The effects of coffee and tea differ due to the different ratio of caffeine and the presence of a special amino acid in tea — L-theanine, which softensthe effect of the stimulant.
The difference between coffee and tea isn't just the caffeine content.
Scientists analyzed 20 commercial teas, and found that their caffeine content ranged from 14 to 61 milligrams per serving. Coffee may contain significantly more caffeine, but the amount depends on the variety and volume ofthe beverage.
According to the University of Washington, double espresso typically contains 60 to 100 milligrams of caffeine, while the average cup of coffee is about 65 to 120 milligrams.
One of the key ingredients is L-theanine, an amino acid naturally found in the tea bush (Camellia sinensis). In nature, it is relatively rare and is found mainly in tea leaves and a small number of fungal species. Coffee beans do not contain L-theanine, which makes tea a unique drink that simultaneously provides the body with both caffeine and this amino acid.
Recall that the American Heart Association found that drinking 2 to 4 cups of coffee a day is associated with the lowest risk of premature death and improved cardiovascular function.
Although coffee in general contains more caffeine, this difference is not always as significant as many would expect. Scientists believe that another compound found in tea helps explain why the two drinks often cause different sensations.