Side Effects of Drinking Green Tea: Green Tea and Nausea
It's not uncommon for a person drinking green tea to experience nausea and an upset stomach. This is most likely to occur if you drink it first thing in the morning on an empty stomach. The culprit seems to be green tea tannins which stimulate the stomach to secrete more acid. This is a particular problem for people who have peptic ulcer disease or acid reflux problems; and for this reason people with these disorders should probably avoid drinking green tea entirely. One way to reduce nausea that occurs from drinking green tea is to drink it only after eating a meal. Adding milk can also prevent nausea, but may inactivate some of the healthy polyphenols.