Instant coffee contains several compounds which are known to affect the body. These substances originate from the coffee beans, some of which are part of the plant's defense system. While coffee has some health benefits, bear in mind that over-consumption of coffee has toxic effects. One of the main substances in coffee is caffeine, which is considered the world's most common psychoactive drug.
Stimulant and Cognitive Effects Instant coffee is often consumed for its stimulant effect, which is due to caffeine. It is thus popular among students and workers alike. Other substances in coffee, independent of caffeine, stimulate the production of cortisone and adrenaline, two hormones which have stimulant effects.
A study carried out by J. Corley and colleagues at the University of Edinburgh investigated the association between caffeine consumption and cognitive decline in later life. The study involved 923 participants on whom there were intelligent quotient data from age 11.