For more details on this topic, see deuterium. A deuterium atom contains one proton, one neutron, and one electron. 2H (atomic mass 2.013553212724(78) u), the other stable hydrogen isotope, is known as deuterium and contains one proton and one neutron in its nucleus.
The caffeine in green tea, especially when taken in large amounts, can worsen diarrhea. Irritable bowel syndrome (IBS) : Green tea contains caffeine. The caffeine in green tea, especially when taken in large amounts, can worsen diarrhea and might worsen symptoms of IBS.
2 doctors agreed: Green tea: Green tea is generally very safe & has positive effects on health. If you drink five or more cups of caffeinated green tea it can cause an increase in blood pressure for some people, as well as gastrointestinal upset (nausea or vomiting), irritability or insomnia.