Monday, April 30, 2012

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?

1 comment:

  1. I think not all companies should carry studies on contents of different molecules (caffeine, antioxidant, etc.). Such analysis can cost a lot, so probably only well established companies can benefit from that.

    However, I think consumer education is the key. There are several studies on caffeine content. However, caffeine does not have the same physical effect in different teas, and other molecules interact in our body, either to delay the stimulant effect of caffeine, or have a soothing effect which balance with stimulating effect of caffeine. Thus, teas with similar caffeine content will not have the same impact on our body.

    The key for tea companies is to guide customers through that so to give the most neutral information. I hear often at the local tea house where I by my tea "I want a tea with high antioxidant", "I want a low caffeine tea", etc. Just explaining the differences and subtleties will guide the buyer.

    I buy tea because I like tea, but I'm aware of the health effects of the different teas I have. I have reached that through my own research and curiosity, but also while talking to the staff at my local tea house (Camellia sinensis, quoted in the post). I think that's the key.