Certain varieties of tea contain helpful plant compounds that may play a role in boosting your immunity. Although more research is needed, here are some teas that health experts say are worth steeping. Most of us have had a cup of hot tea in the hopes of easing a sore throat or warding off a cold.
The concept of tea as medicine is not new. The Chinese have used this method for centuries to alleviate ailments and improve the immune system. Despite the widespread use of tea for boosting immunity, there is little hard scientific evidence for this type of benefit. Read on to find out what we found out about how tea can — or can’t — keep your immune system in shape.
How Tea Can Support Your Immune Health
Most of tea’s immune system and overall health benefits are linked to a group of antioxidants called polyphenols. Numerous epidemiological data show that a diet rich in polyphenols protects against chronic diseases such as cardiovascular disease and type 2 diabetes.
In a study published in September 2017 in Nutrition Bulletin, teas were shown to be particularly high in polyphenols known as flavonols. These plant chemicals have been shown to help lower blood pressure and cholesterol. When it comes to your immune system, antioxidants (like the flavonols in tea) can help protect your body against free radicals generated by pollution, cigarette smoke, and ultraviolet rays. Free radicals can have adverse effects on the body, including weakening the immune system, according to a previous study.
There are many varieties of tea that can support your immune health. Popular options like green tea, black tea, white tea, and oolong tea all come from the same evergreen plant, Camellia sinensis. What sets them apart is how they are prepared. Differences in processing, geographic location, and plant varieties explain tea’s unique flavors and nutritional compositions, and may mean that some teas offer more immune benefits than others.
Herbal teas can also support your immune health. Most herbal teas are known for their health benefits. Herbal teas are not made from the Camellia plant but from herbs, spices, roots, seeds, fruits or dried leaves of other plants. Depending on the nutritional makeup of a given herb, some herbal teas may be better than others for your immune health.
While the research on tea and immune health looks promising, studies so far have not involved humans or the population sizes are relatively small. Many studies also use tea in capsule or tablet form, which typically contain a much higher dose of plant compounds than is found in a tea bag. Given these limitations, it’s hard to know if and how a cup of tea benefits the immune health of a typical person. Further large studies on humans using brewed tea are needed.
That said, health experts generally agree: Brewed tea without sweeteners is a healthy beverage choice. And if immune health is your main concern, you can start by checking out this list of the best teas for a healthy immune system, in order of strongest to weakest evidence.
1 Green tea
Sweet and sour green tea is a rich source of catechins. Catechins are polyphenols that have an overall positive effect on well-being and are notable antioxidants. Epigallocatechin gallate (EGCG) is one of the most abundant and well-known catechins in green tea. It also has benefits for your immune system. For example, a previous study showed that treating mice with EGCG increased the number of regulatory T cells in their spleen and lymph nodes. Regulatory T cells modulate the immune response, which helps your system stay balanced and prevents it from attacking healthy cells.
Research suggests that EGCG may also affect immune function in humans. In a study published April 2021 in Biochemical and Biophysical Research Communications, researchers treated T cells taken from 20 healthy adult men with EGCG that they had isolated from green tea dissolved in water. They found that EGCG prevented T cells from creating pro-inflammatory proteins called cytokines, suggesting that the plant compounds in green tea may help regulate the immune system.
While these results provide clues to the link between green tea and immunity, more research in humans, people with compromised immune systems, and larger populations is needed to find out for sure.
2 Turmeric tea
Turns out turmeric, the orange-yellow spice that gives curry its bold color, can also be a boon for your immune system when enjoyed in tea. Research shows that turmeric can reduce inflammation and it contains high levels of antioxidants, both of which support overall immune function.
The main active compound in turmeric is curcumin. According to an October 2017 review in Foods, curcumin effectively scavenges different types of free radicals, controls enzymes that neutralize free radicals, and helps prevent the creation of free radicals. Given the role that free radical damage can play in many diseases, the antioxidants in turmeric can make this spice a handy addition to your immune health regimen.
Researchers have also found that curcumin may play an important role in immune response. For example, a past study using cultured mouse spleen cells found that curcumin could regulate T cells and B cells, two lymphocytes that recognize and respond to foreign substances in your body. In the aforementioned study, curcumin helped regulate the immune response to prevent immune cells from attacking healthy tissue. The researchers concluded that curcumin could be a promising therapy for keeping the immune system in check. However, there is insufficient research on humans and on turmeric tea in particular, which means scientists don’t yet know if you’ll be able to get these benefits from sipping it in tea form.
3 Black tea
This bold, dark variety of tea owes its dark color to a group of polyphenols called theaflavins. Research supports the antioxidant potential of theaflavins, even when compared to ECGC. Yet the antioxidants in black tea may have unique effects on the immune system. For example, an earlier clinical trial found that healthy people (defined in this case as not suffering from any serious illness and having normal or mildly elevated systolic blood pressure) who drank three cups of black tea a day for six months showed increased immune activity. The researchers looked at three markers that indicate the immune system has kicked into high gear: neopterin, kynurenine, and tryptophan. While black tea did not have a significant effect on neopterin or tryptophan levels, it did increase kynurenine, suggesting that black tea polyphenols help activate the immune response in healthy people. . The fact that human subjects drank black tea in this study is an advantage. But the sample size was small – 45 people drank tea and 49 were in the control group. To better understand the effect of tea drinking on specific health conditions and on the immune system, further studies on different patients and, ideally, on larger sample sizes are needed.
4 White tea
Thanks to minimal processing, white tea is one of the lightest and most delicately flavored varieties on the market. Like its green cousin, white tea has high levels of catechins. Indeed, previous research suggests that white tea has similar antioxidant benefits to green tea, although green tea’s antioxidant potential is even greater, notes Lee. There is no solid human research on the white tea and immunity, which is why this variety is low on the list. Still, the minimal evidence we have so far suggests that it may be worth closer examination in future literature. For example, a test-tube study found that white tea extract helped protect nerve cells in rats from damage caused by hydrogen peroxide, a free radical. And another test-tube study found that white tea extract helped control inflammation in human skin cells caused by free radicals.
Additionally, white tea may have antimicrobial effects. For example, researchers tested the antimicrobial effects of white tea leaves against the bacteria Streptococcus mutans and Streptococcus sobrinus, two microorganisms that contribute to tooth decay. After a 72-hour incubation period, researchers found that white tea extracts exhibited significant antibacterial effects against Streptococcus mutans, suggesting that white tea extract may help protect against tooth decay. The results were published in August 2019 in Materials Today: Proceedings.
While test-tube studies like these can produce some interesting results, they don’t provide the full picture. Further studies of humans drinking brewed tea are needed to understand how white tea affects the immune system. “An herb or supplement that passes through our digestive system must be absorbed into the bloodstream, undergo processing in the liver, and remain effective once diluted in the body,” Lee explains. Test-tube studies should therefore be taken with a grain of salt.
5 Ginger Tea
A close relative of turmeric, ginger may also provide immune health benefits when consumed in a cup of tea. Gingerol is the main active compound responsible for the spicy, peppery flavor of ginger and its medicinal properties. According to a previous study, gingerol not only has antioxidant and anti-inflammatory effects, but it can also treat infections. In addition to gingerol, ginger contains other antiviral compounds that are effective in fighting the common cold, notes an earlier research paper. These compounds are associated with reduced pain, fever, and coughing fits associated with colds. That said, few studies have looked at the effects of ginger on the immune system and the effects of ginger tea in particular. More research is needed to conclude whether ginger tea may play a role in immune health.