects on mutagen activation-flavonoid interactions. Mutat Res. 2007;613:111-123.