Rooibos Shows Promise in Breast Cancer Research
- Oct 3
- 5 min read
PUBLISHED: 3 October 2025 | 5 MINUTE READ
Rooibos, South Africa’s beloved red herbal tea, has long been celebrated for its health benefits. From supporting heart health to helping manage diabetes and even boosting brain function. Now, preliminary research is revealing another exciting possibility: Rooibos may play a protective role in breast cancer.
Dr. Nicky Verhoog, senior lecturer of biochemistry at Stellenbosch University, is leading the way in uncovering how Rooibos extracts interact with breast cancer cells, and the results so far are both encouraging and hopeful for women everywhere.
Estrogen and Breast Cancer: Why It Matters
Estrogen, a natural hormone, plays an important role in women’s health. But when it comes to breast cancer, it can act as a driver of tumour growth. Many breast cancers are “estrogen receptor-positive,” meaning they respond to and are fueled by estrogen.
“Although estrogen doesn’t always start the cancer, it can speed up its growth once the disease has developed,” explains Dr. Verhoog. “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 early findings significant.
Breast Cancer in South Africa
Breast cancer is the most common cancer among South African women. Between 11,000 [1] and 15,000 [2] women are diagnosed every year, making up about 24% of all cancer cases. The good news? When detected early, survival rates can exceed 90%.
That’s why awareness, regular screening, and self-examination are so vital.
Rooibos Under the Microscope
To answer lingering questions about Rooibos and estrogen, Dr. Verhoog’s team conducted an in vitro (cell-based) study using well-established breast cancer cell models.
“To better understand how Rooibos interacts with natural hormones like estrogen, our team wanted to gather clearer scientific evidence,” says Dr. Verhoog. “We also looked at whether Rooibos could influence the growth and spread of cancer cells, which is especially important for women with hormone-sensitive breast cancer.”
Here’s what they discovered:
Rooibos extracts acted against estrogen, slowing down cell growth and preventing spread.
It worked in a way similar to fulvestrant, a drug used to block estrogen activity in breast cancer treatment.
Rooibos prefers activating ERβ, a receptor that suppresses tumour growth, instead of ERα, which fuels cancer.
Importantly, it did not interfere with tamoxifen, a standard breast cancer therapy.
“Rooibos appears to act in a protective way against estrogen-driven breast cancer cells in the lab,” notes Dr. Verhoog. “It doesn’t mimic estrogen, but rather inhibits its action. Importantly, we also found that it didn’t interfere with the effect of tamoxifen, which suggests Rooibos could be safely consumed by women undergoing treatment. Of course, this needs confirmation through in vivo (animal) studies.”
Next Steps: Moving Into Pre-Clinical Trials
While the findings are inspiring, they’re still early. Laboratory studies don’t fully replicate the complexity of the human body.
“Lab studies involve single cell types and don’t replicate the complexity of the human body,” says Dr. Verhoog. “We need to see how Rooibos behaves when metabolised in the body, which is why our next step is pre-clinical trials planned for 2026.”
These trials will explore Rooibos in animal models to confirm its safety for women with estrogen-sensitive breast cancer and better understand how it acts inside the body. The goal isn’t to position Rooibos as a treatment but to ensure women can enjoy it safely alongside conventional therapies.
Rooibos Beyond Cancer: Everyday Health Benefits
Even before these breast cancer studies, Rooibos was celebrated as a health-boosting drink. Naturally caffeine-free, sugar-free, and rich in antioxidants, it’s a perfect family-friendly alternative to sugary beverages.
Research has already highlighted its potential protective effects against other cancers (like prostate, liver, and colon), as well as benefits for heart health, diabetes management, and even cognitive support.
As Dr. Verhoog puts it: “While we are still in the early stages, our research adds to the growing evidence of Rooibos’ multifaceted biological actions. It’s a step toward understanding how this uniquely South African tisane may support health in a variety of ways.”
What This Means for You
While Rooibos won’t replace cancer treatment, these findings offer peace of mind for women who love their daily cup. Not only is it safe, but it may also hold protective properties worth celebrating as science continues to evolve.
And with October being Breast Cancer Awareness Month, this research is a timely reminder: prevention, early detection, and treatment save lives. Rooibos may one day play a supportive role, but for now, awareness is the most powerful tool we have.
Call to Action for Working Mamas
Get screened regularly – speak to your healthcare provider about mammograms and self-checks.
Know your family history – genetics play a big role in breast cancer risk.
Stay informed – follow updates from the South African Rooibos Council and the Cancer Association of South Africa (CANSA).
Enjoy your Rooibos – guilt-free and with even more appreciation for its unique health benefits.
[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. However, CANSA has highlighted significant underreporting, particularly in rural and under-serviced communities, suggesting that the actual number of cases is likely much higher. The available figures are based on pathological diagnoses.
The statistics provided by the International Agency for Research on Cancer (IACR) differ from those reported by the South African NCR, with the number of new breast cancer cases in 2020 being much higher in the IACR data than in the NCR data (15,491 versus 9259). These differences are due to the different strategies used to tally the statistics. The NCR is a collection of pathology-based cancer surveillance figures based on the curation of cancer diagnosis data from histology, cytology and bone marrow aspirate and trephine samples; these samples have been collected, analysed and then reported on annually [4]. The IACR data are based on the South African NCR and Eastern Cape Province Cancer Registries.
Rooibos Health Benefits at a Glance
Quick reasons to love your daily cup!
✅ Caffeine-free – gentle on the nervous system, safe for kids and during pregnancy.
✅ Rich in antioxidants – helps fight free radicals and supports cell health.
✅ Heart-friendly – may lower blood pressure and improve cholesterol levels.
✅ Blood sugar support – research shows it may help with diabetes management.
✅ Skin-loving – its anti-inflammatory properties can soothe eczema and acne.
✅ Brain boost – linked to reduced stress and improved cognitive function.
✅ Cancer research – early studies show promising protective effects in breast, prostate, liver, and colon cancers.
Tip for mamas: Swap one sugary drink a day for a cup of Rooibos — it’s hydrating, nourishing, and family-friendly.
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