black tea like Lipton's, or green tea
like Bigelow's, I think would be safe. The antioxidant properties of tea
is good science, lot's of studies to back that up. I wouldn't really do it in excess on treatment though because it might be too much of a diuretic type of effect. I also would still only drink in as part of your normal fluid intake during the day, but not as an excessive type of thing.