|I've covered this topic on my cruise ship presentations on coffee.
Caffeine is the most widely consumed psycho-active substance in the world!
Caffeine is not the work of Satan, nor the product of some mad scientists working in a chemistry lab; rather, it’s the result of millions of years of plant evolution.
All plants build a variety of compounds including enzymes. Many of these molecules serve as a defense against enemies of the plants—large and small.
Building caffeine is an expensive process (energy-wise) for the plant, so why do they do it?