Caffeine is one of the most abundantly consumed stimulants. More than 80 percent of the U.S. population consumes caffeine, with an average intake of 200 milligrams per day, according to the U.S. Food and Drug Administration. Caffeine is present in coffee, tea, soft drinks, chocolate and many other products. Since many products contain caffeine, it is important to know how caffeine affects your ability to stay awake. Overall, caffeine can be used positively in keeping you awake; however, there are some important drawbacks to its use.
Mental Alertness
Like most stimulants, caffeine increases your heart rate and speeds up your central nervous system. More importantly, caffeine reacts in your brain by binding to receptors in the brain that normally tell your body to slow down. By blocking these receptors, your nerves become more active and boost your alertness. Carnegie Mellon University states that doses of 100 to 200 milligrams will result in heightened wakefulness, faster thought and improved coordination. This is why you feel more awake after a morning cup of coffee.
Too Awake
Being alert is important for many jobs, but caffeine can make you too alert or reactive. Caffeine potentially causes irritability and nervousness when the intake levels exceed 500 milligrams. You become too aware of your surroundings and react more dramatically to them. For instance, if a book falls off a shelf when you have ingested a high level of caffeine, it might startle you and cause your heart rate to increase drastically. Caffeine can also keep you awake and prevent you from falling asleep. It takes a long time for your body to break caffeine down and reduce its effects on your body. This makes the potential for insomnia even worse. Furthermore, going to sleep with high levels of caffeine in your body will disrupt your sleep pattern, leaving you less awake in the morning.
Caffeine Content
Many products you consume daily might contain caffeine. It is important to know how much caffeine these products contain to consume an amount that can have a positive impact rather than a negative one. Coffee is one of the highest sources of caffeine. A 5-ounce cup contains between 60 to 150 milligrams of caffeine. Tea contains significantly less caffeine than coffee with just 40 to 80 milligrams per 5-ounce serving. Energy drinks are loaded with caffeine and usually contain 80 to 120 milligrams per 8-ounce serving.
Considerations
Use caffeine carefully if you are trying to keep yourself awake. Individual tolerance levels to caffeine vary; you may need a smaller or larger dose of caffeine to be in the right state of alertness. The best method is to start by trying smaller amounts of caffeine until you find the amount that works best for you. Daily caffeine use also will gradually reduce caffeine's effects on your alertness. You will need more and more caffeine to produce the same level of alertness. This can lead to insomnia as more caffeine in your system means it takes longer to clear from your body before bed. Use of caffeine to help wakefulness should be kept to occasional use. Consult with your doctor to discuss if caffeine consumption is safe for you.
References
- National Institutes of Health: Caffeine
- Food and Drug Administration: Medicines in My Home: Caffeine and Your Body; 2007 (PDF)
- Carnegie Mellon University: Caffeine Effects
- MayoClinic.com: Caffeine: How Much is Too Much?; March 2011
- University of Washington: Effects of Caffeine on the Nervous System
- University of Illinois McKinley Health Center: Caffeine
- University of Arizona: Caffeine (PDF)
- KidsHealth: Caffeine Confusion
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