Effects of rooibos (Aspalathus linearis) on risk for cardiovascular disease

BEDTIME BOOST:A cup of rooibos tea could be the answer to sleepless nights.

According to the Heart- and Stroke-foundation of South Africa (HSFSA) one in five deaths in South Africa is caused by cardiovascular diseases, and this is the reason for approximately 82,000 deaths every year.  The incidence is on the increase amongst all population groups in South Africa, and medical scientist and medical doctors are on the lookout for new methods to treat and prevent this serious health problem.

Although Western medicine was very successful to treat serious medical and surgical emergencies, the same cannot be said for the management of the chronic and degenerative diseases such as cardiovascular disease, osteoporosis, cancer, arthritis and neuro-degenerative disorders.  The treatment of these diseases is not only costly, but may have serious side effects, and may only offer symptomatic relief.  Disillusioned patients often visit alternative- and complimentary-practitioners for solutions for their health problems, often with disappointing results.

There is a movement in mainstream medicine towards prevention rather than cure.  It is estimated that almost 80% of cardiovascular disease can be prevented with a heathy lifestyle. The causes of heart attacks and stroke are multifactorial, and a holistic approach is necessary to address all the risk factors involved in the development of cardiovascular disease.   Risk factors such as age, gender, family history and genetics are not modifiable, and factors such as living conditions, poverty and pollution are difficult to change.  Modifiable risk factors include exercise, weight management, healthy diet, no smoking, excessive alcohol consumption and stress are the focus of holistic medical practitioners.  Doctors integrate various alternative and complementary treatment options where there is scientific evidence for efficacy.  These Integrative medical practitioners have a patient-centred approach rather than a disease-centred approach, where the patient accepts some responsibility for their health.  The treatment concentrates on the stimulation of healing rather than just the relief of symptoms.  The body has the capacity to heal itself, provided that the circumstances are favourable.

Interest in the importance of diet and lifestyle was sparked after the publication of the article on the “French paradox” in the late 1980’s.  Doctors realized that a diet rich in plant foods (including a glass of red wine) , and relatively rich in saturated fats, is in apparent contradiction to the widely held belief that the high consumption of such fats is a risk factor for CHD.  This diet may play a role in the prevention of heart disease.  Fruit and vegetables contains many phyto-chemicals such as antioxidants that may be responsible for these protective effects.  A plant-based diet is also alkaline as opposed to a diet rich in animal protein which is acidogenic.  The benefits of an alkaline diet are becoming apparent in the prevention of cancer and osteoporosis.

The effect of rooibos herbal tea on cardiovascular diseases have been investigated by researchers in South Africa and Sweden, and revealed interesting results.  Rooibos is naturally caffeine free, contains low levels of tannins and is an important dietary source of antioxidants.  Observational studies linking high dietary intake of plant foods and beverages with a lower incidence of cardiovascular and other chronic diseases suggest the association may be attributed to the polyphenolic antioxidants in these foods.  Rooibos has also been shown to be antimutagenic and cancer modulating which adds to the health benefits of this beverage.

Drinking tea has been reported to positively modulate the lipo-protein profile by decreasing the LDL-cholesterol levels and increasing the HDL-cholesterol level.  This study provides the first clinical evidence in humans that chronic consumption of rooibos improved several biomarkers of blood lipid status. It is interesting to note that drinking tea can increase the HDL-cholesterol in the same way as moderate alcohol consumption. The modulation of the cholesterol status with diet modulation is an important finding, because the current cholesterol-lowering agents (statins) is not only expensive, but may have serious side effects.  Doctors emphasize natural interventions such as diet modification, weight management and exercise to increase the ‘good’ HDL-cholesterol, and to lower the ‘bad’ LDL-cholesterol as the first line of treatment for abnormal blood lipids.

A recent study in Sweden indicated that the oral intake of a single dose of Rooibos tea significantly inhibited angiotensin-converting enzyme (ACE).  ACE inhibitor-drugs have a blood pressure-lowering effect, and are the first-line treatment of hypertension and thus a common drug used for cardiovascular disease. These results suggest that Rooibos tea may have cardiovascular effects through inhibition of ACE activity.  Intake of high amounts of flavonoids, i.e. tea, vegetables and fruits, might contribute to the prevention of cardiovascular disease by lowering the blood pressure in the population and thereby prevent cardiovascular mortality.

An important observation was that rooibos did not affect iron absorption, in contrast to black tea that showed significant reduced iron uptake.  This is considered to be due to the low tannin content of rooibos compared to black teas.  Since iron-deficiency anaemia is the most common deficiency disease in the world, this is a significant health benefit.  Rooibos tea does not inhibit the bioavailability of dietary non-haem iron, and may thus play a role in the prevention of anaemia in the general population.

Health conscious people drinking rooibos tea usually follow a healthy lifestyle, and include exercise, no smoking, weight- and effective stress-management techniques in their daily routine.  Because of the multifactorial causes of cardiovascular disease, it is necessary to have a holistic approach by taking all the risk factors into consideration to prevent this serious health threat.  Rooibos tea on its own will have a minimal effect on cardiovascular mortality if the other modifiable risk factors are not addressed appropriately.

In conclusion, there is good reason to believe that rooibos tea may reduce cardiovascular mortality. Several positive effects of tea on the cardiovascular system have been shown: reduction of atherosclerosis and lipid peroxidation, anti-inflammatory properties, and improvement of endothelial function.  Medical practitioners will have to focus more on natural interventions in the management of chronic and degenerative diseases such as heart disease and stroke.  Rooibos tea has an important role to play in this regard as it is a unique South African beverage, and the consumption is growing in popularity because of the many health benefits associated with this herbal tea.

David van Velden, MB ChB, M Prax Med, M Phil (Journalism) was head of the Department of Family Medicine at the University of Stellenbosch, South Africa