Inventory the cupboards of all the households in the U.S and four out of five will have tea, according to the Tea Association of the U.S.A., with more than half of Americans (roughly 159 million in total) drinking this beverage on any given day.
While tea consumption has been associated with better heart health, a reduced risk of certain cancers, and a myriad of other health benefits, new research suggests some of the substances in tea may also improve immunity through their impact on the intestinal flora.
Tea polyphenols, the gut and immunity
Our digestive tract is home to around 100 trillion bacteria. Many of these bacteria live in the intestines, where they help break down the foods we eat, along with aiding in the absorption of the vitamins and minerals these items contain. Some of these bacteria promote good health, whereas others can be more damaging or harmful.
A 2021 article published in the journal Food Reviews International reports that tea polyphenols can influence intestinal flora by improving beneficial flora composition while, at the same time, reducing the growth of bacteria that have the potential to do more harm than good. The result is a healthier gut that is better able to regulate mood and sleep — two factors with major impacts on immunity.
Polyphenols are active compounds found in many plant-based foods, including tea. The polyphenols present in the tea depend on its type. Research published in Nutrients in 2019 explains that green tea is high in catechins, for example, while black tea tends to have more theaflavins and thearubigins.
The basis of the 2021 article is that negative emotions and sleep issues can hinder immune system function. Since both mood and sleep are regulated, at least in part, by the intestinal flora, finding ways to improve the health of this flora can positively impact immunity.
The authors of the study suggest tea polyphenols provide this effect, also creating a positive cycle, since intestinal flora improves polyphenol bioavailability by enhancing metabolism and absorption. So, drinking tea improves immune function through a healthier gut, which then boosts the ability to absorb and use polyphenols, creating a cycle of greater health.
Ways to consume more tea
The most obvious way to increase tea consumption is by drinking it daily. This beverage can be consumed hot or cold and is available in the form of tea bags or loose leaves that can be brewed, as well as in powders that can quickly be turned into a glass of refreshing iced tea.
For patients who don’t particularly enjoy the taste of tea, experimenting with different types and flavors may help them discover one they like. They can also experiment with other factors that can affect the strength of the flavor, such as how long the tea is allowed to steep and how many leaves to steep if using loose-leaf tea.
Adding other ingredients can also make tea more palatable for some. Honey and lemon are two common additions, with each one further enhancing immune system function. Research points to “convincing evidence” of honey’s ability to help prevent coughs and improve wound healing, mainly through its antioxidant and antibacterial properties. Other studies indicate lemon’s antioxidant properties help protect against oxidative stress.
Caution patients about caffeine
Many teas contain caffeine, making it critical to monitor tea consumption, especially for patients with caffeine sensitivity. For those wanting to avoid or limit their caffeine intake, herbal teas are a good option. Reading the label is important to ensure the tea chosen is free of this ingredient.
Tea’s many health benefits make it an all-around positive choice, providing allowances are made for any caffeine contained. It can contribute to gut and heart health, reduce cancer risk and improve immunity, as well as simply offer a fresh, healthier alternative to sugar-loaded choices such as soda or juice drinks.