Tea’s Health Benefits
So one of the most common questions I get is about the health benefits of tea, and I’m usually reluctant to touch the subject.
I know study after study is published that gets a lot of buzz in the news and it is an angle that attracts new drinkers to tea, but I’m usually pretty reluctant to expound on the subject for two main reasons.
My Personal Reluctance on the Subject
I think what is most fascinating and exciting about tea is the breadth of amazing natural flavors, the complete sensory experience, how it has shaped history and politics is so many ways, how tea is intertwined in so many cultures, how it has touched so many people in so many ways, and more and more…so that the health aspect is like the 16th most interesting thing about tea in my opinion.
It tends to give people unrealistic expectations of “what tea can do for them” health wise. I mean lets be real, tea is an amazing, enchanting, multifaceted beverage enjoyed all over the world but it is a BEVERAGE not medicine. Some unscrupulous promoters tend to overstate the health benefits of tea and then consumers get misguided start looking at tea as medicine.
Interestingly teas’ origins in China were as a medicinal elixir, but in Traditional Chinese Medicine (TCM) all food and drink are viewed as medicine when eaten or drunken strategically under the guidance of a TCM practioner. But let me repeat, while tea is a wonderful healthy beverage great for overall wellness, it is not medicine.
Either way, there is a huge interest in the health and wellness benefits of tea in general, so I wanted to take a chance to present a reliable overview, introduce the fundamentals of the relationship between tea and health, and offer links of published medical research for further reading if so inclined.
Not Just One Type of Tea Offers Health Benefits
To begin with, when people talk about tea and health they are usually talking about antioxidants found in tea. And before we get into the specifics of that, I want to remind everyone that all true tea is from the same plant (albeit often different cultivars of the same plant) cameilia sinesis, so whatever type of tea you like, the chemical and structural composition of the tea leaf isn’t that radically different.
Differing tea processing methods changes some of the nutritional profile and health effects of tea, but no matter the process, all tea leaves are dense with flavonoids (we’ll talk more about those in a second).
Related to that point, I really like one of the takeaways from a Washington Post article on the topic:
“Stick with the tea you enjoy most, whether white, green, oolong or black. All impart health benefits, and the studies are not detailed or numerous enough to choose one over another.”
Polyphenols, Flavonoids, Catechins and more!
Ok, lets get back to the specifics on the science of antioxidants in tea (get ready to nerd out! Warning: nerding out is so one of my favorite hobbies). When we look at tea and antioxidants, we are usually talking about flavonoid polyphenols, a category of antioxidants.
Polyphenols are a group of antioxidants that are the primary health-giving components of the tea plant. Flavonoids are a family of polyphenols found in tea and also found fruits, vegetables, and whole grains. According to Jeffrey Blumber, Professor of Nutrition Science and Policy at Tufts University, about one-third of the weight of a tea leaf is flavonoids!
He says: “A serving of tea is like adding a serving of fruits or vegetables to your diet.”
The flavonoids particularly present in tea are: catechin, theaflavins, and thearubigin. And the celebrity tea flavonoid that hogs up all the attention on the red carpet in studies and in the press is EGCG–a type of catechin particularly found in green tea.
Oxidation’s Effect on Flavonoids
Wait, I thought you just said earlier that no one tea is particularly more healthy than another–but you just mentioned EGCG in green tea is the celebrity, so are you saying green tea is the most healthy? Glad, you’re paying attention!
So the thing is, the reason why EGCG/green tea gets the most press is because EGCG is much more easily identified and studied than the flavonoid polyphenols in black tea.
Black tea’s reigning flavonoid polyphenols are theaflavins and thearubigin which have different health contributing properties than EGCG. As discussed here, the main chemical process that distinguishes different categories (white, green, yellow, oolong, black, and pu’er) of tea is level of oxidation.
As leaves oxidize and turn from green to black, the polyphenols also undergo a similar transformation making them different and harder to isolate.
Flavonoids multiply during the oxidation process, particularly theaflavins and thearubigin. Whereas oxidation reduces catechin levels (and remember EGCG is a type of catechin). So in less-oxidized teas (like white tea and green tea) you find more catechins like EGCG and in more oxidized teas (like black tea) you find more theaflavins and thearubigin. And for partially oxidized teas like oolong you find a little bit of both.
Why We Care About Anti-Oxidants
Research has shown that antioxidants act on free radicals in your cells. Some free radicals have a microscopic yet harmful affect on your cells and body and have been linked to chronic diseases and aging.
There have been studies that show that drinking lots of tea (all studies have subjects drinking at least 3 cups a day) has been linked to improved immune systems, lowering cholesterol, strengthening bones and fighting tooth decay among many other potential benefits.
And one of my favorite studies that sets my purist tea drinking heart aflutter is one that claims adding milk to your tea negates any health benefits you get from drinking tea. Compared with water, black tea “significantly improved” arterial function, researchers found, “whereas addition of milk completely blunted the effects of tea.” European Heart Journal, January 2007
To take it even further. You can go crazy searching this database of medical journals. Just type in tea and go wild.