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?
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”.
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.
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.
"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)
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.