Chemicals found in liquids we drink, foods we eat, medications we take, and cigarettes we smoke can affect sleep. I'm Dr. Nancy Fishback, a sleep disorders specialist with the Sleep Disorders Center, a joint program of Eastern Virginia Medical School and Sentara Norfolk General Hospital. Caffeine, nicotine, and alcohol can disturb sleep. A chemical called adenosine builds up in the brain during waking hours. The levels gradually decrease as you sleep.
Caffeine blocks the accumulation of adenosine in cells and increases wakefulness.
While this is not news to any college student or sailor in the Navy, what you may not know is that caffeine continues to affect your sleep even after the lights are out. Sleep has its own complex architecture that cycles over the course of a night and changes over the years. Caffeine stays in your body long after you go to sleep and can disturb the normal patterns. Avoiding caffeine for six to eight hours before sleep may improve the quality of your sleep. In addition to obvious sources of caffeine such as coffee and colas, you may be surprised to learn that caffeine is present in chocolate, orange soda, and other soft-drinks.