Impact of Chronic Consumption of Herbal Rooibos on Cardiovascular Function in Adults with Cardiovascular Risk

Abstract

The prevalence of cardiovascular disease (CVD) has increased in South Africa, emphasizing the importance of prevention strategies. This study used echocardiography to investigate the impact of Rooibos on cardiovascular function in those at risk of CVD. This research aims to contribute to understanding its effects on reducing cardiovascular risk factors. The study design involved a 12-week randomized, parallel, double-blinded, placebo-controlled dietary intervention trial using capsules containing standardized water-soluble extracts of green and traditional fermented Rooibos alongside a placebo control. Echocardiography was incorporated as a diagnostic imaging tool to assess cardiac function in the participant cohort. Aorta (AO) dimensions showed no significant change in any intervention group. Left atrium (LA) reduced in size from 3.832 ± 0.071 cm to 3.675 ± 0.067 cm (<i>P = 0.01</i>). There was no significant change in LA/AO ratio in any intervention group. Interventricular septum diameter in the placebo group decreased from 1.334 ± 0.030 cm to 1.250 ± 0.025 cm (<i>P = 0.002</i>), with no significance in fermented Rooibos, while green Rooibos resulted in a decrease from 1.282 ± 0.036 cm to 1.186 ± 0.029 cm (<i>P = 0.002</i>). Left ventricle posterior wall (LVPW) showed no significant changes in any of the intervention group. The left ventricle mass in the placebo and green Rooibos groups demonstrated no significance changes, while fermented Rooibos caused a decrease from 204.102 ± 7.102 g to 191.394 ± 6.707 g (<i>P = 0.015</i>). The phytochemical bioactive components, such as the polyphenolic antioxidants present in green and fermented Rooibos, improved cardiovascular function. This study confirms the effectiveness of echocardiography as imaging tool for assessing cardiac function in this particular population. Regular Rooibos consumption may offer promising therapeutic benefits for preventing and managing CVD risk.