Caffeine is almost ubiquitous. Coffee beans, tea leaves, kola nuts and cacao naturally contain caffeine. It’s in many beverages and even, in small amounts, in chocolate.
But while caffeine is safe, it can be harmful — or even fatal — when misused or consumed in excess.
Daily doses of up to 400 milligrams per day appear to be harmless. To put that in perspective, here are rough estimates of caffeine content for:
- Coffee and tea: One cup of brewed coffee has about 100 to 200 milligrams of caffeine, and one cup of white, green or black tea has about 20 to 80 milligrams of caffeine.
- Soft drinks: The caffeine limit for a 12-ounce cola or “pepper” soft drink is 71 milligrams per 12 ounces.
- Energy drinks: The caffeine in energy drinks can exceed 200 milligrams per serving. Note: It is easy to be misled by the heavy caffeine content in small drinks — or the number of servings in a container — and inadvertently consume too much. (The high doses of caffeine make energy drinks unsafe for smaller children.)
read more on health.clevelandclinic.org