Although the leaves in this tea are the same as those in other green teas, gunpowder tea leaves are rolled into small pellets that expand when steeped, releasing the flavor and nutrients. The tea’s health rewards come from flavonoids called catechins, which influence cell-signaling pathways. A large-scale study published in The Journal of the American Medical Association in 2006 indicated a possible link between green tea consumption and a longer life span.