Nowadays it is possible to buy “de-caffeinated” coffee, and millions of people drink this rather than “regular” coffee. What is caffeine, and why do some people try to avoid it?

The roasted coffee bean is so full of different substances that science has not yet detected all of them. But the best known substance in the bean is caffeine. It is a stimulant and is chemically related to uric acid. caffeine Is not found in a free state, but combined with acids. The coffee bean contains about one per cent caffeine.