I'm still able to edit the title: care to suggest another version that fits within 80 chars? The title alone fits, one char to spare, but I didn't want to pass off a 4-y.o. paper as if it was pharmacological news.

Possibly something like this: Caffeine and theanine have opposed effect on attention when stressed (2017)

Based on the definition of emotional arousal, stress isn't 100% accurate, but perhaps better than aroused.

[1] https://www.thefreedictionary.com/emotional+arousal

That theanine has a beneficial effect on stress, via cortisol suppression, is a long-standing hypothesis. That it has other effects under the article's umbrella term of "emotional arousal" is one of the interesting novelties of the article for me.

Too late to edit the title now, but for the benefit of next time, I'm still interested in suggestions.

Almost skipped an otherwise interesting topic because of this.

Agreed; in fact, it makes two points that have different impact:

> Consumed together, caffeine and theanine exert similar cognitive effects to that of caffeine alone, but exert opposite effects on arousal, in that caffeine accentuates and theanine mitigates physiological and felt stress responses.

This is inline with the anecdotal evidence about theanine's mitigating effect on caffeine & stress.

So is it fair to say that with tea relative to coffee, you get all the cognitive benefits and none of the arousal downsides (e.g, anxiety)?

Not none. The downsides are moderately decreased in my experience. I’m not sure the amount in tea, I suppose it varies greatly, but I’ve tried several different l-Theanine doses and caffeine mostly still feels like caffeine, just slightly modified.

In my experience, many of the negative effects are greatly reduced. When my dad first brought back a box of PG Tips from a work trip in London, I discovered I could drink like, ten cups and still function. Only moderately burned out.

If I had drank the same amount of coffee I'd've needed to lay down. It was great for all nighters playing Halo multiplayer.

All this time I thought tea's superiority was due to it having "more hydration" or something. This is so interesting to know!

In my experience it’s been that tea gives me far less anxiety, but still a nonzero amount. It doesn’t wipe it out entirely, but it reduces the physiological symptoms of anxiety.

I understood "arousal" to be the emotional sort of arousal, but I see your point.