Last week I was asked by several people to talk about caffeine in tea. Now I preface this by saying that I’m no expert and that I try to look to reputable sources for information.
There is lots of information out there, and a lot of it is put out there by the tea companies. While I’m finding that there are some tea companies that I really like, I haven’t done the real research yet, so I’m hesitant to place my trust in the information that they are providing.
The first place I found that had a bit of information that I trusted was the Mayo Clinic, in an article titled “Caffeine Content for coffee, tea, soda and more.” They list a variety of beverages and include their caffeine contents, but the ones that are particularly relevant are:
- Black Tea – 14-61 mg per 8oz
- Black Tea Decaf – 0-12 mg per 8oz
- Green Tea – 24-40 mg per 8oz
The same article suggests that adults should strongly consider cutting back on caffeine if their total daily consumption equals or exceeds 500 mg and the American Academy of Pediatrics recommends that adolescents get no more than 100 mg per day. For younger children, they recommend that they should not consume caffeine on a regular basis.
Another article at the Mayo Clinic titled “Caffeine: How Much is too Much” recommends that adults limit their caffeine intake to 200-300 mg per day.
I also found a paper that was published in the Journal of Analytical Toxicology titled “Caffeine Content of Brewed Teas” which came out of the University of Florida, College of Medicine. This paper seems to validate the Mayo Clinic’s estimates of caffeine in black tea, both regular and decaffeinated.
Now for the other sources.
Part 4 of The Republic of Tea’s Tea 101 discusses caffeine and tea. Technically all tea has caffeine because to be considered tea, the leaves must come from the Camilla sinenses plant. Decaffeinated teas generally retain a small portion of the caffeine, but the amount is reduced considerably. The amount of caffeine in any given tea really varies depending on the amounts of tea leaves used (as opposed to other things added to the blend) and the method and length of brewing time. Generally the longer the brewing time, the more caffeine in the beverage, which does explain why black teas (at higher brewing temperatures and longer steeping times) usually contain more caffeine than white or green teas (lower brewing temperatures and shorter steeping times).
Adagio Teas has some nice information about caffeine and tea as well, and seems to agree with much of what is presented by The Republic of Tea.
I also found this really beautiful infographic on LifeHacker which tries to lay out the benefits of coffee versus tea. While the format is impressive looking, I can’t necessarily verify the information presented. I will say that the caffeine listed per cup of tea seems to match other sources, most notably those from the Mayo Clinic.
Ultimately, most of what I have read, in both the journal article and the tea sites listed above, suggests that if you are truly hoping to avoid caffeinated beverages entirely you must stick with the herbal blends and tisanes, because they don’t contain any actual tea (Camilla sinensis) leaves and therefore are naturally decaffeinated (barring adding another substance that normally contains caffeine like chocolate for instance).
In the future I’ll try to review decaffeinated and herbal (naturally caffeine free) options and I’ll add a “decaf” tag to the categories so anyone wishing to avoid caffeine can find only those reviews!