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.
How to Drink Green Tea Without the Side Effects. Though green tea has some health benefits, it can also cause side effects such as nervousness and upset stomach. Some of the problems are due to the caffeine in the tea. Other problems are due to certain substances in the tea.