It is common practice for a lot of people to have coffee in the morning with the belief that it helps keep them awake. Well, if you are one of those people, you will be glad to know that coffee does indeed keep you alert and improves your overall mental performance. Taking black coffee in the morning helps boost memory power and keeps the nerves in check. The amount of caffeine in coffee has also been proven to improve your mood and increase your metabolic rate in addition to the fact that for people who like to exercise, it increases their performance during workouts. Antioxidants rich in coffee decrease your chances of getting diabetes and liver disease. Coffee can also help clean your stomach by flushing out toxins as it is a diuretic beverage.