I like my herbs in the most natural form possible. Here is some info that might help:
"EGCG in decaffeinated green tea
According to syndicated health columnist Karen Collins (who is also a registered dietitian with the American Institute for Cancer Research in Washington, D.C.), decaffeinated green tea has only one-third as much EGCG as ordinary green tea.
EGCG, which stands for epigallocatechin gallate, is considered the most potent disease-fighting antioxidant in green tea.
Some of you may be concerned about your caffeine intake, but remember: Ounce per ounce, not only does green tea have only about a third as much caffeine as coffee, but the polyphenols in green tea slow the body's uptake of that caffeine. Consequently, green tea drinkers don't experience the same "spike" in caffeine in their blood streams, or suffer from the same "crash" that comes later.
In other words, green tea drinkers are more mellow!