Would you like to boost your intake of antioxidants and phytochemicals with a no calorie, no caffeine, delicious-tasting herb tea?
Consider red bush tea, also known as rooibos (roy-boss) or red tea. It is a member of the legume family of plants. Commonly called South African red tea, the product has been popular in South Africa for generations. It is now consumed in many countries with growing popularity in America. The flavor of rooibos tea is often described as being sweet even without sugar added. Long brewing improves its flavor even more. Red tea is often used as a popular ingredient in herbal tea blends.
Two Types of Rooibos
Rooibos comes from the leaves and stems of the Aspalathus linearis shrub which grows approximately five feet high and displays reddish-brown stems and bright green needlelike leaves. Fortunately for the rooibos plant, nitrogen-fixing bacteria inhabit the nodules of its roots thus enabling the plant to survive the nutrient-poor, acidic soils of the mountainous region in South Africa’s western cape.
There are two types of rooibos: red and green rooibos. Red rooibos comes from the oxidation of the leaves as they are cut and then sundried. Since the oxidation turns the leaves a red-orange color, the end product is used to make a red tea. Green rooibos tea does not involve an oxidation process. The end results are that the green tea has a yellow-tan color and possesses a milder taste. Unlike red rooibos, green rooibos tea is unfermented. Green rooibos has perhaps as much as 70% more of the beneficial phenolic phytochemicals as well as other antioxidants. Phenolic phytochemicals are biologically active compounds that exert potential disease-preventive activities.
Rooibos tea contains small amounts of iron, magnesium, phosphorus, sodium, chloride, potassium, and significant amounts of fluoride and copper. Copper is essential to the red blood cells. Fluoride strengthens the bones and teeth. Fortunately, unlike regular tea, red tea does not inhibit iron absorption because it is low in tannins.1 Tannins bind iron, reducing the absorption of non-heme iron. This can be a significant problem for individuals with marginal iron intake. In contrast, black and peppermint teas may inhibit iron as much 80 to 90%.2
Super Powerful Antioxidants
Rooibos is becoming more popular in Western countries, particularly amongst health-conscious consumers who appreciate it for its high level of powerful antioxidants and phytochemicals. Compared to green tea, rooibos tea has up to 50% more antioxidants and polyphenols. Rooibos tea is a good source of antioxidants due to its larger proportion of polyphenolic compounds.3 It contains large amounts of polyphenols which protect the cells from free radical damage and a naturally occurring enzyme, superoxide dismutase (SOD). Think of SOD as being one of the body’s foremost quenchers of free radicals. Moreover, SOD helps to regenerate another important a vitamin-like compound, CoQ10, which carries out several vital roles, including promoting energy production and neutralizing harmful free radicals.4
Animal studies suggest that rooibos exerts an anti-spasmodic effect on smooth muscle cells. It also exerts anti-spasmodic effects in the gut thereby reducing abdominal spasms and diarrhea.5 Chrysoeriol, a bioactive flavonoid in red tea, possesses antioxidant, anti-inflammatory, antimicrobial, antiviral, and free radical scavenging activities and has demonstrated bronchodilator effects.6
Certainly rooibos is worthy of further investigation as a potential therapy for bronchitis and other lung disorders. Red tea also contains an expectorant. Sipping red tea if you have a cough from bronchitis or a lower respiratory tract disorder might be beneficial. Studies indicate that rooibos has the potential to inhibit influenza A viruses. 7
Because it relaxes the smooth muscles in arteries and acts as a vasodilator, rooibos may also help to reduce elevated blood pressure.8 More investigation is warranted in human beings.
Dietary antioxidants have been shown to protect neurons against a variety of experimental neurodegenerative conditions such as Alzheimer’s and stroke.9
Rooibos helps to protect brain cells for certain effects of chronic stress. The antioxidant glutathione (GSH) is essential for the cellular detoxification of reactive oxygen species in brain cells. A compromised GSH system in the brain has been connected with the oxidative stress occurring in neurological diseases.10 Both physical and psychologic stressors deplete the brain’s level of glutathione. Rooibos restores the glutathione levels in the brain. (Hong)
Rooibos helps protect the brain from the effects of psychological stress. Chronic stress increases oxidative stress and accelerates the breakdown of protein in the brain. Early rodent studies indicated that red tea can ameliorate or offset degradation of protein in the brain. 11 Why is this important? The anti-depressant brain chemicals, nor-epinephrine and dopamine, are made from protein. Protein is required to produce a key neurotransmitter. Serotonin is one such major neurotransmitter involved in maintaining a positive outlook.
Rooibos contains alpha-hydroxy acid, known to promote healthy skin. When applied topically to the skin of rodents exposed to a carcinogen, extracts from red tea significantly reduced skin cancers. There is some evidence that red rooibos tea, when topically applied and also drunk as a beverage, can provide relief for people with eczema, dermatitis, and acne.
Green Rooibos & Diabetes
Studies on diabetic rodents suggest that aspalathin, a green rooibos tea flavonoid component, elevated blood glucose by stimulating its uptake into the muscle tissues and promoting insulin secretion from pancreatic beta-cells. These results also suggest that aspalathin has beneficial effects on glucose homeostasis in type 2 diabetes. Aspalathin reduces the gene expression of hepatic enzymes related to glucose production and lipogenesis.12 Additionally, aspalathin reduces the gene activity of enzymes in the liver related to endogenous glucose and fat production.13 More conclusive studies in humans are warranted. But if one has metabolic syndrome or prediabetes, a cup of organically grown green rooibos a day in addition to other lifestyle practices (plant-based, whole food diet, regular exercise twice a day, adequate exposure to sunlight and sleep, and regularity in schedule) might yield some positive benefits.
Green Rooibos & Diabetic Complications
Free radical damage and inflammation fuel the long-term complications of diabetes. Rooibos tea reduces oxidative stress in various tissues of the body (particularly the blood, the liver, and the lens of the eye). It significantly lowered advanced glycation end-products (AGES). AGES occur when glucose binds abnormally to protein so that cell proteins do not work well and even malfunction. AGES are big contributors to long-term complications from diabetes, neuropathy, kidney failure, lens damage, and diabetic retinopathy, a leading cause of blindness. They also interfere with the lungs so a person has more difficulty getting the air out as well as in. AGES can cause the connective tissues to lose their elasticity. Some investigators think that rooibos tea, as a commonly used beverage, can be recommended as “an excellent adjuvant support for the prevention and therapy of diabetic vascular complications and particularly for protecting the eyes.
Inflammation inside the arteries plays a major role in all the stages of the development of atherosclerosis and is a long-term complication of diabetes. Two phytochemicals in green rooibos suppress vascular inflammation.14
Help for the Liver
Red tea substantially increases the carcinogen-detoxifying enzyme, glutathione (GSH). Stress, obesity, toxins, drugs, and alcohol deplete the liver of glutathione. Rooibos counters this depletion and reduces oxidative stress in the liver. It is even more effective in this function when fresh lemon is added. Rodent studies reveal that rooibos returns elevated liver enzymes (indicating liver damage) to normal and can help to regenerate liver cells in rodents who have fibrosis of the liver.
Regularly eating a high fat diet (especially saturated and trans fats) increases body weight and fat content in the liver to an alarming extent. Hepatic steatosis is defined as intrahepatic fat of at least 5% of liver weight. If this condition is prolonged, it may lead to liver metabolic dysfunction, inflammation, and advanced forms of nonalcoholic fatty liver disease. Nonalcoholic hepatic steatosis is associated with obesity, type 2 diabetes, and dyslipidemia.15
Researchers fed rodents a high fat diet. These rodents were divided into two groups. One group just ate the high fat diet (HFD). The second group ate the same HFD but was given extracts from green rooibos tea (GRE). The volume and area of steatosis were significantly increased in the first HFD group while the area of steatosis was significantly reduced in the second group. These rodents in the second group eating the same high fat diet were concurrently treated with green rooibos extracts. More precisely, the percentage, location, and type of steatosis as well as presence of inflammation and hepatocellular injury were reduced in the GRE treated group although the diets were identical. These findings suggest that a GRE has potential as an anti-steatotic, anti-inflammatory, and weight reducing agent in vivo.16
In general, rooibos is very safe. Negative side effects are extremely rare; some have been reported. One case study found that drinking very large amounts of rooibos tea daily was linked to an increase in liver enzymes that can often indicate a liver problem. There isn’t enough reliable information to know if rooibos is safe to use when pregnant or breast-feeding so stay on the safe side and avoid use. Always check with your pharmacist before using any herb supplement if you are taking medicine to reduce your risk for possible undesirable drug-herb interactions. Avoid teas from China as they might be contaminated with lead.
Red tea is more than an enjoyable beverage. It is useful for respiratory ailments, brain and liver health, some gastrointestinal disorders, and especially as an antioxidant booster. More studies are needed to validate its uses and properties in humans. Rooibos can be served either as a beverage or used as a basis for soups, or mixed in fruit drinks. Because it is a good source of the trace minerals copper and fluoride, the authors would not recommend drinking more than a cup a day.
- 1Hesseling PB, et al., The effect of rooibos tea on iron absorption. S Afr Med J. 1979 Apr 14;55(16):631-2.↩
- Hurrell RF, et al., Inhibition of non-haem iron absorption in man by polyphenolic-containing beverages. Br J Nutr. 1999 Apr; 81(4):289-95.↩
- Hong IS, Lee HY, Kim HP. Anti-oxidative effects of Rooibos tea (Aspalathus linearis) on immobilization-induced oxidative stress in rat brain. PLoS One. 2014;9(1): e87061. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897768/ ↩
- Kucharská J, Regeneration of coenzyme Q9 redox state and inhibition of oxidative stress by Rooibos tea (Aspalathus linearis) administration in carbon tetrachloride liver damage. Physiol Res. 2004;53(5):515-21. PMID: 15479130. https://pubmed.ncbi.nlm.nih.gov/15479130/↩
- Gilani AH. Anti-spasmodic effects of Rooibos tea (Aspalathus linearis) is mediated predominantly through K+ -channel activation. Basic Clin Pharmacol Toxicol. 2006 Nov;99(5):365-73.↩
- Khan AU, Gilani AH. Selective bronchodilatory effect of Rooibos tea (Aspalathus linearis) and its flavonoid, chrysoeriol. Eur J Nutr. 2006 Dec;45(8):463-9. https://europepmc.org/article/med/17080260 ↩
- Rahmasaria R. Antiviral Activity of Aspalathus linearis against Human Influenza Virus. Nat Prod Commun. 2017 Apr;12(4):599-602. https://journals.sagepub.com/doi/abs/10.1177/1934578X1701200432↩
- Marques AAM. Nitric oxide and Ca2+-activated high-conductance K+ channels mediate nothofagin-induced endothelium-dependent vasodilation in the perfused rat kidney. Chem Biol Interact. 2020 Aug 25;327. https://pubmed.ncbi.nlm.nih.gov/32554038/ ↩
- Behl C, Moosmann B. Oxidative nerve cell death in Alzheimer’s disease and stroke: antioxidants as neuroprotective compounds. Biol Chem. 2002 Mar-Apr;383(3-4):521-36. https://europepmc.org/article/med/9565761↩
- Dringen R. Glutathione pathways in the brain. Biol Chem. 2003 Apr;384(4):505-16 https://www.researchgate.net/publication/10755344_Glutathione_Pathways_in_the_Brain ↩
- Hong IS, Lee HY, Kim HP. Anti-oxidative effects of Rooibos tea (Aspalathus linearis) on immobilization-induced oxidative stress in rat brain. PLoS One. 2014;9(1):e87061. Published 2014 Jan 21. https://pubmed.ncbi.nlm.nih.gov/24466326/ ↩
- Kawano A. Hypoglycemic effect of aspalathin, a rooibos tea component from Aspalathus linearis, in type 2 diabetic model db/db mice. Phytomedicine. 2009 May;16(5):437-43. https://pubmed.ncbi.nlm.nih.gov/19188054/↩
- Son MJ. Aspalathin improves hyperglycemia and glucose intolerance in obese diabetic ob/ob mice. Eur J Nutr. 2013 Sep;52(6):1607-19. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0216172 ↩
- Ku SK. Aspalathin and Nothofagin from Rooibos (Aspalathus linearis) inhibits high glucose-induced inflammation in vitro and in vivo. Inflammation. 2015 Feb;38(1):445-55. https://pubmed.ncbi.nlm.nih.gov/25338943/↩
- Nassir F. Pathogenesis and Prevention of Hepatic Steatosis. Gastroenterol Hepatol (N Y). 2015;11(3):167-175. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4836586/↩
- Layman JI, Pereira DL, Chellan N, Huisamen B, Kotzé SH. A histomorphometric study on the hepatoprotective effects of a green rooibos extract in a diet-induced obese rat model. Acta Histochem. https://pubmed.ncbi.nlm.nih.gov/31153588/↩