Green Tea Dosage

Does anyone know the optimum/highest safe dosage of green tea in terms of EGCG content?  

Based on the research I've done there are 3 primary risks associated w/ high dose green tea (neglecting caffeine):

1.  increased bleeding time
2.  increased risk of birth defects (neural tube defects due to folic acid antagonism---so pregnant women shouldn't take green tea)

3.  increased risk of bladder cancer


My main concern is #3.  If anyone has information as to the highest ECGC dosage/day in terms of risk/benefit terms, particularly related to bladder cancer.  

I've also read that once daily dosage is better than multiple daily dosage.  Any comments on this would also be welcome.  

[samroad]

Addition to post:

Actually I've read mixed reports regarding green tea and both pancreatic and bladder cancer.  Some say high dose green tea increases risks of these cancers and some say it decreases it (go figure).  

It seems somewhat established however that green tea does reduce the risk of esophageal cancer and probably has no effect on stomach cancer.  

Overall the benefits in terms of antimicrobial activity, cardiovascular and cancer protection are significant.  

I'm just trying to find the best dose (in terms of EGCG content) in order to optimize green tea's benefits and minimize it's risks.  Any input would be appreciated.