Why does Tea Keep Us Awake?

Bhodi-Dharma chewed tea-leaves to stay awake. Why? It is because there is caffeine in tea-leaves. There are other drinks with caffeine in, too, for example, Coca Cola and coffee.

Many people have a cup of coffee or tea in the morning before they go to work because caffeine stops them feeling sleepy. Students also drink coffee, tea or Coca Cola when they are studying because these drinks keep them awake.

In some places people do not drink tea, coffee or Coca Cola when they are sleepy They chew cola nuts because there is caffeine in cola nuts.