Ordinary tea appears to have a range of diverse properties, mostly caused by the contained catechins. Thus tea is an antibiotic, anticoagulant, antidiarrheal, antiviral agent, an artery protector and a diuretic. Green tea is richer in catechins than all other teas, and therefore it is the most potent agent.
Caution: Too much tea can increase anxiety, insomnia and the symptoms of PMS. Tea also has a high oxalate content, and should be limited by persons prone to form calcium oxalate stones.