Coffee is a mere liquid inside a cup - 98% water and 2% only compose of coffee stuff. Thus, it will keep you awake.
It’s interesting to note that caffeine intercept a chemical that cause us to sleep called adenosine. Not only that, many good stuff such as putrescine that prevent spoiled meat to be poisonous and it is naturally present in coffee. And of course, it is an antioxidant that protects from free-radical damage in our cells. Just a mere liquid that give plenty health benefits.
