Coffee and Health: Beneficial Beans
But the news isn't all good - coffee acts on the brain in similar ways as methamphetamines by increasing dopamine levels, making you feel good while it increases adrenaline, which keeps your body in an alert state. Staying in this state for long periods of time can make you jumpy and irritable.
While it's possible to sleep after drinking coffee, your body may miss out on the benefits of deep sleep. Then when you wake up, you'll need that jolt to get going. And the cycle continues...again, moderation is key in consuming any so-called "healthy" substance. Know your limits.