How does caffeine make you more alert and work as a cognitive enhancer if it reduces blood flow to the brain?

Question

I’ve just read that a 250mg dose of caffeine can reduce blood flow to the brain by 22%-30%.

It seems counter intuitive to me that a chemical that restricts blood flow to the organ responsible for all mental operations actually improves our mental functioning.

There’s probably a simple answer but 22-30% seems like it would significantly impair the brain’s functioning

In: 129

Answer 1

Caffeine inhibits receptors which give feelings of drowsiness, which makes you feel more focused and energized. Of course, this isn’t a replacement for sleep.

Edit:

Anyway, blood flow and brain activity are correlated but the actual relationship is very complicated and difficult to study. The amount of blood flow to the brain being affected by caffeine also varies between people.