I've always known this quote is true:
"There is no trouble so great or grave that cannot be much diminished by a nice cup of tea."
- Bernard-Paul Heroux
A recent article published in Psychopharmacology journal indicates that drinking tea (black tea) contributes to lower stress levels. Green tea was not tested. Read the abstract to learn more.
From the conclusion statement: "Compared with placebo, 6 weeks of tea consumption leads to lower post-stress cortisol and greater subjective relaxation, together with reduced platelet activation. Black tea may have health benefits in part by aiding stress recovery."
Having an interest in good research, I must point out that the study was funded by some pretty neutral-sounding organizations (like the British Heart Foundation). At the same time, partial funding came from Unilever - which owns Lipton Teas.