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.
The green tea tannins increase stomach acid. So, if you drink green tea before eating, it may give you a stomachache, a nauseous feeling, or cause constipation. It is best to drink green tea after a meal or in-between meals. People with peptic ulcers or acid reflux should be especially careful. You can try adding milk if it continuously causes stomachaches.