Rooibos tea is gaining popularity as a delicious and healthy beverage.

Consumed in southern Africa for centuries, it has become a beloved drink around the world.

It's a flavorful, caffeine-free alternative to black and green tea.

What's more, advocates praise rooibos for its potential health benefits, claiming that its antioxidants can protect against cancer, heart disease and stroke.

However, you may wonder if these benefits are supported by evidence.

This article explores rooibos tea’s health benefits and potential side effects.

Rooibos tea is also known as red tea or red bush tea.

It is made using leaves from a shrub called Aspalathus linearis, usually grown on the western coast of South Africa (1).

Rooibos is a herbal tea and is not related to green or black tea.

Traditional rooibos is created by fermenting the leaves, which turns them a red-brown color.

Green rooibos, which is not fermented, is also available. It tends to be more expensive and grassier in flavor than the traditional version of the tea, while also boasting more antioxidants (2, 3).

Rooibos tea is usually consumed like black tea. Some people add milk and sugar — and rooibos iced tea, espressos, lattes and cappuccinos have also taken off.

Contrary to some claims, rooibos tea is not a good source of vitamins or minerals — aside from copper and fluoride (4).

However, it is full of powerful antioxidants, which may offer health benefits.

Summary Rooibos tea is a traditional beverage made from the leaves of a South African shrub. It is consumed in a similar way to black tea and contains many antioxidants.

Caffeine is a natural stimulant found in both black tea and green tea.

Consuming moderate amounts of caffeine is generally safe.

It may even have some benefits for exercise performance, concentration and mood (5).

However, excessive consumption has been linked to heart palpitations, increased anxiety, sleep problems and headaches (5).

Therefore, some people choose to avoid or limit caffeine intake.

Because rooibos tea is naturally caffeine-free, it's an excellent alternative to black or green tea (6).

Rooibos also has lower tannin levels than regular black or green tea.

Tannins, natural compounds present in green and black tea, interfere with the absorption of certain nutrients, such as iron.

Finally, unlike black tea — and green tea, to a lesser extent — red rooibos contains no oxalic acid.

Consuming high amounts of oxalic acid can increase your risk of kidney stones, making rooibos a good option for anyone with kidney problems.

Summary Compared to regular black tea or green tea, rooibos is lower in tannins and free from caffeine and oxalic acid.

Rooibos is associated with health benefits due to its high levels of health-promoting antioxidants, which include aspalathin and quercetin (7, 8).

Antioxidants may help protect cells from damage by free radicals.

Over the long term, their effects may reduce your risk of illnesses, such as heart disease and cancer (9).

There is some evidence that rooibos tea can increase antioxidant levels in your body.

However, any increase documented has been small and doesn't last long.

In one 15-person study, blood levels of antioxidants increased by 2.9% when participants drank red rooibos and 6.6% when they drank the green variety.

This uptick lasted for five hours after the participants drank 17 ounces (500 ml) of tea made with 750 mg of rooibos leaves (10).

Another study in 12 healthy men determined that rooibos tea had no significant effects on blood antioxidant levels compared to a placebo (11).

This is possibly because the antioxidants in rooibos are short-lived or inefficiently absorbed by your body (11, 12).

Summary Rooibos tea is full of health-promoting antioxidants. However, these antioxidants may be unstable or inefficiently absorbed by your body.

Antioxidants in rooibos are linked to a healthier heart (13).

This may happen in different ways (14).

First, drinking rooibos tea may have beneficial effects on blood pressure by inhibiting angiotensin-converting enzyme (ACE) (14).

ACE indirectly increases blood pressure by causing your blood vessels to contract.

In a study in 17 people, drinking rooibos tea inhibited ACE activity 30–60 minutes after ingestion (15).

However, this did not translate to any changes in blood pressure.

There is more promising evidence that the tea can improve cholesterol levels.

In a study in 40 overweight adults at high risk of heart disease, six cups of rooibos tea daily for six weeks decreased “bad” LDL cholesterol while boosting “good” HDL cholesterol (16).

However, the same effect was not seen in healthy people.

Healthy cholesterol levels give added protection against various heart conditions, including heart attacks and strokes.

Summary Rooibos tea may benefit heart health by positively affecting blood pressure. It may also lower "bad" LDL cholesterol and raise "good" HDL cholesterol in those at risk of heart disease.

Test-tube studies note that the antioxidants quercetin and luteolin, which are present in rooibos tea, can kill cancer cells and prevent tumor growth (17, 18).

However, the amount of quercetin and luteolin in a cup of the tea is very small. Many fruits and vegetables are much better sources.

Therefore, it’s unclear whether rooibos packs enough of these two antioxidants, and whether they’re absorbed efficiently enough by your body to provide benefits.

Keep in mind that human studies are needed on rooibos and cancer.

Summary Certain antioxidants in rooibos tea have been shown to kill cancer cells and prevent tumor growth in test tubes. However, no human studies have confirmed these effects.

Rooibos tea is the only known natural source of the antioxidant aspalathin, which animal studies suggest may have anti-diabetic effects (19).

One study in mice with type 2 diabetes found that aspalathin balanced blood sugar levels and reduced insulin resistance, which could prove promising for people who have or are at risk of type 2 diabetes (20).

However, human studies are needed.

Summary Animal studies suggest that specific antioxidants in rooibos tea can help balance blood sugar and improve insulin resistance. However, human research is necessary.

The health claims surrounding rooibos tea vary widely. However, there is a lack of evidence to support many them. Unverified benefits include:

  • Bone health: Evidence linking rooibos consumption to improved bone health is weak, and specific studies are scarce (21).
  • Improved digestion: The tea is often promoted as a way to reduce digestive problems. However, evidence for this is weak.
  • Others: Despite anecdotal reports, there is no strong evidence that rooibos can aid sleep problems, allergies, headaches or colic.

Of course, the lack of evidence does not necessarily mean that these claims are false — just that they haven’t been studied fully.

Summary There is currently no strong evidence that rooibos tea improves bone health, digestion, sleep, allergies, headaches or colic.

In general, rooibos is very safe.

Although negative side effects are extremely rare, some have been reported.

One case study found that drinking large amounts of rooibos tea daily was linked to an increase in liver enzymes, which can often indicate a liver problem. However, this was only one complex case (22).

Certain compounds in the tea can stimulate the production of the female sex hormone, estrogen (23).

Some sources suggest that people with hormone-sensitive conditions, such as breast cancer, may want to avoid this type of tea.

However, this effect is very mild and it is likely that you would need to consume very large amounts before you would see an effect.

Summary Rooibos is safe to drink, and negative side effects are extremely rare.

Rooibos tea is a healthy and delicious beverage.

It is caffeine-free, low in tannins and rich in antioxidants — which may offer a variety of health benefits.

However, health claims relating to the tea are often anecdotal and not based on strong evidence.

It is still not clear whether the benefits of rooibos tea seen in test-tube and animal studies translate into real-world health benefits for humans.

If you'd like to give rooibos tea a try, you can find a wide section on Amazon.