Additionally, tea has other elements (l-theanine, for one) that seem to give it a different profile of side effects. Drinking green tea gradually over the day

Additionally, tea has other elements (l-theanine, for one) that seem to give it a different profile of side effects. Drinking green tea gradually over the day (carrying around a thermos, perhaps) seems to give most of the benefits while minimizing side effects, provided you like tea. The worst aspects of coffee & caffeine come from having a whole bunch at once, then spiking and crashing.