Most of us have reached for a mug of hot tea in the hopes of easing a sore throat or staving off the common cold.
The concept of tea as medicine is nothing new. “The Chinese have been using this method for centuries to reduce ailments and improve the immune system,” says Paulina Lee, RD, a Houston-based registered dietitian who uses Western medical practices and alternative and integrative therapies to help clients address the root causes of their health concerns.
Despite the widespread use of tea for immunity, there is little hard scientific evidence to prove that tea offers this type of perk. Read on to learn what we’ve discovered about how tea may — or may not — keep your immune system on point.
How Tea May Support Your Immune Health
The bulk of tea’s immune and overall health benefits are tied to a group of antioxidants known as polyphenols. “A significant amount of epidemiological data has shown that a diet rich in polyphenols is protective against chronic health conditions such as cardiovascular disease and type 2 diabetes,” says Megan Meyer, PhD, the Durham, North Carolina–based senior director of science communications for the International Food Information Council. Her past research examined the effects of nutritional antioxidants on the immune system’s response to influenza.
Dr. Meyer points to a review published September 2017 in Nutrition Bulletin, which found that teas are especially rich in polyphenols known as flavonols. These plant chemicals have been shown to help lower blood pressure and cholesterol.
As far as your immune system is concerned, antioxidants (like the flavonols in tea) can help protect your body against free radicals generated by pollution, cigarette smoke, and ultraviolet rays, according to Harvard Health. Free radicals can have harmful effects on the body, including a weakened immune system, per a past review.
There are many tea varieties that may support your immune health. Popular options like green, black, white, and oolong all come from the same evergreen plant, Camellia sinensis, according to the Harvard T.H. Chan School of Public Health. “What makes them distinct is how they are prepared,” Meyer says. Differences in processing, geographical location, and plant varieties account for the unique flavors and nutritional compositions of tea, and may mean some teas offer more immune benefits than others.
Herbal teas may also support your immune health. “Most herbal teas are known to have health-supporting qualities,” Lee says.
Herbal teas are not made from the Camellia plant but from dried herbs, spices, roots, seeds, fruit, or leaves of other plants, according to the Harvard T.H. Chan School of Public Health. Depending on the nutritional makeup of a given plant, some herbal teas may be better for your immune health than others.
More Research on Tea and Immune Health Is Needed
While the research on tea and immune health sounds promising, the studies thus far either don’t use humans, or the population sizes are relatively small. Many studies also use tea in capsule or tablet forms, which usually pack a far greater dose of plant compounds than you’d find in a tea bag. Given these limitations, it’s tough to know whether and how a cup of tea will benefit a typical person’s immune health. More large studies in humans using brewed tea are needed.
That said, health experts generally agree: Brewed tea sans sweetener is a healthy beverage choice. “I personally believe that teas are a great way to add functional foods and herbs to your diet on a daily basis,” Lee says. So drink up! And if immune health is your top concern, you might want to start with this list of the top teas for a healthy immune system, in order from strongest evidence to weakest.
