Rooibos tea is gaining popularity as a delicious and healthy beverage.
Consumed in South 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 this tea for its potential health benefits.
Many have suggested that its antioxidants can help to protect against cancer, heart disease and stroke.
But how many of these health claims are true? This article explains what rooibos tea is, its top 5 health benefits, as well as any 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).
Here's what the leaves look like: 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 is also available, which is not fermented. It tends to be more expensive and has a more grassy flavor than the traditional version of the tea (2).
An added bonus of the green variety is that it contains higher levels of antioxidants compared to the traditional red type (3).
Rooibos tea is usually consumed in a similar way to black tea. Some people like to add milk and sugar to taste. More recently, iced tea, espressos, lattes and cappuccinos made from the tea have been introduced in some countries.
Contrary to some claims, rooibos tea is not a good source of vitamins or minerals, with the exception of copper and fluoride (4).
However, it is full of powerful antioxidants, which may have some health benefits.
Bottom Line: Rooibos tea is a traditional beverage made using the leaves of a shrub from South Africa. It is consumed in a similar way to black tea and contains lots of 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).
Another bonus is that it has low tannin levels compared to regular black or green tea.
Tannins are a natural compound found in green and black tea. They often get a bad reputation because they interfere with the absorption of certain nutrients, like iron.
Finally, unlike black tea and to a lesser extent green tea, red rooibos contains no oxalic acid.
Consuming high amounts of oxalic acid can increase your risk of kidney stones. This means the tea is a good option for anyone with kidney problems.
Bottom Line: Compared to regular black tea or green tea, rooibos is caffeine-free and lower in tannins and oxalic acid.
They may help protect cells from damage by free radicals.
Over the long term, their effects may help reduce the risk of disease, including heart disease and cancer (9).
There is some evidence that drinking rooibos tea can increase antioxidant levels in the body.
However, any increase documented has been small and doesn't last for too long.
One study of 15 people found that antioxidant levels in the blood increased by 2.9% when participants drank the red variety of rooibos and 6.6% when they drank the green variety.
This increase lasted for five hours after the participants drank 17 oz (500 ml) of tea made with 750 mg of rooibos tea leaves (10).
However, another study of 12 healthy men found that drinking rooibos tea had no effect on blood antioxidant levels compared to regular tea (11).
Bottom Line: Rooibos tea is full of health-promoting antioxidants. However, these antioxidants may be unstable or inefficiently absorbed into the body.
Antioxidants found in the tea have been 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) (15).
ACE indirectly increases blood pressure by causing blood vessels to contract.
A study involving 17 people found that drinking rooibos tea resulted in the inhibition of ACE activity 30–60 minutes after participants drank the tea (15).
However, this did not translate to any changes in blood pressure.
There is more promising evidence that the tea can improve cholesterol levels.
One study examined the effects of rooibos on 40 overweight men and women at higher risk of heart disease.
The researchers found that drinking six cups of rooibos tea daily for six weeks resulted in a decrease in low-density lipoprotein (LDL) cholesterol, also known as the "bad" cholesterol.
It was also associated with a small increase in high-density lipoprotein (HDL) cholesterol. That's the "good" cholesterol (16).
However, the same effect was not seen in healthy people.
Healthy cholesterol levels mean added protection against various heart conditions, including heart attacks and strokes.
Bottom Line: Rooibos tea may benefit heart health by positively affecting blood pressure. It may also lower "bad" cholesterol and raise "good" cholesterol in people who are at risk of heart disease.
However, the amount of quercetin in a cup of the tea is only a small percentage of the total antioxidants present.
Therefore, it's not clear whether there are enough of these two antioxidants, and if they are absorbed efficiently enough in the body to have beneficial effects.
Studies in humans need to be carried out to provide stronger evidence that drinking rooibos tea can actually prevent cancer growth.
Bottom Line: Certain antioxidants in rooibos tea have been shown to kill cancer cells and prevent tumor growth. However, no human studies exist.
Rooibos tea is one of the few known natural sources of an antioxidant called aspalathin. Studies in animals suggest that aspalathin may have an anti-diabetic effect (19).
One study in mice with type 2 diabetes found that aspalathin helps to balance blood sugar levels and reduces insulin resistance. This is promising news for people with type 2 diabetes or those at risk of developing it (20).
However, more studies in humans are needed to confirm this benefit.
Bottom Line: Animal studies suggest that specific antioxidants in rooibos tea can help balance blood sugar and improve insulin resistance. However, studies in humans are needed.
The health claims related to rooibos tea range widely. However there is generally a lack of evidence to support many of these:
- Bone health: Evidence linking rooibos consumption to improved bone health is weak. In addition, studies focusing on rooibos tea specifically 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 some anecdotal reports of improvements, there is no strong evidence that it can help sleep problems, allergies, headaches or colic.
Bottom Line: There is currently no strong evidence that rooibos tea improves bone health, digestion, sleep, allergies, headaches or colic.
In general, this tea 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 have shown estrogenic activity, meaning they can stimulate production of the female sex hormone, estrogen (23).
Therefore, 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 it would have an effect.
Bottom Line: Rooibos is generally very 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.