African rooibos red tea is made from an indigenous bush that grows in South Africa. Unlike black or green tea, African rooibos tea contains no caffeine, making it an alternative for those sensitive to caffeine's effects. The tea has also attracted attention because of claims of health benefits from regular consumption. While research does support some of these claims, the tea is not subjected to the rigorous testing of the U.S. Food and Drug Administration.
Improved Cholesterol Levels
Many of the health claims of rooibos tea involve its effects on cardiovascular risk factors such as cholesterol. High cholesterol can cause clots and heart attacks by narrowing the inner lining of blood vessels. Rooibos tea has demonstrated positive effects on blood cholesterol. A 2011 study by the Cape Peninsula University of Technology in South Africa found that consumption of rooibos tea over a six-week period increased levels of HDL, or good, cholesterol in participants while lowering rates of LDL, or bad, cholesterol.
Blood Pressure Treatment
Blood pressure is controlled through a complex series of reactions involving several chemical reactions in the body. One pathway involves the effects of an enzyme called angiotensin-converting enzyme, or ACE. ACE functions in constriction of blood vessels and release of hormones that affect blood pressure. A 2010 study by Linköping University in Sweden found that rooibos tea inhibited the activity of ACE, not unlike ACE-inhibitors prescribed to lower blood pressure.
Antioxidant Activity
Like other types of tea, African rooibos red tea has shown antioxidant activity. Antioxidants attack free radicals present in the body that can damage cells. Consumption of foods containing antioxidants may offer protection against stroke, cancer and atherosclerosis, according to the University of Maryland Medical Center. A 2009 study by Seikei University in Japan confirmed the antioxidant properties of rooibos tea due to its concentration of water-soluble polyphenols. Polyphenols are chemicals found in plants that can offer protection against some health conditions and aging.
Immune Function
Researchers have documented health benefits in other areas of body function, including the immune system. A 2001 study by Okayama University in Japan found that administration of rooibos tea extract in rats improved antigen-specific antibody production. Antigens are disease-causing substances that trigger antibody production. Based on the biological response, researchers recommended further investigation into specific immune responses involving cancer, allergy and AIDS.
References
- U.S. Food and Drug Administration: Dietary Supplements
- "Journal of Ethnopharmacology"; Effects of Rooibos (Aspalathus Linearis) on Oxidative Stress and Biochemical Parameters in Adults at Risk for Cardiovascular Disease; J. Marnewick, et al.; January 2011
- "Public Health Nutrition"; Effects of Green Tea, Black Tea and Rooibos Tea on Angiotensin-Converting Enzyme and Nitric Oxide in Healthy Volunteers; I. Persson, et al.; May 2010
- University of Maryland Medical Center: Vitamins - Dietary Health Benefits
- "Journal of Oleo Science"; Anti-Oxidative Effects of Rooibos Tea Extract on Autoxidation and Thermal Oxidation of Lipids; R. Fukasawa, et al.; May 2009
- "Bioscience, Biotechnology, and Biochemistry"; Effects of Rooibos Tea Extract on Antigen-Specific Antibody Production and Cytokine Generation In Vitro and In Vivo; K. Kunishiro, et al.; October 2001
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