Caffeine has received a great deal of attention ever since it was identified as the principal stimulant in coffee 1820. In 1992 researchers found another stimulant compound distinctively different from caffeine that may be responsible for coffee's gastrointestinal effects. Coffee often contains a raft of pesticide residues and other contaminants such as nitroseminines, salins and mycotoxins. These carry well-defined health risks and some are carcinogenic. We'll discuss the problems associated with coffee cultivation in chapter 7.