Caffeine, the most widely consumed psychoactive substance in the world, is the best known ingredient of coffee. Its beneficial effects on the human body has been researched quite well, but coffee as a whole is a complex beverage with a thousand different substances. Some studies argue that decaf and caffeinated coffee may have the same health effects and suggest that itâ??s not the caffeine that is responsible for most of coffee's health benefits.Instant coffee contains slightly less caffeine and more acrylamide than regular coffee, but it contains most of the same antioxidants. Overall, instant coffee is a healthy, low-calorie beverage that is linked to the same health benefits as other types of coffee. High caffeine levels in your blood reduce the risk of Alzheimer disease. It also lowers risk of dementia.