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Tips for reading news about tea studies
As Dr. Oz is being thoroughly (and rightfully) shredded by the Senate Commerce, Science, and Transportation Committee for pimping weight-loss scams, we shouldn’t lose sight of the fact that (a) there are a lot of valid health benefits to tea, and (b) virtually every news story about tea and health manages to misrepresent or misinterpret the scientific study they’re describing.
As you read articles about tea and health, it’s important to keep in mind that the person writing the article is usually not the person (or people) who actually performed the study it references, and that the reporter/blogger may have read only the summary, not the whole study. Also, in larger news operations, the person writing the headline isn’t the same person who wrote the article, and if they’re operating on a deadline, the headline may not accurately sum up the story.
Tip 1: Beware of extreme claims
There’s an article on Authority Nutrition entitled,”How Green Tea Can Help You Lose Weight Naturally.” It’s worth reading. There are good explanations of the benefits of tea, and it cites dozens of actual scientific studies. But any article that begins with a statement like “green tea is the healthiest beverage on the planet” should set off alarm bells. No, there’s never been a study that tested every single beverage on the planet (there’s never been a study of every style of tea on the planet, for goodness’ sake). No, we don’t have a generally-accepted definition of “healthiest beverage.” An opening sentence like that one tells you you’re about to read something sensationalistic, and you should view everything they say with skepticism.
Any article that begins with a statement like “green tea is the healthiest beverage on the planet” should set off alarm bells.
Tip 2: They only studied what they studied
There’s an article on Byron J. Richards Wellness Resources entitled, “The Effects of Green Tea on Weight Management.” The author is a Board Certified Clinical Nutritionist, the studies cited all appear to be properly-conducted randomized controlled trials, and the conclusions all appear to be valid. So what’s the problem? Reading this may make you want to rush to your tea cabinet and throw away all of those white teas, oolong teas, yellow teas, and pu-erh teas. You need to replace those all with green tea, right. Wrong!
The studies looked at green tea. Specifically, they measured catechins and caffeine in green tea. They never compared green tea with white tea — or any other kind of tea. White tea may be even better for weight loss. So might oolong, pu-erh, or yellow. If green tea is measured against anything else in a study, it’s almost always black tea. What’s the difference between green and black tea? Black tea is oxidized, and that process converts a lot of the antioxidants into other compounds (catchins are a type of antioxidant). But white and yellow tea isn’t oxidized, and oolong is only partially oxidized. Shu pu-erh is oxidized and fermented, and sheng pu-erh is fermented without being oxidized first. Don’t draw conclusions about your oolong from a study that never even looked at oolong!
Tip 3: There’s more to tea than antioxidants
I think it’s pretty universally agreed that antioxidants are a good thing, but they aren’t the only source of health benefits in tea. When I got in a tiff with Fox News’ Chris Kilham about misrepresenting studies, it related to a study that showed coffee had some great health benefits. Reading the study showed that it looked at one thing: caffeine. All of the health benefits it listed for coffee would apply just as much to tea, guayusa, yerba maté, or Mountain Dew. If you like black tea, don’t let yourself get talked out of drinking it just because it doesn’t have the same antioxidant content as green tea.
Tip 4: All green tea is not created equal
It’s wonderful to see an article like the one titled, “Green Tea,” on the University of Maryland Medical Center page. It has tons of information, cites numerous studies, and explains potential drug interactions and side effects. But, like all of the other articles, it just references “green tea.” Did they test Japanese steamed green tea like sencha? Pan-fired Chinese green tea like longjing? Or was it roasted (hōjicha), powdered (matcha), shade-grown (gyokuro), scented (jasmine), or rolled (gunpowder)? The Kevin Gascoyne study I referenced in my 3-part series on caffeine found tea caffeine content ranging from 12mg to 126mg per cup. Yes, the most caffeinated tea had ten times as much caffeine as the least. He found a similar range of antioxidant contents. If you want to replicate the results of the study, you have to know what kind of tea they used.
Tip 5: Pay attention to who funded the study
If they had done a study that found that green tea gives people smelly feet, how much publicity do you think that would have gotten?
You can’t automatically discount a study because the funding group had something to gain from it. Tea companies are the ones most likely to fund tea studies, after all. But take a look at “Green Tea Promotes Weight Loss, New Research Finds,” an article on Medical News Today (well, actually, it’s a press release, but they don’t make that obvious until the end). It’s very clear in reading the article that Lipton did the research, and that Lipton is very excited about having done the research. It’s a big company, and their PR department did a good job of really spreading the news about that study.
If they had done a study that found that green tea gives people smelly feet, how much publicity do you think that would have gotten? I always tend to pay a little more attention to research coming from neutral parties, or research that’s been duplicated by neutral parties.
Tip 6: Check to see if the methodology was realistic
WebMD has an article entitled, “Green Tea Fights Fat,” which does appear to actually compare weight loss effects of green tea with oolong tea. But read this sentence from the article carefully: “For three months, the first group drank a bottle of oolong tea fortified with green tea extract containing 690 milligrams of catechins, and the other group drank a bottle of oolong tea with 22 milligrams of catechins.”
First, they aren’t comparing green tea with oolong. Both groups drank oolong tea. In one group, they added green tea extract, and in the other, they didn’t. So this study actually compares drinking oolong with drinking oolong plus green.
Second, the average cup of green tea has 50-100mg of catechins. That means the “extract” they fortified the bottle of oolong with made it equivalent to 7-14 cups of green tea. That’s a lot of tea!
If you have specific reasons for controlling your intake of caffeine, L-theanine, catechins, and other components, then there’s plenty of research to plunge into. Focus on people who actually study tea rather than folks like Dr. Oz or Oprah. Look at the paper and see what they actually studied. If it doesn’t apply to you, move on to the next one. If it does, take it at face value without trying to overgeneralize.
But if you’re just looking for a healthy drink that tastes good, stop worrying and buy more of what you like the most. You’re likely to drink a lot more of a beverage you love than one you don’t. If you like to experiment, all the better! If you drink a wide variety of tea, you’ll get a wide variety of nutritional benefits, and you can enjoy yourself as you do it.
Caffeine Math: How much caffeine is in a tea blend?
For some reason, it seems like I write a lot about caffeine on this blog. My three-part series on the subject is the most popular thing I’ve ever posted. My recent post about theanine talked about caffeine as well. One thing I haven’t addressed in detail is what happens to caffeine content when you blend tea with something else.
The first thing we have to do is clear our minds of preconceptions. Remember that there’s no simple formula saying that one kind of tea has more caffeine than another (see my caffeine myths article for details). And resign yourself to the fact that there’s no way short of spending a couple of thousand dollars on lab tests to determine how much tea is in a commercial blend, for reasons I’ll explain in a moment.
Let’s start with an example. Assume you have a tea you enjoy. You use two teaspoons of tea leaf to make a cup, and we’ll say this tea gives you 20mg of caffeine. You decide to use this tea in a blend. What happens to the caffeine level?
Ingredient blends
If you blend with other bulk ingredients, the caffeine calculations are simple ratios. If you blend the tea 50/50 with peppermint, then instead of two teaspoons of tea (20mg of caffeine), you’re using one teaspoon of tea (10mg of caffeine) plus one tablespoon of mint (no caffeine). You’ve cut the amount of caffeine in half. If your blend is 1/3 ginger and 2/3 tea, it will have 2/3 as much caffeine as the straight tea.
If you’re blending tea with other tea, the ratios work the same way. Blend together two tea styles with equivalent caffeine levels and the result will have the same amount of caffeine as the original tea blends.
All of this is contingent upon your measuring techniques. It becomes more complicated if you blend by weight instead of volume. Put together a cup of green tea and a cup of peppermint, and two teaspoons of the blend will contain (about) one teaspoon of tea and one teaspoon of mint. If you put together an ounce of gunpowder green tea and an ounce of peppermint leaves, the result is very different. Gunpowder tea is very dense, and peppermint leaves are light and fluffy. Two teaspoons of that mixture might only have a half teaspoon of tea, which means a quarter of the caffeine.
Extracts and oils
In many commercial tea blends whole ingredients like chunks of berry, flakes of cinnamon, and bits of leaf are more for looks than flavor. Soak a strawberry in hot water for three minutes and you’ll see what I mean. The real flavoring in those blends comes from extracts and essential oils that are sprayed on the tea leaves. In that case, the caffeine content is pretty much unaffected. A teaspoon of flavored tea leaves has the same caffeine as a teaspoon of unflavored tea leaves.
A little tea blending secret: sometimes the chunks of fruit in the tea really are chunks of fruit, but they’re not what you think they are. Tea blenders can purchase small chunks of dried apple that are sprayed with (or even soaked in) flavorings or extracts. Your piña colada blend might just be apple bits flavored with coconut and pineapple extracts. There’s very little flavor in the dried apple, so all you’re getting is the flavoring that was added. Why use them at all? Because it’s easy to experiment with, it doesn’t require the tea company to invest in leaf-spraying equipment, and it adds some visual variety to the blend. The chunks can even be colored.
A couple of real-world examples
Let’s start with genmaicha. This is a classic Japanese blend of green tea and roasted rice. I started with a tablespoon of my favorite genmaicha:
The base tea in this blend is sencha, which is fairly easy to recognize from the color and needle shape of the leaves. I don’t know the exact caffeine content of the sencha, but I can do a bit of Googling and come up with an estimate. Let’s go with 30mg per cup. Now, we’ll separate the tea leaves from the rice:
The main thing I learned from this exercise is that I don’t have the patience to pick all of the rice out of a tablespoon of genmaicha! The separation I did showed that a tablespoon of this particular genmaicha contained about 1/3 tablespoon of rice and 2/3 tablespoon of sencha. Since rice has no caffeine, that means a cup of this genmaicha probably has about 20mg of caffeine in it.
I was going to try the same experiment with a Moroccan mint tea, but found that the one I have on hand has no peppermint leaves. It appears to contain only tea leaves and mint extract. That means it has the same caffeine level as the tea used to make it — in this case a gunpowder green tea.
Doing the math
I don’t think you actually have to do much math to estimate caffeine levels. It’s imprecise at best because tea leaves don’t come labeled with their caffeine content. But if you look at a tea blend and it appears to be about half tea leaves and half something else, it’ll have about half the caffeine of the tea alone. Some blends I’ve looked at lately appear to have very little tea leaf — those might as well be decaffeinated tea! Others, like the Moroccan mint I mentioned a moment ago, are almost entirely tea, so treat them just as you would unflavored tea.
Japan – Bancha to Matcha: Stop 4 on the World Tea Tasting Tour
We’re very excited to be working with resident artist Karin Solberg from the Red Lodge Clay Center, and we are featuring some of her matcha bowls in the store, and she came in to talk about them at this stop in the tour.
The teas we tasted were:
- Organic Sencha
- Gyokuro
- Organic Houjicha (roasted green tea)
- Organic Genmaicha (toasted rice tea)
- Organic Matcha
- Kukicha (“twig tea”)
- Bancha (“coarse sencha”)
- Sencha (“decocted tea”)
- Gyokuro (“jade dew”)
What’s the difference between Japanese and Chinese green tea?
Japanese sencha leaves
As I did last month and the month before, I took a look at some of the search terms that brought people to this blog and found a question that I didn’t really address. This time: “What’s the difference between Japanese and Chinese green tea?” The obvious smart-aleck answer is that one comes from Japan and the other comes from China, but it runs a bit deeper than that.
First off, it’s not the plants themselves. The first varietal discovered of the tea plant is Camellia sinensis var. sinensis: the Chinese tea plant. About 1400 years ago, during the Sui Dynasty, Buddhist monks introduced tea — and the tea plant — to Japan. This means that the same varietal of tea plant is growing in China and Japan.
Terroir, on the other hand, can definitely have an effect. The climate, soil, and other factors can definitely affect the taste of the tea. Also, the Japanese have been crossbreeding and developing their strains of tea plant for over a millennium.
The biggest factor in the taste, though, is a very simple one: the process.
The difference between black tea and green tea is oxidation. Black tea is fully (or near-fully) oxidized, while green tea is not oxidized at all. There is an enzyme in the tea leaf that starts the oxidation process as soon as the leaf has been broken or bruised. Making green tea requires a “kill green” step that destroys the enzyme and stops the tea from oxidizing. That step requires heating the tea leaves quickly to at least 140 degrees.
To make Japanese green teas, such as sencha, bancha, and gyokuro, the leaves are steamed. To make Chinese green teas, such as dragonwell or gunpowder tea, the leaves are pan-fired. Just this simple difference in processing gives Japanese teas a rich grassy flavor and Chinese greens more of a vegetal character.
Granted, I am oversimplifying, but this is the fundamental answer to the question.
A Tea Tasting and Class
This article first appeared in the May 2010 issue of the Local Rag newspaper, describing a tea tasting and class I held at our bookstore before we added the tea bar.
When I was a kid, tea was something that came in bags with a little tag that said “Lipton.” Visits to a Chinese or Japanese restaurant introduced me to the “other” kind of tea: green tea. The first time I ordered tea in a nice restaurant, I encountered the fancy presentation box, containing exotic varieties of tea like chamomile, Earl Grey, English breakfast tea, and Constant Comment. In high school, I drove a delivery truck for an office supply store in Boulder, Colorado, and one of my stops was Celestial Seasonings.
By that time, I was probably a typical American tea consumer. I classified teas into herbal, green, medicinal, and “ordinary.” Not until quite some time later did I discover just how much I was missing, and in an April tea tasting at Red Lodge Books, I tried to pass on a bit of what I’ve learned. This article is a distillation of the talk I gave that day.
All “true” tea comes from the same plant: Camellia sinensis. There are three major variants. The China bush (var. sinensis), the Assam bush (var. assamica) from India, and the Java bush (var. cambodi). Within those broad categories are over 1,000 individual subvarieties. Just as red climbing roses and yellow tree roses are both roses, all of these subvarieties are still Camellia sinensis, the tea plant.
There are six generally-accepted ways to process Camellia sinensis leaves, which produce white, yellow, green, oolong, black, and pu-erh. Yellow tea is so rare that I decided not to cover it. All “true” teas have caffeine, including the delicate whites and greens. Red tea (a.k.a. African rooibos), which I’ll discuss next month, is made from a different plant that does not have caffeine.
White Tea
White tea is the least-processed, and generally lightest and sweetest-flavored tea. It is typically more expensive than black or green teas, and is recognized as having significant health benefits. It is brewed at a lower temperature, and steeped for a short time. The leaves can be re-used, to make 2-3 cups of tea from one teabag or container.
The white tea we tasted at the bookstore was Rishi’s organic Silver Needle (Bai Hao Yin Zhen), from the Fujian province of China. This tea was voted the best tea in the world at the 2008 World Tea Championships, and the best white tea in 2009. The taste is very light and subtle, and there is a wonderful jasmine-infused version available as well.
White teas start out as young budsets (an early bud with or two leaves). After picking, they are “wilted” indoors to get some of the moisture out, and then baked or panned. After a light rolling of the leaves, they are dried and packaged for shipment.
Green Tea
Green tea is the traditional tea of China and Japan. It has long been lauded for its healthiness, and intricate ceremonies have been developed around its preparation. People study the Japanese Tea Ceremony for years before performing it publicly. Like white tea, it is brewed at lower temperatures, and can yield 2-3 infusions.
The green tea we tasted was an organic Sencha from the Kagoshima Prefecture of Japan; voted the best green tea in the 2008 championships. It is a very traditional green tea, grown in volcanic soil, yielding a deep almost grassy flavor.
After picking, the leaves are steamed or panned, rolled, and then dried. Sometimes, they’ll be formed into balls or other shapes before drying.
Oolong Tea
Oolong is a very highly-processed tea; one of the most complex to produce. It is generally flavorful and rich without the bitterness often associated with black teas. Unlike green and white teas, the leaves are partially oxidized, which darkens the color and intensifies the flavor.
We tasted an organic Wuyi Oolong. The Wuyi Mountains in Northern Fujian are where oolong tea was first produced, and this variety has a roasted aroma, complex flavor, and sweet finish.
To make oolong tea, the freshly-picked leaves are first wilted (partially dried) in the sun, and then again indoors. They are tossed in a basket to bruise them, and then partially oxidized (typically anywhere from 30-70%). After oxidation, the leaves are baked or panned, and then rolled. The final steps are drying and firing, which produces the smoky aroma.
Black Tea
By far the most common type of tea in Europe and India, black tea is usually brewed hot and strong. Many cultures serve it with milk, sugar, or both to mitigate its inherent bitterness, and it is often flavored with lemon, orange, or other spices (Red Lodge Books has a fascinating vanilla black tea). Black tea flavored with bergamot is known as “Earl Grey.” Black teas are also the basis of English and Irish breakfast tea. Unlike white, green, and oolong teas, black teas are generally only infused once: use the leaves and discard them.
At the tasting, we had Rishi’s organic fair-trade China Breakfast, which won “best breakfast blend” at the 2009 World Tea Championships. It’s rich, malty, and robust; great for the first cup of the morning.
Black teas are usually made with an indoor wilting, followed by a cutting or crushing step. This can range from a light crush to a full “CTC” (crush-tear-curl). This exposes more of the leaf’s insides to assist in oxidation. Black teas are 100% oxidized, yielding higher caffeine content and stronger flavor. Following oxidation, leaves are rolled and dried.
Pu-Erh
This is probably the least familiar process to Americans, but it has been around in China for centuries. What differentiates it from black or oolong tea is a fermentation step at the end of processing. Although the term “fermented” is often incorrectly used instead of “oxidizing” for black teas, pu-erh is the only variety that is actually fermented.
A cake of 2009 Tong Qing Tang Pu-erh tea.
If you’ve ever had a mulch pile, you’re familiar with the process: plant matter is piled up wet, and left alone. The inside of the pile grows hotter as it ferments. Unlike most teas, which are served as fresh as possible, pu-erh is often compressed into cakes (sometimes immense bricks) that can be stored for years. Century-old pu-erh cakes are sold at auctions for thousands of dollars.
Pu-erh is brewed in boiling hot water, and can be re-infused at least 6-8 times. I’ve used leaves ten times and still gotten good flavor from the tenth infusion.
At the tasting, we had a classic loose-leaf organic fair-trade pu-erh from Yunnan, China. The flavor was earthy and rich. The description may seem off-putting to some, but it’s definitely worth trying a good pu-erh.
Tea Absolutists (a.k.a. Tea Nazis)
There are a lot of types of tea people. Tea purists, tea snobs, tea ceremonialists, tea sippers, tea guzzlers, tea herbalists, tea totalers (okay — just kidding on that last one). Today’s commentary is on the tea absolutists.
I, like most tea drinkers, have my favorite way of preparing each of my favorite teas. You may well do it differently, and I really don’t care. If you walk into my tea bar and ask for a cup of lapsang souchong, I will make it the way I make lapsang souchong for myself: 1 tbsp of leaves per 16 oz pot, 195-200 degree water, 3:00 steep time, no sweetener or milk. If you then decide that you’d rather use a bit less tea and steep it a bit longer, and perhaps add some stevia and cream, that’s fine with me.
The absolutist, however, doesn’t just have an opinion on how he wants his tea. He has an opinion on how you should have your tea! You see this all the time in books and magazine articles, and on the websites of many tea suppliers. “Use 5 grams of this tea for your 16-ounce pot (because we love mixing metric and English units). Use 195-degree water, and steep for 3:45. Dammit, don’t you dare steep it for 4 minutes or it will become too astringent. And boiling water will scald it. And if you add lemon, you’re a heathen. An uncultured heathen, I tell you!”
The absolutist, however, doesn’t just have an opinion on how he wants his tea. He has an opinion on how you should have your tea!
I am especially amused by the water temperature absolutists. They’ll come into my tea bar and ask if my water is 210-212 degrees. “Well, no,” I explain. “We’re at 5,550 feet altitude. You can’t get water that hot.” They’ll insist that they have to have boiling water, and I’ll explain that water boils at 202 degrees here. Yep, the water is 10 degrees cooler than boiling water at sea level, but by golly it’s still boiling.
I think the absolutist attitude has done much to turn people away from the enjoyment of tea. If someone says they don’t like black tea because it’s too bitter, it’s probably because they’ve been pouring leaves (or dropping bags) into a pot of boiling water and leaving them in there for ten minutes. I’ve had several people who “didn’t like black tea” get very excited about a nice first flush Darjeeling steeped for a scant two minutes. There’s still plenty of flavor, just a tiny bit of astringency, and barely any bitterness.
Darjeeling absolutists are probably starting up their flamethrowers as they read this. “How can you steep it for only two minutes? You’re not getting any flavor out of it!” A quick Google search shows recommendations anywhere from 90 seconds up to 6 minutes for a first flush Darjeeling (I’m one of those 2:00 to 2:15 people), and the majority of them are convinced that their answer is the one and only true answer. If everyone else just followed their procedure, the world would be a happier place.
The correct steeping time for your tea is the steeping time that produces a cup of tea that you like. You. Not me, not the tea expert in the shop down the street, not the guy that wrote that book on your coffee table (or tea table, I suppose). Ditto water temperature. Ditto quantity of leaves. Ditto sweetening. Ditto the type of cup. Ditto lemon, milk, cream, or whatever else you may enjoy putting in your tea.
At our tea bar, we really want people to enjoy the teas we serve. We’re not worried about making it “right,” we’re worried about presenting it well and making it so that our customers enjoy it. It’s very easy to lose track of how long your tea has steeped, so we take care of that for you. We use tea timers and a chart based on our own preferences. But we ask people, how strong do you like it? On their next visit, they may say, “I liked that sencha last time, but it was a bit strong.” So this time, we’ll use a little bit less, and steep for 3:00 instead of the 3:15 that I prefer. Hopefully, the customer will say, “That’s fantastic! Give me a half-pound bag!”
At home, you may prefer delicate porcelain teacups. Here, we use sturdy glass mugs, because they show off the tea well, and they don’t break easily. We keep whole milk, 1% milk, soy milk, and half-and-half at the bar rather than telling customers what we think they should use. We have locally-grown honey, but we also supply sugar and several artificial sweeteners.
When people are trying a new tea, I encourage them to let me make them a cup first, and then take an ounce home to experiment. Sometimes the “guess what I tried” stories I hear later give me ideas for new things to do with tea.
So, tea absolutists, I encourage you to be as anal-retentive as you like when preparing tea for yourself. But lighten up and let everyone else enjoy their tea any way they like. Please?
I am a 
Tea With Gary 