Loading...
Modulation of cardiovascular function by rooibos in adults at risk for cardiovascular disease
Author(s)
Hartnick, Maria Diana
Date Issued
2024
Type
Thesis
Publisher
Cape Peninsula University of Technology
Abstract
Introduction: Cardiovascular disease (CVD), diabetes and stroke collectively represent the
second leading cause of mortality among South African adults. These non-communicable
diseases pose a significant global health threat, emphasising the importance of adopting and
maintaining a healthy lifestyle with optimal dietary habits. Failure to address this issue will
likely result in a substantial increase in the burden of non-communicable diseases (NCDs) in
South Africa in the coming decades. In 2017, coronary heart disease and stroke emerged as
the predominant non-communicable disease (NCD) globally and resulted in an estimated 17.8
million fatalities, with over 75% of these fatalities occurring in low-income and middle-income
countries. This fact underscores the critical need for further investigation and interventions in
the field of cardiovascular health. One of the root causes underlying many non-communicable
diseases, including CVD, cancer, and diabetes, is a redox imbalance resulting in ‘chronic’
oxidative stress. To mitigate these risks and potentially enhance the quality of life and lifespan,
the utilisation of bioactives, such as antioxidants to support the redox balance, is imperative.
Aim: This research aims to determine the prevalence and characteristics of CVD and its
associated risk factors in a South African cohort, assess the impact of Rooibos (Aspalathus
linearis) on cardiovascular function in adults at risk for CVD using Transthoracic
Echocardiography (TTE), and establish an association between CVD findings and dietary interventions.
Method: Using a randomised, placebo-controlled parallel design, this study investigated the
impact of regular consumption of two types of Rooibos on key cardiovascular parameters
using TTE. The cohort of participants (n=219) included three parallel groups that were
matched according to age and gender. They were randomly assigned to consume either the
placebo or fermented Rooibos, or green Rooibos. The Rooibos capsules contained
standardised water-soluble extracts, and participants were requested to consume one capsule
(equivalent to two cups of Rooibos herbal tea) three times a day with meals (morning, midday,
and evening) for 12 weeks. Cardiovascular function was assessed using TTE. All
echocardiograms were performed according to the American Society of Echocardiography
(ASE) guidelines, standards and recommendations.
Results: Objective 1: The results indicate that the population was moderately obese: Body
Mass Index (BMI) = 31 kg/m²; the average systolic blood pressure (SBP) = 131 mmHg;
average diastolic blood pressure (DBP) = 84 mmHg; total serum cholesterol = 5.5 mmol/l;
fasting plasma glucose = 4.51 mmol/L, within normal limits. Of the 219 participants, 118
(53.9%) were at a lower risk for cardiovascular disease, and 101 (46.1%) were at a higher risk
for cardiovascular disease. Objective 2: The effect of daily Rooibos consumption over 12 weeks on the cardiovascular system included the following outcomes: grade 1 diastolic
dysfunction counts decreased from 63 (28%) to 47 (21.5%), grade 2 diastolic dysfunction
decreased from 46 (21%) to 24 (11%) and grade 3 diastolic dysfunction decreased from 5
(2.3%) to 3 (1.4%). There was no effect on the aortic size (AO) in all the intervention groups,
while the left atrium (LA) significantly (p=0.01) decreased in size from 3.83 cm ± 0.07 cm to
3.68 cm ± 0.07 cm. The LA / AO ratio did not change significantly in all the intervention groups.
Interventricular septum diameter (IVSd) in the placebo group decreased significantly
(p=0.002) from 1.33 cm ± 0.030 cm to 1.25 cm ± 0.03 cm with no positive change in the
fermented rooibos group, while the green rooibos group demonstrated a significantly
(p=0.002) decreased diameter from 1.28 cm ± 0.04 cm to 1.19 cm ± 0.03 cm. In all three
intervention groups no significant changes for the left ventricle posterior wall (LVPWd) were
detected. The placebo (p=0.300) and green rooibos (p=0.292) groups demonstrated no
significant changes for the left ventricle mass (LVM), while the fermented rooibos group
showed a significant (p=0.015) decreased mass (from 204.1 g ± 7.1 g to 191.4 g ± 6.7 g). No
significant positive changes were seen in all the groups with regard to the left ventricle in
diastole diameter (LVIDd), left ventricle in systole diameter (LVISd) and the ejection fraction
(EF).
Conclusion: In general, this study reveals evidence suggesting that the regular consumption
of Rooibos may be associated with cardiovascular protective effects, with specific focus on
the left atrium (LA), interventricular septum (IVS) and left ventricular mass (LVM). These
findings underscore the potential benefits of incorporating Rooibos into the daily dietary habits
as a means to promote heart health and reduce the risk for cardiovascular diseases. Further
research and clinical investigations are warranted to elucidate the precise mechanisms
underlying these protective effects and to explore the long-term implications of Rooibos
consumption on overall cardiovascular well-being.
second leading cause of mortality among South African adults. These non-communicable
diseases pose a significant global health threat, emphasising the importance of adopting and
maintaining a healthy lifestyle with optimal dietary habits. Failure to address this issue will
likely result in a substantial increase in the burden of non-communicable diseases (NCDs) in
South Africa in the coming decades. In 2017, coronary heart disease and stroke emerged as
the predominant non-communicable disease (NCD) globally and resulted in an estimated 17.8
million fatalities, with over 75% of these fatalities occurring in low-income and middle-income
countries. This fact underscores the critical need for further investigation and interventions in
the field of cardiovascular health. One of the root causes underlying many non-communicable
diseases, including CVD, cancer, and diabetes, is a redox imbalance resulting in ‘chronic’
oxidative stress. To mitigate these risks and potentially enhance the quality of life and lifespan,
the utilisation of bioactives, such as antioxidants to support the redox balance, is imperative.
Aim: This research aims to determine the prevalence and characteristics of CVD and its
associated risk factors in a South African cohort, assess the impact of Rooibos (Aspalathus
linearis) on cardiovascular function in adults at risk for CVD using Transthoracic
Echocardiography (TTE), and establish an association between CVD findings and dietary interventions.
Method: Using a randomised, placebo-controlled parallel design, this study investigated the
impact of regular consumption of two types of Rooibos on key cardiovascular parameters
using TTE. The cohort of participants (n=219) included three parallel groups that were
matched according to age and gender. They were randomly assigned to consume either the
placebo or fermented Rooibos, or green Rooibos. The Rooibos capsules contained
standardised water-soluble extracts, and participants were requested to consume one capsule
(equivalent to two cups of Rooibos herbal tea) three times a day with meals (morning, midday,
and evening) for 12 weeks. Cardiovascular function was assessed using TTE. All
echocardiograms were performed according to the American Society of Echocardiography
(ASE) guidelines, standards and recommendations.
Results: Objective 1: The results indicate that the population was moderately obese: Body
Mass Index (BMI) = 31 kg/m²; the average systolic blood pressure (SBP) = 131 mmHg;
average diastolic blood pressure (DBP) = 84 mmHg; total serum cholesterol = 5.5 mmol/l;
fasting plasma glucose = 4.51 mmol/L, within normal limits. Of the 219 participants, 118
(53.9%) were at a lower risk for cardiovascular disease, and 101 (46.1%) were at a higher risk
for cardiovascular disease. Objective 2: The effect of daily Rooibos consumption over 12 weeks on the cardiovascular system included the following outcomes: grade 1 diastolic
dysfunction counts decreased from 63 (28%) to 47 (21.5%), grade 2 diastolic dysfunction
decreased from 46 (21%) to 24 (11%) and grade 3 diastolic dysfunction decreased from 5
(2.3%) to 3 (1.4%). There was no effect on the aortic size (AO) in all the intervention groups,
while the left atrium (LA) significantly (p=0.01) decreased in size from 3.83 cm ± 0.07 cm to
3.68 cm ± 0.07 cm. The LA / AO ratio did not change significantly in all the intervention groups.
Interventricular septum diameter (IVSd) in the placebo group decreased significantly
(p=0.002) from 1.33 cm ± 0.030 cm to 1.25 cm ± 0.03 cm with no positive change in the
fermented rooibos group, while the green rooibos group demonstrated a significantly
(p=0.002) decreased diameter from 1.28 cm ± 0.04 cm to 1.19 cm ± 0.03 cm. In all three
intervention groups no significant changes for the left ventricle posterior wall (LVPWd) were
detected. The placebo (p=0.300) and green rooibos (p=0.292) groups demonstrated no
significant changes for the left ventricle mass (LVM), while the fermented rooibos group
showed a significant (p=0.015) decreased mass (from 204.1 g ± 7.1 g to 191.4 g ± 6.7 g). No
significant positive changes were seen in all the groups with regard to the left ventricle in
diastole diameter (LVIDd), left ventricle in systole diameter (LVISd) and the ejection fraction
(EF).
Conclusion: In general, this study reveals evidence suggesting that the regular consumption
of Rooibos may be associated with cardiovascular protective effects, with specific focus on
the left atrium (LA), interventricular septum (IVS) and left ventricular mass (LVM). These
findings underscore the potential benefits of incorporating Rooibos into the daily dietary habits
as a means to promote heart health and reduce the risk for cardiovascular diseases. Further
research and clinical investigations are warranted to elucidate the precise mechanisms
underlying these protective effects and to explore the long-term implications of Rooibos
consumption on overall cardiovascular well-being.
Additional information
Thesis (Doctor of Radiography (Ultrasound))--Cape Peninsula University of Technology, 2024
File(s)![Thumbnail Image]()
Loading...
Name
Maria_Hartnick_192055836 DRad Thesis.pdf
Size
6.73 MB
Format
Adobe PDF
Checksum
(MD5):5ab7a0aaea7866026aefeb16a1e8089b