The Biology of Rooibos (South African Red Tea) – Climate Change And Health Effects

This article focuses on Rooibos, a plant used to produce a drink known as South African red tea, or just red tea, not to be confused with the Chinese term “red tea” which refers to what Westerners call “black tea”. Rooibos also refers to a caffeine-free herbal tea made from the Aspalathus linearis plant.

Basics of Aspalathus linearis:

Aspalathus linearis, or rooibos, is a legume, meaning that it is in the same family as beans, peas, and locust trees. Like most legumes, this plant is a nitrogen fixer. This means that the Aspalathus linearis plant is able to take atmospheric nitrogen and transform it into a form that it and other plants are able to use. The plant does so by means of special nodules in its roots that create an oxygen-free environment, where anaerobic bacteria are able to convert the nitrogen from air into forms usable by living organisms. Nitrogen-fixing plants are essential in many ecosystems, as they represent the primary source through which nitrogen enters the ecosystem. These plants typically fix far more nitrogen than they are able to use themselves, and thus benefit numerous other plants.

Rooibos is native to a small region of South Africa’s West Cape Province. This area has a semi-arid climate. Unfortunately, efforts to cultivate rooibos outside this region have so far proved unsuccessful. The plant seems to be dependent on the unique conditions in this region.

Rooibos and climate change:

Rooibos is among the commercial crops most threatened by climate change, primarily due to the particular range of conditions that the plant requires. Global climate change threatens not only to change the temperature worldwide and in this region, but to create other little-known and possibly unpredictable changes in climate in this region.

Rooibos and positive health effects:

Rooibos is used extensively in traditional medicine, but it is only beginning to be studied and understood scientifically. However, it shows promise of considerable positive effects on health. One chemical in rooibos, lutein, is a common chemical in numerous plants. Lutein is a carotenoid, a reddish pigment contributing to the red color of rooibos. It also functions as an antioxidant and radical scavenger, and is likely responsible for some of the observed effects of rooibos in animal studies, such as protecting against radiation poisoning. The same chemical which helps to protect the rooibos plant against the sun’s ray’s can also protect humans as well, when they drink the plant as an herbal tea. Rooibos is also used in skin products, and shows some evidence of sun-protective effects.

Rooibos also shows evidence of other positive health effects. One study in rats found evidence that it acts as a bronchodilator, helping to facilitate breathing, like many medications used to treat asthma.

In summary:

Rooibos is a nitrogen-fixing legume native to a small region of the West Cape Province of South Africa. Its production is limited to this area, and is vulnerable to climate change. Rooibos has numerous positive effects on health, which are only beginning to be thoroughly studied and understood by science, but the preliminary evidence suggests it protects against radiation and may help facilitate breathing as well.