27 Feb 2013 Scientists continue to discover rooibos health benefits
At first it was assumed that it was the antioxidants in rooibos which protected against a range of diseases. More recent local and international studies have since found that it is not only the level of antioxidants, but also the specific combinations of bio-active compounds in rooibos that are important.
Scientists are still unravelling the complex pathways whereby the active compounds in rooibos can play a role in disease prevention, but studies have already shown that rooibos can help to reduce the risk of heart disease and stroke, boost the immune system, relieve allergies and prevent and slow cancer.
Recent studies have uncovered more benefits.
A group of Dutch researchers has demonstrated that rooibos has a strong antiviral activity against rotaviruses that cause serious infections, often with fatal consequences. The implications of this finding is significant as rotaviruses are a leading cause of severe, dehydrating diarrhoea in children under five and cause the deaths of nearly half- a-million each year.
Locally, a joint study by the Diabetes Discovery Platform of the Medical Research Council and the Agricultural Research Council’s Infruitec-Nietvoorbij Institute found evidence of rooibos’ anti-diabetic potential.
Working with diabetic rats, the researchers were able to show that a rooibos extract could achieve a glucose-lowering effect comparable to existing diabetic drugs.
This finding was supported by another study carried out at the Tokyo University of Agriculture and Technology. It confirmed that aspalathin – the unique flavonoid in rooibos – is able to help lower raised blood sugar levels and improve the metabolism of glucose.
The Japanese research team investigated the anti-diabetic action of aspalathin in living muscle cells and a diabetic mouse model which was able to shed light on the specific mechanisms involved at molecular and cellular level. Its results have been published in the December 2012 issue of the European Journal of Nutrition. (The abstract is available online at http://www.ncbi.nlm.nih.gov/pubmed/23238530.)
In another study, this time at Heidelberg University in Germany, scientists demonstrated that rooibos tea has the potential to promote longevity in living organisms. Using roundworms (Caenorhabditis elegans) as a model, they produced evidence that rooibos decreased oxidative damage in their cells. They were also able to show that aspalathin played a major role in their survival rate by targeting stress and ageing related genes.
Local researchers from the ARC and the University of Johannesburg are co-authors on the research paper published in the December 2012 issue of the scientific journal Phytomedicine. (The abstract is available online at http://www.ncbi.nlm.nih.gov/pubmed/23218401.)
“It is encouraging that international researchers are taking such an interest in South Africa’s herbal teas and that their findings held to improve our understanding of the health properties of rooibos tea,” says Prof Lizette Joubert, herbal tea expert at the Agricultural Research Council.
“This should provide further impetus to our efforts to understand the chemistry and biological properties of rooibos and other herbal teas so we will be able to advise people how to get the maximum health benefit.”
Source: South African Rooibos Council (www.sarooibos.org.za)