stock man said

What about fluoride?

Some weeks ago I saw a documentary about flouride and its effects on health, and one of the products they said contain a lot of flouride is tea (and the older the leave, the higher the amount of it).

Does anyone have more info about it?

12 Replies
Cwyn said

Brick heicha tea from areas like Hunan does have fluorine, and Tibetans drinking a large and concentrated amount (boiled down) has led to infamous “black teeth.” The recommendation for adults for Hunan or Sichuan is no more than 17g/day. Some minority tribes well exceed this amount. However, a normal session of 3-7g prepared gongfu infusion method, as opposed to boiling down the leaves for several minutes, is perfectly safe.

It’s true that much older leaves are used for heicha tea. Puerh from Yunnan, on the other hand, is made from primarily new growth which has low levels of fluorine and is not normally a concern.

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stock man said

Yes, that’s it, tea tips have lower flouride concentrations.

One of my concerns is tea bags, as I drink a strong cup of yorkshire breakfast tea every single day. Are tea bags made with old leaves or new ones? (as most of them are made of dust I don’t now wth are they using).

Cwyn said

Most English tea bags use tea varietals from India, Sri Lanka and other places. The bushes used are generally very young. BTW I drink Yorkshire bags myself, a friend in the UK sends them to me. I drink two bags, each steeped twice.

stock man said

I see…

BTW, I’ve just bought a box of 80 taylors of harrogate gold bags. I’ll make a review once it arrives.

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Some days I reach for my box of Yorkshire tea.
One bag steeped twice, more of everything if I use a Brown Betty teapot.

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Thanks for the idea to look into this; I did a bit of reading and wrote a post about it. It didn’t work to bang out a simple summary but it did come together as a more comprehensive review. I couldn’t pin down if types of hei cha really are a higher risk but data certainly points out why that might be true: older leaves contain a lot more fluoride, potentially in the range of 10 times that found in most prepared teas.

It went long reviewing what normal recommended amounts for intake are, and limits, levels in treated water, risks related to natural water sources, with lots of research on tea added to that. All of those other factors tip the balance of whether fluoride in tea is a beneficial supplement or a health risk.

To summarize: 3 to 4 milligrams of fluoride a day might be helpful, for an adult (or potentially too much for someone sensitive to the effects), and over 10 mg isn’t recommended. Both drinking a lot of tea and input from drinking only treated municipal water are down around 2 mg / day, or maybe a little over, so most people are fine. That post:

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An update: I summarized that earlier content for submission for a TChing article, which I’ll cite at the end. I added a reference to amounts in specific teas I found at the end of the version in my own blog post, which generally matches the one from an Indian study cited in the first. A lot of teas contain well under 1 mg / liter for a brewed value, and less are in the 3 mg / liter range in that later reference.

Related to that last post comment here I mentioned 10 mg / day as a daily limit, but that is the old general value for a limit, with the newer one .08 mg / kg body weight / day (an EPA version). Some quick math: that limits 100 kg person (220 pounds; a big person) to 8 mg / day, and a human half their size to 4. Lots of different sources propose different daily limits though (an earlier EPA reference had limited daily intake to 4 gm, per one article); best to not hold to any one if you’re concerned about it and read around instead.

I tried to review hei cha, given Cwyn’s input prior, and a post in Matt Cha’s blog links to a couple of studies (I’ll just cite one study here, since the results are similar). Those cite brewed tea fluoride levels of 2.59 mg / liter for Tibetan brick tea, which is actually slightly lower than the value for Lipton tea bags, or for granule-format Indian CTC tea in the one study in that first post. I think the issue might be drinking lots of tea and also cooking with it (their staple food zanba is roasted qingke barley prepared with tea). Those links:

Rasseru said

Thanks for the good research John.

Sure; thanks for the thanks. It was interesting getting into all that. It probably maps onto how a lot of those types of issues go, that there really is something to the concerns but the way it all gets split into people thinking fluoride is completely safe versus unsafe (or even a government conspiracy) becomes a false divide, based almost entirely on unexamined assumptions. It seems quite safe within a limited range, only perhaps a little unsettling that the official version of that range might change over time.

The studies that map a correlation of reduced IQ to fluoride intake are a little unsettling, and I didn’t really get into that. I would probably limit the exposure for my own kids, although I’d still let them drink treated water. The funny part about that is the benefit for teeth is probably highest at young ages while teeth are developing (not that I ran across that idea; that part is common sense).

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Dr Jim said

It seems that we need to count the fluoride in the water used to steep the tea. I live in Massachusetts, and our water supply has 0.7 mg/l. If I drink 2 liters of tea a day, plus 2 liters of water (and yes I really do drink that much) then I’m already at 2.8 mg. Now I have to figure out how much more fluoride the tea added to the water (not to mention toothpaste and the fluoride rinse my dentist recommended). I don’t have a lot of margin. On the other hand, I’m an old man and my bones are already shot.

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Table 2
Fluoride concentration (mg/l) in tea and herbal infusions
Type of tea and name Origin/brand Time of brewing (min)
5 10 30
Black tea
Black Yunnan Gold China 0.32 0.53 0.81
Black Assam India 0.79 1.01 1.12
Black Darjeeling India 0.57 0.65 0.71
Black Assam FOP India 1.15 1.36 1.52
Black High Grown Sri Lanka 0.72 0.91 1.08
Black Maloom Nepal 0.51 0.57 0.63
Black Golden Tippea Kenya 0.93 1.39 1.49
Black Georgia 0.89 0.99 1.07
Black Ceylon Gold Dilmah 1.08 1.28 1.34
Black Telety 2.26 2.49 2.69
Black Earl Grey Tetley 2.62 3.03 3.32
Black Posti 2.25 2.32 2.61
Black Assam Ahmad Tea 1.43 1.59 1.75
Black Lipton 2.76 3.28 3.42
Black Earl Grey Lipton 1.22 1.44 1.50
Black Cardamom Dilmah 2.13 2.29 2.45
Black Yunnan ZAS-Pol 1.09 1.37 1.57
Black Vanilla Dilmah 2.03 2.32 2.61
Black Ygara Astra 4.54 6.13 6.87
Black Darjeeling Himalaya Astra 0.82 0.91 1.15

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The table from one of the references articles at the end of the post, here:

You raise two good points, the first being that multiple sources of fluoride intake could elevate it to being a concern, where if you just drink treated water or only drink tea as a source it’s probably not a risk at all. And the exposure risk is a long-term issue, so someone taking up a tea habit in their 60s might have already cleared the concern by limiting the time-frame. In that table it’s interesting to note that Lipton is the second highest recorded level, and Tetley Earl Grey the third. Ygara Astra black tea is that other outlier; measuring 4.5 mg / liter if brewed for five minutes, probably a good tea to avoid. Pu’er is all low, in the other part of that table, all four versions around or under the range of 1 mg / liter.

Returning to your question, assuming a limit of .08 mg / kg body weight per day (not the only limit cited, but a latest reduced version) if you weigh around 70 kg as I do (155 pounds) the long term limit is 5.6 mg / day. You’ve consumed half by water intake (assuming one disregards toothpaste and cooking water), and drinking any tea with 1.4 mg / liter or less still stays at or under that limit. You’re probably fine, unless you drink Lipton tea, then you’re over by 1.3 mg / day. So probably still ok, although it’s worth considering switching to a better loose tea, for multiple reasons.

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