A study published online in the journal Food Chemistry has found that caffeine in tea can actually be harmful, and in some cases can even be dangerous.
The study found that some types of caffeinated tea contain more caffeine than others.
It found that the most common caffeine content in tea was more than 10,000 times higher than the amount of caffeine found in some other types of teas.
The researchers said that the study was the first to document how caffeine in some teas is different than in others.
The authors said they are not suggesting that the amount or types of caffeine in each tea should be the only criteria used when determining the safety of the tea.
They said that a more important factor for tea consumers is their understanding of the health benefits and risks associated with drinking the beverage.
The Associated Press contributed to this report.