Convenient Online Ordering

Please visit Miro Tea at Home to bring your Miro tea ritual to your space.
Our local community will have the choice of Free Hand Delivery or Free USPS shipping on qualifying orders!

facebook Twitter
menu left bg
menu left bg

Until now, my entries about rooibos have focused on the history, processing and especially on the delicious flavor of this unique bush. Today, I’d like to focus (in the most readable and accessible way possible) on the chemical composition and potential health benefits of rooibos.

Many people are aware that rooibos is naturally caffeine-free, but it’s somewhat less-known that the plant has a low tannin content and is full of polyphenols, minerals and flavonoids. In addition to containing the flavonoids rutin, orientin, iso-orientin, vitexin, iso-vitexin, luteolin, qurcetin, chrysoeriol, and nothofagin, rooibos contains a flavonoid–aspalathin–that is found nowhere else in nature. Rooibos also contains the minerals iron, potassium, calcium, copper, zinc, magnesium, fluoride, and manganese.

It’s pretty easy to toss off a list of minerals and impressive-sounding flavonoids, but this can be confusing for non-scientists (which describes most of us!) and, by itself, this list doesn’t really tell us anything concrete about the health benefits of rooibos. For years and years, rooibos drinkers have listed numerous health benefits, reporting that it slows aging, aids digestion, alleviates nausea, heartburn, ulcers and constipation, promotes bone and teeth strength, and is a mild relaxant good for drinking before bed. In the scientific and medical worlds, these types of reports are called “anecdotal evidence,” meaning that they may have merit, but are in no way scientifically-supported or produced. This is the dilemma scientists in South Africa were facing in the 1980’s, and a number of them resolved to close the gap and subject rooibos to scientific study, which began in 1990.

Scientific Studies: Animals
I recently had the privilege of listening to a presentation by Jeanine Marnewick, a South African scientist who has spearheaded the push for more scientific study of rooibos and its health benefits. I’d rather not get unnecessarily over-scientific about the results of the studies, so instead I’ll try to sum up the important points of the results.

Some of the first studies were conducted using rats. In one study, the scientists cut the hair from the rats’ backs, applied a rooibos solution topically to the rats’ skin, then applied a skin cancer initiator twice weekly for 20 weeks. Compared to the control group of rats that didn’t have the rooibos solution applied, the rooibos rats had dramatically-reduced instances of skin tumor development, including some rats with cancer-free skin and some with much more mild symptoms, such as decreased tumor size. A similar study showed that traditional rooibos arrested the growth of pre-cancerous lesions in rats’ livers, and green rooibos actually reduced the total number of pre-cancerous lesions, and in an esophageal cancer study, green rooibos significantly reduced the number and size of papillomas in the esophagi of the rats.

Two things must be noted when considering these studies. The first is that the objects of study are rats! Although the anti-cancer effects of rooibos in relationship to rats is exciting and promising, we have to remember that rats and humans are very different animals, and results of rat studies do not guarantee similar results with humans. The second is that, in the scientific community, before a health claim can become widely-accepted, that claim must be supported by a large body of evidence that has been approved by other scientists who work in the same field. A single study’s results are certainly not set in stone–another study could produce completely opposite results–and only after numerous studies produce similar results can people like me, an employee of the tea industry, begin confidently saying things like “Rooibos will prevent cancer.” Instead, it’s important to be honest about the cutting-edge information about rooibos health benefits, provide customers with the facts we have so far in proper context, and eagerly await more studies and more conclusive information.

Human Studies
Encouraged by the favorable animal studies involving rooibos, Marnewick and her associates recently (2007!) pushed ahead and began the first ever rooibos human health study. Since previous studies showed rooibos to have high antioxidant capabilities, Marnewick et al deduced that it would aid in the prevention of heart disease, which is often the result of oxidative stress–an imbalance between oxidants and antioxidants that can damage lipids, proteins, and DNA.

41 participants completed the study–26 females and 15 males–and all of them had at least one or more risk factors for developing heart problems within 10 years. The participants drank 6 cups of rooibos per day for 6 weeks and provided the scientists with blood and urine samples for study. The incomplete data analysis process for this study is very detailed, complicated, and lengthy, and results are only in an extremely preliminary stage. However, Marnewick has provisionally stated that rooibos has no apparent detrimental effects on the health of study participants and that it may prove to decrease oxidative damage to blood lipids.

At first glance, these results may not seem very impressive, but with a little perspective, they’re pretty exciting. If, when all of the lab analysis is completed, the provisional conclusions are verified, then the likelihood that more and more rooibos human health studies will be conducted is very good. With an increased body of results and evidence relating to rooibos health benefits, we can more confidently confirm or deny the anecdotal evidence that has been floating around for quite a while. Most excitingly, we get to witness the scientific study of rooibos health benefits in its nascent stages. This first study is only the tip of the iceberg when it comes to what we can learn about rooibos, and hopefully it is the first of many (including ones with larger participant bases and stronger control measures) that we can reference when discussing rooibos as a healthy beverage option. For now, we can mainly refer to this information in a tentative way, making sure to note that the study of rooibos health benefits are in very beginning stages. At the very least, though, these early studies are pointing in a promising and exciting direction.

Since the final results and analyses are not completed, this study is not up for online access at this point. If you google Jeanine Marnewick, though, you’ll get a lot of results relating to past studies about rooibos (including the rat studies mentioned above) as well as other infused beverages. I hope this info was helpful, understandable, and not too complicated. As usual, I’m happy to field any questions (though scientific health studies aren’t really my specialty!).

This post wraps up the festivities for Rooibos Month at Miro Tea, though our specials and promotions will last until the beginning of July–Chinese Green Tea month! Stay tuned for some exciting happenings involving Chinese green tea, including detailed fresh 2008 tea tasting notes, tasting events, and more specials and promotions!


Many people are well-acquainted with that most classic of summer beverages–the Arnold Palmer. Named after golf legend Arnold Palmer, it’s a textbook example of what happens when you combine two tasty summer beverages (iced tea and lemonade); pure, unadulterated
deliciousness. At Miro Tea, we call the Arnold Palmer the “Arnie,” and in celebration of Rooibos Month, we’ve put a new spin on this classic thirst-quencher: the “Ernie!”

This mouth-watering iced tea fusion combines Rooibos–the South African red bush–with lemonade and just a touch of honey water for an added boost. It’s extra thirst-quenching because rooibos is naturally caffeine-free, and it’s on sale at a special promotional price of $2.75 for the month of June. Best yet, it’s named after another famous golfer–Ernie Els–who hails from the same country as rooibos! It was meant to be…


Even avid rooibos drinkers may not know that the bushes’ needle-like leaves actually aren’t the same color as the finished product that we drink. In reality, the plant looks like your average bush (pictured R). Really, it’s the processing that results in the deep redness of traditional rooibos.

Rooibos bushes are generally harvested during the African summer, between January through March, during which the bushes are cut to a height of approximately one foot and the needle-like leaves are processed one of two ways: If the leaves and stems of the bush are dried directly after being cut and crushed, the product is green rooibos (pictured below), which is a light tan color and has a mild “green” flavor, slightly reminiscent of green tea. Perhaps due to the health claims surrounding green tea (especially versus black tea), there are many unsupported claims that green rooibos possesses more antioxidants and health benefits than traditional rooibos.
If the crushed and cut leaves and stems are bruised, heaped and exposed to oxygen before being dried, they will oxidize and take on the red color and signature aroma of traditional rooibos. Historically, the indigenous Khoisan people of South Africa accomplished this process by pounding the rooibos leaves with wooden mallets. These days, the crushing, cutting and bruising is performed by machines. Although some sources refer to the oxidation process as “fermentation,” the term is technically incorrect when used to describe rooibos since enzymes specific to rooibos bring about the process when exposed to oxygen. After drying, the leaves are sorted and graded according to length, color, flavor and aroma, and steam pasteurized before domestic consumption or export. The highest grade of rooibos is referred to as “supergrade;” other leaf styles are marketed as well, such as “long leaf” variety.

At Miro Tea, we offer both traditional and green rooibos in unblended as well as blended, scented and flavored varieties, so if you’re after antioxidants, you can have them all!


This June at Miro Tea, we’re celebrating Rooibos, the South African red bush. Although it’s not a true “tea” (rooibos comes from the Aspalathus linearis plant, not the Camellia sinensis), this special bush produces delicious, world-famous beverage when infused in hot water. To celebrate rooibos month, we at Miro Tea have a few events planned:

  • All rooibos beverages and loose leaf bulk purchases get a 15% discount!
  • We’re offering free samples of loose rooibos for customers to try at home!
  • We’ll be serving “The Ernie,” a special iced rooibos beverage (to be introduced next entry), all month!
  • Informational rooibos handouts are available at the store, and I’ll be posting informational articles about rooibos’ processing and health benefits as well.

If you’ve never tried rooibos, you’ve been missing out on quite a treat. June is the perfect month to enjoy this naturally caffeine-free, healthy beverage–it’s delicious both hot and iced.

If you haven’t already, check out this earlier post about the origin of rooibos as a cultivated crop.

More to come…


Many people are very familiar with the smooth, naturally sweet flavor and highly-concentrated health benefits of rooibos, the South African red bush, but far fewer people have probably heard about the beginning of its life as an internationally-traded commodity. Although it’s been consumed by the indigenous Khoisan people of what’s now known as the Cederberg region of South Africa for hundreds (perhaps thousands) of years, rooibos (pronounced “roy-boss”) has only been cultivated commercially since the early 20th century. I’d like to share one of the most interesting parts of the rooibos story:

Benjamin Ginsberg, a Russian settler of South Africa, was the first person to develop rooibos as a product. In the 1930s he enlisted the aid of a local doctor and hobby scientist, Peter Nortier, in order to begin cultivation of the plant, which had previously been harvested wild. The only problem, though, was finding seeds–rooibos seeds are housed in small pods. When each pod is ripe, it will burst open, scattering the tiny seeds on the ground around the plant (which is usually sandy). Usually the rooibos pods on a particular bush reach maturity at different rates, so it might also take quite a while for all of a plant’s pods to burst. Nortier eventually had to resort to paying local farmers and villagers to collect the seeds for him: a shilling for a matchbox full of rooibos seed. One Khoi woman came back more than anyone else–multiple times per day. Eventually, she divulged her secret:

Rooibos (an ant’s eye view)

One day, she had noticed a certain type of black ant carrying rooibos seed back to their colony. Breaking open the nest, she discovered an ant granary full of seed! Eventually, commercial rooibos cultivation took off, but it probably wouldn’t have been possible without the initial efforts of Ginsberg, Nortier, and the Khoi woman who discovered a way around painstaking seed collection–let the ants do the work! Today, rooibos seeds are collected by a special sifting process that lifts the seeds from the sandy soil around the plants, but some farmers still rely on exploiting the free labor of those rooibos seed-loving black ants.