A recent study from the Applied Microbial and Health Biotechnology Institute at the Cape Peninsula University of Technology (CPUT) has shed light on the potential heart health benefits of Rooibos tea.

Led by Prof. Jeanine Marnewick and researcher Maria Hartnick, the research builds on previous findings that suggested Rooibos could help manage risk factors for cardiovascular disease (CVD).

This latest study takes a novel approach by employing advanced diagnostic techniques to assess real-time heart function in individuals at risk for CVD. The researchers aimed to investigate how Rooibos impacts cardiovascular function, moving beyond previous studies that primarily focused on biochemical markers.

“We wanted to delve deeper into how Rooibos affects the actual functioning of the heart,” said Prof. Marnewick.

The team utilized transthoracic echocardiography—a diagnostic ultrasound technique—allowing them to monitor the heart’s activity in real time for the first time in Rooibos research.

The study involved male and female participants with at least two modifiable CVD risk factors, such as high blood pressure or elevated cholesterol. Over 12 weeks, participants consumed the equivalent of six cups of either fermented (red) or unfermented (green) Rooibos daily. Promising results showed significant reductions in key cardiovascular parameters, including left atrium size, interventricular septum thickness, and left ventricular mass, particularly with green Rooibos.

These changes suggest improvements in cardiac structure and function, indicating better endothelial health and overall cardiovascular well-being. Hartnick noted, “These reductions are a positive sign, reflecting potential enhancements in heart health.”

A unique aspect of this study was its focus on whole Rooibos rather than isolating individual compounds. The researchers used a water extract to mimic a typical cup of tea, making the findings more relevant to everyday consumption. While previous studies identified antioxidants like aspalathin and nothofagin in Rooibos, this research emphasizes the beverage’s overall health benefits.

The study employed a robust randomized, placebo-controlled, parallel design, marking a departure from earlier crossover studies. This allowed for comprehensive echocardiographic measurements, enhancing the validity of the findings. “We followed strict guidelines from the American Society of Echocardiography to ensure accuracy,” Hartnick explained.

Among the study’s key findings, the significant reduction in left atrium size and other critical markers of hypertensive heart disease was highlighted. Prof. Marnewick described these results as a major breakthrough, stating, “It’s the first time we’ve been able to show these effects in humans.”

While the researchers caution that more investigation is needed to understand the clinical implications fully, they believe Rooibos could be a valuable preventive strategy for cardiovascular health. “Regular consumption of Rooibos may help reduce the incidence of CVD,” Hartnick suggested, underscoring its potential role in public health.

Prof. Marnewick envisions this research influencing future dietary guidelines, particularly in regions where Rooibos is widely available. “As a natural, low-cost intervention, Rooibos could contribute to broader strategies aimed at improving cardiovascular outcomes,” she said.

Moving forward, the team plans to explore the long-term effects of Rooibos on heart health. “We’ve established a foundation with this study, but there’s still much to learn,” added Prof. Marnewick. In the meantime, Rooibos enthusiasts can enjoy their favourite brew with the knowledge that it may be supporting their heart health.