"People diagnosed with high blood pressure and/or heart disease should not drink Tea. The caffeine from the Tea will cause blood pressure increase and make the heart beat faster.
People who have weak stomach or have stomach problem should not drink Tea on an empty stomach. If you drink tea tea with an empty stomach, the tannic acid from the Tea will affect your stomach’s digestive function and lose the ability to absorb Vitamin B2 and iron, thus causing stomach pain."
that sounds scary, Archus.... maybe some baking soda & water to settle your stomach?