The health benefits of tea are constantly mentioned in the media and a lot of people seem to start drinking tea (especially green tea and herbal teas) for health reasons. So, from time to time, I gather and review the research that is published.
Rooibos is a caffeine-free tisane that comes from the leaf of Aspalathus linearis. Since it does not come from Camellia sinensis it is not a real tea so we call it a herbal tea or tisane. Traditional medicinal uses of rooibos have included alleviation of infantile colic, asthma, allergies, dermatological problems, digestive discomfort and anxiety.
Many studies have been done on the antioxidant content of Rooibos. Marnewick found that a 200ml serving of Rooibos has 58.5 – 68.9mg of pholyphenol antioxidants (depending on amount of leaves used and brewing time). Studies on the chemical constituents of the antioxidants in Rooibos have shown the presence of nothofagin, aspalathin and isoorientin, orientin, rutin and several other flavonoids and phenolic acids. The types of polyphenols in Rooibos are different to those in Green tea and Black tea and in particular, the antioxidant aspalathin can not been found in any other natural sources besides Rooibos. Researchers have found that “an aspalathin-enriched extract of green rooibos is able to lower raised glucose levels in the blood of diabetic rats” (source).
Two of Rooibos’s antioxidants (quercetin and luteolin) have been shown, in vitro, to induce the death of cancer cells (in vitro just means that the tests were carried out in a controlled environment outside a living body, e.g. in a test tube). Rutin has been found to prevent the formation of thrombosis (blood clots) in mice and orientin has been associated with a reducing damage to the bone marrow and gastrointestinal tract after mice were exposed to radiation.
Although, the antioxidant content of Rooibos is well documented and there are many laboratory results on the benefits of those antioxidants, I found it very difficult to find scientific, peer-reviewed articles on human studies involving Rooibos. One paper, published in the Journal of Ethnopharmacology, looked at the effect of Rooibos on specific parameters for adults at risk of developing heart disease. The results were positive and Rooibos significantly improved the lipid profile and the redox status. However, just 40 participants were involved in the study so presumably it would need to be repeated with a much larger group before it could be cited as conclusive evidence.
Rooibos has long been used to soothe colic in babies but the tea gained particular attention in the late 1960s when a South African woman, Annique Theron, found that it eased her infant’s colic. The story goes that she found no documentation on the benefits of Rooibos so she began her own experiments with babies who had colic and allergies. She concluded that Rooibos helped with the symptoms and she published a book in 1970 entitled “Allergies: An Amazing Discovery”. Rooibos seems to be still recommended by South African physicians in the treatment of colic even though the scientific evidence as a treatment does not seem to exist. Similarly, there is no scientific research into Rooibos as a treatment for skin allergies or digestive problems but its use as a treatment for both seem widely accepted.
So what’s the bottom line on the health benefits of Rooibos? Well, Rooibos is naturally caffeine-free, calorie-free, low in tannins and rich in antioxidants. Some lab and mouse work have been done on the specific benefits of the antioxidants in Rooibos but research on human models is scant. I think Ferreira et al put it best when he said “the growing body of evidence pointing towards the therapeutic value of Rooibos tea gives a considerable degree of credibility to the anti-ageing claims, but expectations of a healthier life rather than increasing lifespan would perhaps be a more realistic outlook”.