15 Aug 2012 Red or green rooibos? They’re both good, say researchers

“People should drink the kind of rooibos they enjoy most, since we now know that rooibos with a higher-antioxidant content does not always provide the best benefits,” recommends Prof Jeanine Marnewick, manager of the Oxidative Stress Research Centre in the Faculty of Health and Wellness Sciences at Cape Peninsula University of Technology.

Professor Marnewick, who has been actively involved in rooibos research over the last 15 years, explains that it is not only the level of antioxidants, but also the specific combinations of bio-active compounds in rooibos that are important.

“The health benefits from drinking rooibos tea will also be different for every person – depending on your overall health status,” she adds.

Scientists are still busy unravelling the complex pathways whereby the active compounds in rooibos can play a role in disease prevention, but several studies done on skin, liver, heart and oesophagus models, researchers have shown that traditional rooibos offers similar (and sometimes even better) health properties compared to green rooibos.

• Researchers at the Cape Peninsula University of Technology found that both traditional and green rooibos were able to protect and aid recovery of hearts tissue in rats following damage of the heart [1].
• A recent study at South Africa’s Medical Research Council showed that green and traditional rooibos could play a significant role in preventing or slowing done cancer of the oesophagus [2].
• A collaborative study in Europe showed that both green and fermented rooibos significantly increase the antioxidant capacity in human blood, thereby boosting the body’s natural defences [3].
• In an earlier study on skin cancer in mice researchers at South Africa’s Medical Research Council Found that traditional rooibos was even more effective than green rooibos at inhibiting cancer [4].

Much like making wine, making a good quality rooibos tea is both a science and an art. The characteristic colour and flavour of rooibos tea develops when enzymes that occur naturally in the plant turn the shredded green tea leaves reddish brown. This happens on the tea court while the moist tea is slowly dried in the sun. When making green rooibos, this step is skipped and the tea is dried as soon as possible in order to inactivate the enzymes in the plant and retain the green colour in the dried leaves.

References:

[1] rooibos (Aspalathus linearis) offers cardiac protection against ischaemia/reperfusion in the isolated perfused rat heart. W.G. Pantsi, J.L. Marnewick, A.J. Esterhuyse, F. Rautenbach, J. van Rooyen. Phytomedicine 18 (2011) 1220 – 1228.

[2] Modulating Effects of rooibos and Honeybush Herbal Teas on the Development of Esophageal Papillomas in Rats. Sissing, Linda , Marnewick, Jeanine , de Kock, Maryna , Swanevelder, Sonja , Joubert, Elizabeth and Gelderblom, Wentzel. Nutrition and Cancer, 63: 4, 600 — 610, 2 May 2011.

[3] Unfermented and fermented rooibos teas (Aspalathus linearis) increase plasma total antioxidant capacity in healthy humans. Débora Villaño, Monia Pecorari, Maria Francesca Testa, Anna Raguzzini, Angelique Stalmach, Alan Crozier, Claudio Tubili, Mauro Serafini. Food Chemistry: 123 (2016) 679-683, 2010.

[4] Inhibition of tumour promotion in mouse skin by extracts of rooibos (Aspalathus linearis) and honeybush (Cyclopia intermedia), unique South African herbal teas. Jeanine Marnewick, Elizabeth Joubert, Shamiel Joseph, Sonja Swanevelder, Pieter Swart, Wentzel Gelderblom. Cancer Letters 224; 193–202, 2005.