Lonelsome woman drinking cup of coffee by the window of her living room, looking out at rain falling with a sad look on her face. Selective focus with shallow depth of field, shot through the window.

Source: BBC

George Orwell may have written that “tea is one of the mainstays of civilization in this country” – but even we British have to acknowledge that our national drink is facing stiff competition from the espressos, cappuccinos, and lattes invading our shores.

Despite the dangers of wading into such a charged argument, BBC Future decided to weigh up the relative merits of each drink. There’s no accounting for taste, of course, but we have combed the scientific literature for their real, measurable effects on our body and mind.

The wake-up call
For many, the caffeine kick is the primary reason we choose either beverage; it’s the oil to our engines when we’re still feeling a bit creaky in the morning. Based purely on its composition, coffee should win hands down: a cup of tea has about half the dose (40 milligrams) of the stimulant caffeine that you would find in a standard cup of brewed filter coffee (80 to 115 milligrams). Yet this doesn’t necessarily reflect the jolt of the wake-up call.

Caffeine dose is not the whole story: perhaps our expectations also determine how alert we feel

Dosing subjects with either tea or coffee, one (admittedly small) study found that both beverages left subjects feeling similarly alert later in the morning. Although that study was based on self-reported feelings of alertness, clear differences have failed to emerge in more objective measures of concentration, either – such as reaction times. Indeed, when you dose up on tea made to the equivalent strength as coffee, it actually proves to be more effective at sharpening the mind.

The scientists conclude that the caffeine dose is not the whole story: perhaps our expectations also determine how alert we feel, or it could be that it’s the overall experience of the tastes, and smells, of our favourite drink that awakens our senses.

Verdict: Against logic, tea seems to provide just as powerful a wake-up call as coffee. It’s a draw.

Sleep quality
The biggest differences between coffee and tea may emerge once your head hits the pillow.

University of Surrey researchers found that coffee drinkers tend to find it harder to drop off to sleep at night (Credit: iStock)

Comparing people drinking the same volume of tea or coffee over a single day, researchers at the University of Surrey in the UK confirmed that although both drinks lend similar benefits to your attention during the day, coffee drinkers tend to find it harder to drop off at night – perhaps because the higher caffeine content finally catches up with you.

Tea drinkers, in contrast, had longer and more restful slumbers.

Verdict: Tea offers many of the benefits of coffee, without the sleepless nights – a clear win.

Tooth staining
Along with red wine, coffee and tea are both known to turn our pearly whites a murky yellow and brown. But which is worse?

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