Can the body absorb caffeine in tea?

[supermif]

I know that coffee and tea have not dissimilar levels of caffeine, but a Dr of Biochemistry that I went to university with asserted that caffeine in tea is chemically unavailable to the human body so cannot be absorbed. Does anyone know if this is correct?

Simon
London

[Duck Duck Goose]

Well, just off the top of my head, how could that possibly be correct? Caffeine is caffeine, chemically speaking, and whether it's in tea or coffee or Coke, it's still "available" to your body. There isn't one kind of caffeine that's found in tea and another kind that's found in coffee, and still another kind that's found in Coke, and only some of them are "available" to your body.

Not to mention the caffeine that's in chocolate...

And if the caffeine in tea is not absorbed by the body, why on earth isn't this amazing biochemical fact being trumpeted to the skies by the various science pundits who appear on the news? Since everybody worries so much about caffeine, why has nobody mentioned that, oh, by the way, you can drink tea and suffer no caffeine ill-effects...

One vote here for "just because he's got a degree doesn't mean he's not an Idjit".

[Squink]

Caffeine is caffeine is caffeine. However, tea usually contains less caffeine than coffee, and some people believe that some of the other ingredients in tea decrese the rate at which the caffeine is absorbed. That's at least a plausible hypothesis as to why tea doesn't give the same kick as coffee.

At one time it was believed that the caffeine in tea was different from the caffeine found in coffee. Accordingly, it was given a different name,'theine', All About Tea. This is no longer the case and the word, theine, is no longer used.
Now it is believed that part of tea's taste results from various polyphenols, modified by caffeine. Additionally, it is believed that the polyphenols slow down the rate of caffeine absorption. At a symposium in the mid-1950's, it was recognized that the combination of the caffeine and "tannin" in tea was beneficial.

Here. Of course, endorsement by a "symposium in the mid-1950's" doesn't constitute hard proof that polyphenols actually do anything in regard to caffeine uptake.

[Squink]

"just because he's got a degree doesn't mean he's not an Idjit"
That's for sure !

[FranticMad]

"Green tea does have caffeine.... In addition, the tannic acid of green tea, which is a part of the polyphenol group, causes the body to absorb the caffeine at a slower rate over a long period of time; the effect of the caffeine on the body is thus much less brutal. "
http://www.healthygourmetstore.com/greentea.html
Note that the above reference is from a store -- and the Tetley site says something similar FWIW.

Studies have found that theanine, an amino acid uniquely found in green tea, decreases some effects of caffeine ("Inhibiting effects of theanine on caffeine stimulation evaluated by EEG in the rat.", Biosci Biotechnol Biochem 2000 Feb;64(2):287-93)

[ftg]

Good grief, I have had many sleepless nights after having that 3rd or 4th cup of tea at a chinese restaurant. I never drink coffee and very rarely caffienated sodas, so tea has been the only major source of caffiene to me. And it definitely causes a buzz.

I can't believe supermif's prof would be dumb enough to believe this. I suspect a qualifier was lost in translation.

[h.sapiens]

Also, if the body can't absorb the caffiene in tea, why make decaffienated tea?

[occ]

It's also been posited recently that some of the kick in coffee may not be from caffeine at all. There was a recent study (no cite, unfortunately, but I read about it first-hand) that demonstrated that *both* decaf and regular coffee led to an increase in (I belive) blood pressure, whereas caffeine alone seemed to have a different effect. Interesting stuff. Also, I can definitely say that coffee packs more of a punch than the so-called "energy drinks", such as Red Bull. They just can't compare, despite having a large amount of caffeine added.

[In Conceivable]

Originally posted by h.sapiens
Also, if the body can't absorb the caffiene in tea, why make decaffienated tea?

Wow. Such a simple question that cuts right to the heart of it.

Please supermif, I want you to ask your professor this and tell us what he says

[InTransit]

FWIW, some teas contain theophylline, (sp?) which acts similarly to caffeine. "Ounce for ounce", however, theophylline is much stronger than caffeine so even though a cup of tea may be lower in caffeine than in the same amount of coffee, the tea could provide more of a kick (& all the caffeine-related effects) than coffee.

[supermif]

Hmm, perhaps I should have phrased the question slightly differently. I was hoping that someone would be able to confirm or refute the claim that caffeine in tea is chemically locked up in some way that makes it difficult/impossible for the human body to absorb.

1. Caffeine is caffeine isn't much of an argument. Cyanide in ionic form is deadly but in organic form is not yet it's the same chemical compound.

2. ftg makes an interesting observation but one that I rarely hear, namely that tea keeps people awake. Do other people have the same experience? Compared to coffee which no-one doubts keeps them wide eyed and bushy tailed.

3. FranticMad makes a good point that the rate of absorption may be a slower due to chemical interference, which may explain why someone who has more regular exposure to caffeine doesn't get the same kick from tea as coffee.

4. The theory that it's not caffeine at all that's responsible for the stimulant effect indicates that this is an area that isn't as well understood as we thought.

5. Does anyone really think that the food industry only make decaf tea because it's better for us? Really? Let's be quite clear on their motivation, it's money. Simply put by pandering to our fears, justified or not, they are able to extract a higher margin as we are willing to pay for that fear to be allayed. There's the organic food that's actually grown with fertilizers, there's low fat yoghurt that's so jam packed with sugars it's worse than the normal stuff, the list goes on.

Finally, I don't know if the guy I went to university with is an 'idjit'. Needless to say, I didn't take everything he said in blind faith or I wouldn't have posted this question in the first place.

[superfreakicus]

Originally posted by In Conceivable
Wow. Such a simple question that cuts right to the heart of it.

Please supermif, I want you to ask your professor this and tell us what he says

why make new coke?

[Aro]

ftg makes an interesting observation but one that I rarely hear, namely that tea keeps people awake. Do other people have the same experience?

Completely anecdotal, but no. I drink tea pretty much constantly all day at work, and a few more cups at home, even immediately before I go to bed.
I have never experienced sleeplessness due to drinking tea. But maybe I'm immune to its effects by now.

[micco]

Originally posted by occ
It's also been posited recently that some of the kick in coffee may not be from caffeine at all.

I saw a study some time back (no cite) that said much of the kick you get from your morning coffee was due to the heat dilating arteries and increasing blood flow to the head. It suggested that people trying to reduce caffeine intake could drink hot water as a useful placebo. IIRC, this was a fluffy news piece rather than an academic study, so I don't remember how much actual evidence they had.

[mmmiiikkkeee]

If I drink tea in more than a few hours before bed I will lay awake most of the night. For me coffee does the same, but isn't as potent.

[Splanky]

So, anyone ever drank cold coffee?

[Duck Duck Goose]

Erowid good enough for ya? Caffeine is caffeine, period. There's no "tea caffeine" and "coffee caffeine". One chemical formula, one molecule, one substance. Caffeine.

http://www.erowid.org/chemicals/caff...hemistry.shtml

Caffeine Chemistry
by Erowid

NAME : Caffeine

CHEMICAL NAME : 3,7-Dihydro-1,3,7-trimethyl-1H-purine-2,6-dione

ALTERNATE CHEMICAL NAMES : 1,3,7-trimethylxanthine; 1,3,7-trimethyl-2,6-dioxopurine; coffeine

ALTERNATE CHEMICAL NAMES : thein; guaranine; methyltheobromine; No-Doz

CHEMICAL FORMULA C8H10N4O2

MOLECULAR WEIGHT 194.19
LD50 194.19
LD50 194.19

They note that that's from the Merck Manual, 12th edition, which entry is Copy and Pasted further down their page.

Now, it's possible that this is the factoid that your prof has gotten hold of and misinterpreted.

http://www.geocities.com/CapeCanaver...d/6202/che.htm

Caffeine is an alkaloid. An alkaloid is defined as any of various nitrogen containing organic bases obtained from plants. Caffeine is one of three types of alkaloids, the others being theophylline and theobromine.

Caffeine- found in coffee, tea, cola nuts, mate, and guarana. Effects include- stimulation of central nervouse system, cardiac muscle, and repiratory system, diuretic delays, and fatigue.

Theophylline- found in tea. Effects include- cardiac stimulation, smooth muscle relaxation, diuretic, and is a vasodilator.

Theobromine- found in cocoa, cola nuts, and tea. Effects include- diuretic, smooth muscle relaxant, cardiac stimulation, and is a vasodilator.

He may be thinking that theophylline and theobromine are different types of caffeine--but they're not. To a chemist, caffeine is caffeine.

http://coffeefaq.com/caffaq.html#Chemically

Caffeine is an alkaloid. There are numerous compounds called alkaloids, among them we have the methylxanthines, with three distinguished compounds: caffeine, theophylline, and theobromine, found in cola nuts, coffee, tea, cacao beans, mate and other plants. These compounds have different biochemical effects, and are present in different ratios in the different plant sources. These compounds are very similar and differ only by the presence of methyl groups in two positions of the chemical structure. They are easily oxidized to uric acid and other methyluric acids which are also similar in chemical structure.

See? He may be thinking that the three different types of methylxanthines--caffeine, theophylline, and theobromine--are actually three different kinds of caffeine.

But they're not. They're three different types of alkaloids.