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Healthy You

Tea 101: What's in Your Cup?

Tuesday, January 14, 2020 11:00 AM

Tea comes in many varieties, and each one comes with its own uniqueness. Lori Bumbaco, a NorthShore dietitian, lays out the facts and differences between the many varieties you can put in your morning cup.

Multiple Teas

Did You Know?

  • Tea is one of the world’s most ancient and popular beverages, following water. 
  • The earliest record of tea described it as a medicinal beverage in China in the third century AD. 
  • Cultures have historically used tea for health benefits, but additional research is needed to confirm the promising value of daily consumption of 2-3 cups of tea. 
  • The flavor of tea varies according to where the tea leaves are harvested, and how they are grown and processed. 
  • Black tea is the most popular worldwide, followed by green, oolong, and white tea. Tea comes from the leaves of the Camellia sinensis plant and is made by pouring hot water over cured leaves. 
  • Herbal teas are not made from the Camellia plant but instead from dried herbs, spices, flowers, fruit, seeds, roots, or leaves of other plants; they naturally are caffeine-free, unlike traditional teas.

What is in Your Cup?

Interestingly, tea does not contain many nutrients. It is however chockfull of healthful compounds called polyphenols. Polyphenols are chemical compounds, and tea has high concentrations of them from flavonols, theaflavins and catechins. The amount of these compounds depends on the type of tea used and how you prepare it. 

Polyphenols, or flavonoids, are likely a key component to what makes tea a healthful drink. These chemical compounds act as antioxidants, which control the damaging effects of free radicals in the body. Some research has found that polyphenols in tea are associated with reduced risk of premature death, heart disease, stroke, and type 2 diabetes. One of the most studied of these compounds is epigallocatechin-3 gallate, EGCG, which shows promise in reducing cancer risk.

Teas to Try

At least 5,000 years old, all true teas originate from the Camellia sinensis plant, with the type of tea determined by the amount of time the leaves are exposed to air, or oxidized, resulting in five distinct types of tea.

The lightest and most delicate is white, an unoxidized tea made from the tiny unopened plant buds with one or two young, open leaves sometimes added. EGCG content is higher than green tea, though not necessarily higher in total antioxidants. 

Green tea is produced from the green leaves before it is fermented or oxidized and imparts a delicate flavor. Green tea is rich in epigallocatechin-3 gallate, which has been shown to be a stronger antioxidant than vitamins C and E. It also contains L-theanine which is a unique amino acid, which is thought to exert calming effects.

Matcha, the tea used in a Japanese tea ceremony, is a very fine green powder made from the green leaves of tea bushes grown in the shade. It's the only tea where the leaves are consumed as part of the drink rather than being infused in hot water. Therefore, the antioxidant content is higher than other teas, and it's a particularly rich source of L-theanine, an amino acid unique to tea.

Oolong tea is made from partially oxidized tea leaves and has a flavor halfway between green and black tea. The polyphenols found in oolong tea are called theasinensins. 

Black tea is produced from totally oxidized leaves. It has a darker color and stronger flavor from the polyphenols called thearubigins. Black tea has the highest concentration of thearubigins and theaflavins compared to other teas, 

Finally, dark tea, or pu-erh, is fully oxidized as well as fermented by anaerobic bacteria, imparting a woodsy, earthy flavor. 

What About Kombucha?

Kombucha is fermented from tea (usually black, though sometimes green) and sugar, resulting in a slightly fizzy drink that contains probiotics. Probiotics are live bacteria and yeasts or “healthy little microbes” that have been associated with digestive benefits. Polyphenols are also present in kombucha depending on the type of tea used. 

Those with compromised immune systems are advised to avoid kombucha. Tainted batches can become contaminated with undesirable fungi and an overproduction of yeast. It is advised to buy commercial products, instead of homemade versions that may lack proper sanitary guidelines. 

Ready-to-Drink Tea

Although convenient, bottled teas often contain added sugar and typically are lower in polyphenols and total antioxidants. Make sure to check the label to buy unsweetened versions. 

Chai tea offers the added flavor and phytochemicals of ginger, cloves, and other spices. It usually contains added milk and substantial amounts of added sugars. It is best to make your own, or experiment with cinnamon to sweeten your brewed tea.