What Exactly Is Rooibos?
Often called 'red tea' or 'red bush tea', rooibos is not a true tea in the traditional sense. Unlike black and green teas, which come from the Camellia sinensis plant, rooibos is an herbal infusion made from the leaves of Aspalathus linearis, a shrub
grown exclusively in South Africa's Cederberg mountain region. For centuries, it has been a traditional beverage in southern Africa. The most common form is fermented, which gives the leaves their characteristic red-brown color and a naturally sweet, nutty flavour. There is also a green, unfermented version that is less processed and has a grassier taste. One of its biggest draws is that it's naturally caffeine-free and low in tannins, the compounds that can cause bitterness and interfere with iron absorption.
The Antioxidant Angle
Much of the buzz around rooibos centres on its antioxidants. These are compounds that help protect the body's cells from damage caused by free radicals. Rooibos contains several, including quercetin and luteolin, which are found in many fruits and vegetables. More uniquely, it's the only known natural source of aspalathin, a potent antioxidant. Green rooibos, being less processed, contains higher levels of these antioxidants than the more common red variety. While lab studies show these compounds have strong anti-inflammatory and antioxidant properties, the real-world impact is less clear. Some human studies have found that drinking rooibos can increase antioxidant levels in the body, but the effect is often small and temporary. The key question researchers are still exploring is whether we absorb enough of these compounds from a cup of tea to produce significant health benefits.
Heart Health: Promising but Preliminary
One of the most researched areas is rooibos's effect on cardiovascular health. Some studies suggest it may be beneficial. For example, rooibos may act as a natural angiotensin-converting enzyme (ACE) inhibitor, similar to some blood pressure medications, which helps relax blood vessels. A notable six-week clinical trial involving 40 adults at risk for heart disease found that drinking six cups of rooibos daily helped lower 'bad' LDL cholesterol and raise 'good' HDL cholesterol. Other research also points to a reduction in markers of oxidative stress linked to heart disease. However, it's important to frame these findings with caution. A 2023 review of 18 human studies concluded that while rooibos seems to improve lipid profiles and antioxidant status, the evidence is limited by a small number of total participants and inconsistent results across studies.
Diabetes and Blood Sugar Control
Another promising area of research is rooibos's potential role in managing type 2 diabetes. The unique antioxidant aspalathin has been the focus here. Lab and animal studies suggest that aspalathin may help improve insulin resistance and increase glucose uptake by muscles, leading to lower blood sugar levels. A meta-analysis of studies on diabetic rodents found that rooibos extracts were effective at reducing blood glucose. While these results are encouraging, the research has not yet made a significant leap from animals to humans. Large-scale human trials are needed to confirm if rooibos has the same blood-sugar-balancing effects in people. For now, it's considered a healthy, sugar-free beverage choice for people with diabetes, not a treatment.
Is It Safe for Everyone?
For the vast majority of people, rooibos is considered very safe to drink daily. Its caffeine-free nature makes it a great evening beverage or an alternative for those sensitive to stimulants. However, there are a few very rare considerations. A handful of case reports have linked excessive consumption—often in very large quantities—to elevated liver enzymes, so individuals with pre-existing liver conditions may want to exercise caution. Additionally, because some compounds in rooibos may have mild estrogenic activity, patients with hormone-sensitive cancers are sometimes advised to consult their doctor before making it a regular habit. Drug interactions, while not common, are also possible, particularly with medications for blood pressure and cholesterol. For most healthy individuals, moderate consumption of 3 to 6 cups per day is unlikely to cause any issues.
