Updates to Article on Caffeine in Tea, And One Company's Studies on Caffeine and Antioxidants

On my recent post Scientific Research I'd Like To See Done on Tea's Caffeine, Vitamin C, etc., I had some useful comments which pointed me to some published studies which I did not know about. Eetu Mäkelä shared a ton of useful studies, a few of which I knew of but many of which I did not. I've begun to incorporate some of the new information into RateTea, but as much of it is not public access and I no longer am within a university environment, it will be a slow process. But already, I've made a few substantive changes to the article on the caffeine content of tea, shown here:

One interesting source:

There is one particular source that I've added that I think might be interesting for people who are really interested in this topic, a study by Camellia Sinensis Tea House on the caffeine content of their teas, which you can find published on their page on Tea and Health. I want to thank Guillaume TR for sharing this study with me. This study reinforces the same general trend that already was established by the article and the other sources, that it is not possible to generalize about caffeine content as a function of broad types of tea (black, green, white, oolong, etc.)

This table, a screenshot of the study, shows a few key points that I like about this study: it shows that the amount of leaf was standardized, and it clearly shows the conditions each tea were brewed in, and it studies the teas using recommended brewing temperatures and infusion times, thus comparing the teas as they would be likely to be consumed, rather than using the same brewing time and temperature for teas that most tea drinkers are going to brew in different ways.

I found this study interesting to read over, looking at the particular values, but I also found the fact that this study was even carried out at all to be rather interesting. Camellia Sinensis Tea House is not the biggest company, and yet they had the resources and drive to carry out this study on a fairly large selection of their teas. I find this encouraging, as it suggests to me that similar studies would be realistic for a large number of tea companies.

A study on antioxidants:

The same company also did a study of antioxidant content. Personally, I'm a little less interested in this study, mainly for the reason that the more I learn about antioxidants, the more I realize that, when it comes to antioxidants, more is not better. RateTea's page on the antioxidants in tea explains more, and the section "Potential Health Effects" on Wikipedia's Antioxidants page goes into more depth about this. One thing is clear though from the results of the antioxidant study: there's no trend of one type of tea (green, black, etc.), or of steamed (Japanese) vs. pan-fired (Chinese) teas, or even of higher vs. lower priced or graded teas being higher or lower in antioxidants. Matcha, however, does stand out for the simple reason that you are consuming the whole leaf when drinking it.

What do you think?

Do you think you can trust the values established by a study like the one provided here? Do you think it would be beneficial in any way (to the business, or to tea culture in general) for tea companies to carry out studies of the caffeine content of the specific teas in their catalogues? Do you think the antioxidant studies are worthwhile, or are you skeptical of them, like me?

Let's Rename Yaupon (Ilex vomitoria) For Accuracy And Marketing Potential

In January, Marlena of Tea For Today wrote a post Yaup, That's Tea about Yaupon, a species of holly native to North America that is, to my knowledge, the only caffeine-containing plant native to North America.

The following photo shows the Yaupon plant, with an eastern bluebird eating its berries:



Yaupon is a close relative of Yerba mate and Guayusa, all three being members of the Ilex genus, which also includes popular landscape plants such as the American holly.

Yaupon's business-killing scientific name: it's all about vomiting.

There is an aspect of Yaupon that makes it highly unlikely that it will ever become popular as a drink: its scientific name, Ilex vomitoria. Does this plant actually cause vomiting, or have something to do with vomiting? Or is it safe to make a beverage out of it?

According to the Peterson Field Guide to Edible Wild Plants, Yaupon is safe to use to make a (caffeinated) herbal tea, so long as the leaves are fully dried, although the plant is mildly poisonous if the leaves are consumed fresh. This is no different from the other hollies: Yerba Mate and Guayusa both must be fully dried before consumption, and are poisonous when raw.

The scientific name for Yaupon, it turns out, has nothing to do with the properties of the plant itself, but rather, with a ritual involving an herbal brew called the black drink, practiced by Native Americans in southeastern North America. This ritual is depicted here on a 16th-century engraving by Jacques le Moyne de Morgues, who produced multiple engravings depicting the ritual and drink:



It is not known exactly what the black drink contained, but it was known to contain Yaupon, possibly as the sole ingredient, or possibly mixed with other ingredients. People would consume large quantities of the drink. In some cases, people would then induce vomiting. However, not all accounts of the black drink or drinks made from Yaupon reference vomiting. It seems reasonable to conclude that the vomiting was induced independently of any chemical constituents to Yaupon, and was associated with the ritual, rather than the plant or the drink produced by it. However, because of its association with these rituals, the name vomitoria was given as the species name for Yaupon.

My proposal:

I would like to propose that the scientific name of this plant be changed. This may seem like a large undertaking, but it is not unprecedented: species names are changed continuously, due primarily to taxonomic reclassification. Tanya Dewey, a postdoctoral researcher at the University of Michigan, in the Zoology department, explains this in her essay What is in a Scientific Name?, when she writes:

When our scientific understanding of animal species and their relationships changes, it may mean that scientific names change as well.

Dewey was writing about zoology but the issues in plant taxonomy are similar. Our understanding of Yaupon has changed. We now know that it does not cause vomiting, nor is its traditional consumption always associated with vomiting. We also know that the name vomitoria is unappealing and effectively kills or at least greatly hinders any potential to develop a market for Yaupon as a commercial product.

What do you think?

Do you think it would be a good idea to change Yaupon's scientific name, Ilex vomitoria, and change it to something more neutral which would both be scientifically accurate and more marketable? What steps do you think would need to be taken in order to achieve this sort of reclassification or renaming? Do you think there could ever be a commercial market for this plant? Have you ever tried it, or known anyone who has tried it?

Caffeine in Tea - It's Not Bad For You

The subject of caffeine in tea is an interesting one. Unfortunately, there is a lot of misinformation surrounding both (a) how much caffeine is in tea, and (b) the effect caffeine has on your body. I have written at length about the caffeine content of various teas, so this post explores the second question.

Public perception of caffeine:

There seems to be a widespread public perception that caffeine is "bad". One way you can tell that this is the case is that a number of tea companies market their teas as being "low in caffeine", whereas teas higher in caffeine are usually not labelled as such, and instead labelled with euphemisms or indirect statements such as "energizing" or "good for starting the day". People want to feel energized, but they don't want to consume much caffeine.

The success of decaffeinated tea, which is often highly inferior in taste to tea in its natural, caffeinated form, is also a testimony to this negative public perception. Some companies even sell decaffeinated green tea extracts, so that people can obtain the "health benefits" of the tea without the caffeine.

In this post I will argue that this attitude towards caffeine is irrational...it's a result of people taking an absolute "good / bad" view of a substance, rather than looking at a key concept: moderation.

People drink tea because of caffeine:

Granted, there are many reasons that people drink tea, inculding flavor, tradition, and expectations of certain health benefits. However, I do believe that, regardless of how many other factors come into play, caffeine is one of the primary reasons people drink tea, if not the primary reason. Tea does contain many other biologically active compounds, such as L-theanine; theanine in particular is known to interact with tea, so the topic becomes a bit complex, but the point is: tea contains caffeine, and people want to consume caffeine.

The evolution of caffeine:

Caffeine is an interesting chemical because it evolved in plants primarily as a biological defense. Caffeine is a poison, probably intended primarily to protect a plant against insects. This is why the caffeine tends to be concentrated in the tender new leaves, which are most in need of protection against being eaten.

Moderation is key:

The activity of caffeine in humans is in some sense a biological accident. A high enough dose of caffeine would kill a human, but a small dose provides a stimulating effect to the body and mind. Many chemicals are like this...nearly all drugs have a lethal dose and a therapeutic dose, and somewhere in between these there are middle doses where unpleasant side effects start to appear.

For caffeine, small quantities can provide a boost in alertness, improved concentration, and improved energy level. But higher amounts, or caffeine consumed at the wrong time, can cause a variety of unpleasant symptoms, both immediate and long-term, including jitters, feelings of malaise, weak and rapid heartbeat, anxiety, and insomnia. Some people are more sensitive to caffeine, either because of their own biology, or because of medications they are taking. But for the most part, the best way to approach caffeine is moderation. So, next time you hear or read someone explicitly or implicitly stating that caffeine is bad, respond by encouraging them to think about moderation rather than in strict good / bad terms.

The Best Teas: Is It Just About The Caffeine?

People who consider themselves tea connoisseurs, or perhaps even just tea enthusiasts, would usually like to believe that they have "discerning tastes", that they appreciate the "finer things in life", and specifically, the finer nuances of flavor and aroma when drinking a cup of tea.

Pictured here is some kukicha, one of my favorite styles of green tea, and one which demonstrates the spirit of this post: kukicha, tending to be low in caffeine, is not a usual focal point of connoisseurs:



This post is about a wrench thrown into the idea that we really have discerning tastes...the wrench is the observation that, at least to a large degree, people seem to seek out teas that are higher in caffeine. Not, mind you, teas they think are higher in caffeine, but teas that actually are higher in caffeine. (Which are two different things, unfortunately, due to the prevalance of misinformation in our society.)

But first I want to digress into the realm of beer and alcohol content, which offers a fascinating analogy of this same phenomenon:

Beer and Alcohol:

I was involved in rating and reviewing beer long before I got involved in rating and reviewing tea. In fact, RateBeer.com, where you can find my profile if you're curious of my tastes in beer, was one of the major sources of inspiration for RateTea.

When I first started using RateBeer, I was so excited about the concept. I loved craft brews, and unlike most people in my age bracket, I had little interest in getting drunk. I saw my use of RateBeer and my passion for craft beers produced by local microbreweries as a rebellion against the dominant drinking culture in our society, which ignores taste and focuses on getting drunk as quickly as possible.

Something raises an eyebrow: Alcohol content and ratings:

After having used RateBeer for years, and drinking, rating, and reviewing hundreds of beers, I started noticing something. Beers with a higher alcohol content invariably received a higher rating on the site. I also noticed this same trend off the site, among people who considered themselves beer enthusiasts or connoisseurs...a large number of them tended towards the Belgian ales and barley wines, with their very high alcohol contents. These brews struck me as more like wine than beer. Personally, I like beer better than wine, and I think this preference is in part because of the lower alcohol content of beer.

As an example, my favorite beer, the Great Lakes Edmund Fitzgerald Porter, with 5.8% ABV (Alcohol by volume) scores a 3.87 with 1223 ratings. The Great Lakes Blackout Stout, a beer that I think is good, but not anywhere near as good, but which has 9% ABV, gets 3.93 (this subtle distinction in score is actually bigger than you might think on the site). Another example, from my hometown, is how Lancaster Brewing Co's Amish Four Grain, with 5.6% ABV is rated much lower than the same brewery's Winter Warmer, 9% ABV. Personally, I think the four-grain is a much better beer.

Back to tea:

I've unfortunately noticed a similar trend among teas, albeit with caffeine in place of alcohol. For example, among white teas, silver needle has more caffeine than bai mu dan, which has more caffeine than shou mei. Guess which ones tend to be more expensive and are often written about by "connoisseurs" as being somehow "better"? Another example...sencha vs. bancha. Another example: tippy black teas (whether Assam, Yunnan, or whatever) vs. their non-tippy counterparts.

Although there's certainly a huge amount of variability, the teas with more caffeine tend to be more expensive, seem to be preferred by people "in the know", and receive better reviews.

Possible confounding factors:

There are other factors that could be contributing to these trends. Some confounding factors that I've thought of are that:

• Tippy teas (more tips / young leaves, less mature leaves) contain more caffeine, and also have a more smooth or delicate flavor, and people may prefer the smoothness or other qualities, so the association with caffeine is accidental.


• Tippy teas are more expensive, and people may be buying into the psychological fallacy that more expensive means better quality.


• Because tippy teas are more expensive, they're more actively pushed by tea companies because of the higher profit margin, and we tea drinkers are simply fooled by their marketing into thinking they're really higher quality.

And of course, it also might be true that people don't actually prefer these teas, that there's just an illusion that they do, again, probably because of tea company marketing (unlike the world of beer, where there is hard data suggesting that people really do prefer the beers with a higher alcohol content).

What do you think?

Do you think that the caffeine content of a tea influences how much people like it, and that people tend to prefer teas with more caffeine because of the caffeine? Or do you think that it could be explained by confounding factors? Or do you think they really don't like these teas at all and it's just an impression caused by tea company marketing?

Your Response to Caffeine

A lot of health websites have data about caffeine. I particularly like one page that the Mayo clinic has, about how much caffeine is too much; their guidelines are that 200-300mg of caffeine aren't harmful for most people, but more than 500-600mg can negatively effect health. But they also remark: Some people are more sensitive to caffeine than are others., and also that How you react to caffeine may be determined in part by how much caffeine you're used to drinking.

This difference is due in large part to the fact that the body develops a tolerance for caffeine. But sensitivity to caffeine is also influenced by other factors, including sex, age, body mass, stress level, and other drug use.

From talking to my friends, I've seen a wide variety of responses to caffeine. Some people say it has little to no effect on them; other people find it really helps them concentrate, and they say they need it to get going in the morning. Some people avoid it because they find its effects unpleasant. Other people say they enjoy its effects but are able to function just fine without it.

How do I respond to caffeine?

My own response to caffeine is hard to generalize about because it is different on different days. In general, small amounts of caffeine tend to make me feel a little better: more focused, a little more positive and energetic. Too much caffeine can make me feel bad, though. Also, there are some ways where I respond very poorly to caffeine. If I'm a little tired, caffeine can perk me up, and if I'm a little hungry, it can stave off my hunger. But I've noticed that if I'm exhausted or ravenous, run down to a more extreme level, caffeine makes me feel terrible: it can make me feel even more sluggish, depressed, and just generally awful. Fortunately, I know these times now and I haven't had this problem for years because I avoid caffeine when I'm feeling tired or hungry beyond a certain threshold.

One reason that I prefer tea over coffee is that coffee has a bit too much caffeine for me. Coffee almost always makes me jittery, unless it's a weaker cup and I'm careful to drink it slowly (which results in lukewarm coffee, not the most pleasant thing). Tea, however, is gentler. Although the caffeine content of tea varies widely, it is almost always substantially more than tea. You can read more about how much caffeine is in various teas on RateTea's page about the caffeine content of tea.

The only problem I've had with too much caffeine from tea has been when I've been idly drinking cup after cup of tea in a Chinese restaurant, and I haven't been paying attention to how much I am drinking, and I have come out wired. Sometimes I also end up this way after tasting a bunch of teas, although I usually tend to space them out so this doesn't happen. But this feeling is usually not as unpleasant as the jitters I get from coffee, probably due to other chemicals in the tea.

I'm always able to function fine without caffeine. I'm a morning person and I wake up just fine, usually before my alarm on days when I have it set. My lowest point in the day is the late afternoon, and I often drink two or more cups of tea some time between noon and 6, so if there's any time of day when I have a noticeable caffeine addiction, it would be this time. But I wonder if it's really that or just that it's a natural low point in the day: I remember feeling this way from when I was a kid, long before I had any regular exposure to caffeine.

So, how do you respond to caffeine?

I would encourage you to either post comments or write your own blog post about caffeine. I think it is useful to see how different people respond to caffeine differently, and I'm curious to read what experiences others have.

Mild Tea - Brewing Tea Weakly

I was in the Newark, DE Farmer's Market today with my friend Jen, and we were looking at fruit, and she laughed as I remarked: "I love smallness." I had chosen the smallest grapes available--today, red grapes--and was eyeing a bag of very small apples longingly. Later, I picked up some mini-bananas:


When I got home, I brewed up a cup of tea, pictured below. It was Upton's Shou Mei Classic Organic (ZW23), one of my favorite white teas. The leaves of this tea are large, and take up a great deal of space. Upton recommends using 2-3 teaspoons of leaf per cup, and even this amount does not produce a particularly strong cup. However, I chose to use only a little more than one teaspoon of leaf, as I wanted a particularly mild cup of tea. It wasn't until I started sipping the tea and contemplating that I realized that there was a strange commonality between how I had chosen to brew the tea and how I had selected fruit earlier at the market.



Shou mei is dark among white teas. While this photo makes this cup of tea look rather dark for a white tea, this tea normally comes out much darker in color, like a dark oolong or lighter black tea. This cup of tea was extremely mild, even outright weak. But this is what I wanted. I didn't want the largest piece of fruit, nor did I want the strongest cup of tea; instead I sought the opposite.

There was little flavor; the aroma was faint, and was earthy and suggestive of autumn leaves, which adds an element of congruence to the photo above. And like the lighting in the photo, there's not much about this cup of tea that stood out; it was highly muted, mellow, and with a hint of warmth, like the reflection of the lamp in the window and on the mug.

Why? Why brew and drink such mild or weak tea?

I feel like I could write pages about the reasons for brewing tea exceptionally weakly, and I hope to write more about this topic in the future. The current culture in the United States is, in my opinion, one that glorifies excess and extremes, and I think this is a shame. While people across America are drinking 20 oz. lattes with extra shots of espresso, I'm drinking a very weak cup of what was an extremely mild tea to begin with. In some senses, I may be brewing my tea weakly, and choosing to write about it, as an act of rebellion against an aspect of American culture that I find unwholesome. But outside this deviant streak in my personality, there are numerous other reasons for my brewing choice that come to mind.

One phenomenon I have come to appreciate is how the subtleness of the aroma forces you to pay attention more closely to the qualities of the tea. I find this promotes mindfulness, which in turn promotes both mental clarity and physical well-being. I also like the noticeable but low amount of caffeine in a cup of weak tea. Spacing caffeine out over a long period of time, I find, promotes a calm alertness and clarity of mind, whereas having too much caffeine at once I find makes me feel "off", and beyond a certain point, actually harms my ability both to focus and to relax.

I can also drink more cups of weak tea than I can strong tea. In the winter, and on cold, rainy days like today, I like to drink hot fluids continually; brewing weak tea allows me to drink a lot more. And sometimes, I don't have a clear reason; I'm just not in the mood for a strong cup of tea.

Try it out.

Decaffeinated Flavored Teas: Why Not Just An Herbal Blend?

I'm both a huge fan and major advocate of loose-leaf leaf, and I will jump on any opportunity to guide casual tea bag drinkers in the direction of high quality loose tea. It's no secret that part of my agenda behind creating RateTea is to draw in people who may have only ever tried the mainstream brands of tea available in the supermarket, and show them what the world of loose tea has to offer. But I still feel compelled to write about the mainstream brands from time to time, and now is one of those times.

The other day, I sampled Bigelow's Decaffeinated Constant Comment for the first time. This tea made me ask myself the question: Why? Bigelow's normal Constant Comment is, in my opinion, the best of their flavored teas, and I also think their Orange & Spice Herbal Tea is decent. These three teas are all quite similar, and as I wrote in my review of the decaf Constant Comment tea, I have a hard time understanding why someone would choose that tea over the caffeine-free herbal orange spice blend, which has a very similar overall profile but is bolder and more flavorful.

It's no secret that decaffeination processes extract flavor in addition to the caffeine. Decaf flavored teas tend to be better than decaf pure teas for the simple reason that the flavoring can be added or blended in after the decaffeination process has been carried out, thus leaving the additional flavoring intact. But...given how bland most decaf tea is, if you really want to avoid caffeine, why not just drink an herbal blend based on the flavoring or whatever herbs have been blended in, without any tea?

I guess, everyone has different tastes, and I'm sure there are those who really do like something about the flavor or aroma that decaf tea has to offer. But this is my own personal preference, and I'll continue to only sample these decaf teas out of curiosity, not because I really enjoy them. (Although I am still open to being proven wrong, something that has yet to happen.)

Breakfast Teas

I find it amusing that most "breakfast" teas, whether English, Scottish, or Irish Breakfast, or some of the "China/Chinese Breakfast" blends sold by a number of tea companies, always tend to be strong black teas. While I love many of these and other strong black teas, and I love having tea in the morning, I rarely have these teas for breakfast. These "breakfast" teas I tend to reserve for the late afternoon, usually the last caffeinated cup of the day for me.

My favorite teas for breakfast are bitter green teas. Chun mee and young hyson are probably my favorites, and I also enjoy sencha, especially when it's on the bitter side. My absolute favorite breakfast tea is Upton Tea's Chun Mee Dao Ming. I like a fair amount of astringency in my green tea for breakfast too. In black teas though I like a more mellow tea, like a gentler Darjeeling or a Keemun. I rarely have oolong tea for breakfast, but I have been known to enjoy a raw/green pu-erh, or shou mei white tea.

Do you like breakfast teas for breakfast? Or other teas for breakfast? How about breakfast teas at other times of day?

Tea, Weight Loss, and Control Studies

The Linus Pauling institute at Oregon State University has an outstanding page summarizing recent scientific research on the health effects of tea. This page makes an interesting comment about tea and weight loss:

"It is currently unclear whether tea or tea extracts promote weight loss. Large-scale clinical trials that control for energy intake and expenditure are needed to answer this question."

Are control studies really what we want here?

Western science is based around the idea of controlled studies that isolate one variable and examine the effect of changing that variable when others stay constant. But do controlled studies actually capture what happens in a practical setting? Not at all.

Drinking tea has many mechanisms by which it can influence weight loss through influencing energy intake:

• Tea is a calorie free drink. Tea can be consumed as a substitute for calorie-rich drinks such as soft drinks, milk, fruit juice, or energy drinks. In this case, drinking tea could directly reduce someone's calorie intake.


• Tea can be quite bitter, and is generally not very sweet. Drinking unsweetened tea on a regular basis could change people's tastes, making them more accustomed to foods that are less sweet. This could reduce their calorie intake through reducing refined sugars in their diet.


• Tea contains caffeine, which is known to reduce appetite. Tea also contains a myriad of other chemicals, many of which are poorly understood. It is reasonable that tea could have other effects on appetite and food preferences beyond those caused by caffeine as well. Either way, drinking tea is likely to lead people to reduce their calorie intake overall.

Controlling for energy intake is missing the point. People want to know whether drinking tea will help them lose weight. The vast majority of these people, even those who count calories some of the time, do not effectively control their energy intake the way a scientific study would. People interested in weight loss in the practical setting of their own lives will be more interested in how drinking tea will influence their caloric intake through appetite, food preferences, and any other means. Control studies are missing the point!

Oh, and one last observation--tea extracts do not have the first and second benefit above. Actually drinking tea is necessary to get the full weight-loss potential, since part of the way tea can help you lose weight is through the act of drinking and tasting it, not just through chemicals that you can pop in a pill.

Article on Caffeine Content of Tea

Everyone is always asking me which teas contain the most or least caffeine...so I did some google scholar research and found a couple good articles, which I read, processed, and summarized in an article on caffeine content of various teas.

The basic gist of it...you can't make generalizations about types of tea like green tea, black tea, or white tea containing more caffeine or less caffeine. Rather, the caffeine content varies more from tea to tea. Tippy teas contain more caffeine, and roasted teas contain less, roughly in proportion to the amount of tips, and the amount of roasting.

So...don't believe those claims out there about how white or green tea is "lower in caffeine" than black tea. It's not! Teas of all types are quite diverse and span a broad range of caffeine contents.