ORF said:
Maybe the correct and enough general question should be: What makes caffeine (from tea) work slower than coffee?
I have a couple of books on caffeine (
Buzz and
The World of Caffeine) and have read many journal articles; but I haven't come across anything that says caffeine itself works any differently in coffee vs. tea. And the article you cite agrees with me, if you read the last paragraph before their sources - they mention that
maybe L-theanine (an additional component of some teas)
might make some difference in the tea experience, but they're not really convinced. My own opinion is that L-theanine has a lot of hype associated with it, e.g. vitamin/herb/supplement companies like to sell it as a pill for relaxation or calm.
@jim mcnamara mentions that oxidized catechins increase caffeine absorption in the gut, which certainly wouldn't equate to tea having a "slower" effect; I have done a quick Google but don't immediately find information about this phenomenon.
My own view would be that people who try to persuade you that the caffeine in this or that sort of beverage has a slower or gentler or less harsh effect than caffeine in coffee are either deluding themselves, or if they are selling it as a product, trying to delude other people. You will sometimes see yerba mate praised for being gentler than coffee but still conducive to alertness, for example. This is all pretty much BS, as what really matters with caffeine is how much you ingest; e.g. tea tends to contain less than coffee, but still has plenty. Other factors that matter are when you take it; how habituated you are to it; and how inherently sensitive your body is to it. People vary quite a bit in terms of sensitivity.