Rooibos Extracts Demonstrate Protective Effects In Preliminary Breast Cancer Research
Issued by Meropa Communications on behalf of the SA Rooibos Council. For further information, please contact Brigitte Taim from Meropa on [email protected]
Rooibos, South Africa’s beloved herbal tisane, with proven benefits for the heart, diabetes management and brain health, is now revealing even more potential in preliminary breast cancer research led by Dr Nicky Verhoog, senior lecturer of biochemistry at Stellenbosch University.
Caption: Dr Nicky Verhoog, senior lecturer of biochemistry at Stellenbosch University.
Estrogen’s role in breast cancer
While the research is still in its early stages, initial findings suggest that Rooibos extracts may counteract the activity of estrogen in breast cancer cells – a discovery made possible through a collaboration between the South African Rooibos Council (SARC) and the Department of Science, Technology and Innovation (DSTI) Sector Innovation Fund Programme, which co-funded the original cell study.
This partnership did not only enable the cell study but was also instrumental in the decision to build on the findings resulting in SARC now funding the next phase of research in animal models, scheduled to begin next year.
Estrogen is often described as a kind of driver of breast cancer growth, because many breast cancer tumours carry receptors that respond to it. Although estrogen doesn’t always start the cancer, it can speed up its growth once the disease has developed. Some newer studies also show that it may sometimes play a more direct role in triggering changes in cells that lead to cancer. Because so many breast cancers are sensitive to estrogen, the possibility that Rooibos might help block its effect makes these findings especially significant.
Breast cancer in South Africa
Breast cancer remains a major health concern in the country. According to the latest statistics, between 11 000 and 15 000 women are diagnosed with breast cancer annually and the disease accounts for approximately 24% of all cancer cases in South African women. Early detection is critical – when identified at an early stage, breast cancer survival rates can exceed 90%, highlighting the importance of regular screening and self-examination.
Caption: Warning signs of breast cancer. Source: CANSA (cansa.org.za)
[1] chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.nicd.ac.za/wp-content/uploads/2025/04/NCR_ASR_tables_2023.pdf According to the National Cancer Registry (NCR), 10 980 cases of breast cancer were recorded in 2023...
[2] https://pmc.ncbi.nlm.nih.gov/articles/PMC10881925/
Rooibos under the microscope
Against this backdrop, Dr Verhoog’s team conducted an in vitro (cell) study to examine whether Rooibos could influence estrogen receptor-positive breast cancer cells...
“Rooibos appears to act in a protective way against estrogen-driven breast cancer cells in the lab. It doesn’t mimic estrogen but rather inhibits its action...
Next steps: animal trials in 2026
While the findings are promising, Dr Verhoog stresses the limitations of in vitro research...
Rooibos’ broader health benefits
Rooibos is already celebrated for its wide range of health benefits. Rich in antioxidants and free from caffeine and added sugars, it is a popular alternative...
With October recognised as Breast Cancer Awareness Month, the study also underscores the urgent need for continued scientific investigation...
Notes to editor:
- Dr Verhoog’s research is soon to be published in Planta Medica and The Journal of Ethnopharmacology.
