"This work contributes to understanding the function of tea on creativity and offers a new way to investigate the relationship between food and beverage consumption and the improvement of human cognition," the report states.

"Two biological ingredients, caffeine and theanine, have beneficial effects on attention, which is an indispensable part of cognitive function.

"But the amount of tea ingredients our participants absorbed was relatively small.

"Also, theanine facilitates long-term sustained attentional processing rather than short-term moment-to-moment attentional processing."

Still, there's no reason why you can't cite the study to legitimise your four-cup-a-day habit.