Coffee: The New Health Food?

"What caffeine likely does is stimulate the brain and nervous system to do things differently," he tells WebMD. "That may include signaling you to ignore fatigue or recruit extra units of muscle for intense athletic performance. Caffeine may even have a direct effect on muscles themselves, causing them to produce a stronger contraction. But what's amazing about it is that unlike some performance-enhancing manipulation some athletes do that are specific for strength or sprinting or endurance, studies show that caffeine positively enhances all of these things."

How does this brew affect growing minds and bodies? Very nicely, it seems, says DePaulis. Coffee, as you probably know, makes you more alert, which can boost concentration. But claims that it improves a child's academic performance can be exaggerated. Coffee-drinking kids may do better on school tests because they're more awake, but most task-to-task lab studies suggest that coffee doesn't really improve mental performance, says DePaulis.

But it helps kids' minds in another way. "There recently was a study from Brazil finding that children who drink coffee with milk each day are less likely to have depression than other children," he tells WebMD. "In fact, no studies show that coffee in reasonable amounts is in any way harmful to children."

On the flip side, it's clear that coffee isn't for everyone. Its legendary jolt in excess doses -- that is, more than whatever your individual body can tolerate -- can increase nervousness, hand trembling, and cause rapid heartbeat. Coffee may also raise cholesterol levels in some people and may contribute to artery clogging. But most recent large studies show no significant adverse effects on most healthy people, although pregnant women, heart patients, and those at risk for osteoporosis may still be advised to limit or avoid coffee.