Caffeine is a popular substance that naturally occurs in tea, coffee and chocolate but can also be added to products such as soft drinks and medications. Over 80 percent of adults in North America regularly consume caffeine, according to the Centre for Addiction and Mental Health. Caffeine is well known as a stimulant to the central nervous system, and many who drink caffeinated beverages do so with the intent to stay alert when they are feeling fatigued.
Effects
Caffeine is in the xanthine chemical group alongside a chemical called adenosine. Adenosine, which naturally occurs in your brain, typically binds to your brain’s receptors, slows down cell activity and causes you to feel drowsy. Caffeine so closely resembles adenosine that your brain doesn’t recognize the difference between the two, and caffeine can bind to adenosine receptors. When caffeine blocks adenosine, your brain doesn’t sense exhaustion and it receives a gradual stream of alertness-inducing adrenaline, according to a 2011 article in “Psychology Today.” You typically experience caffeine’s greatest effects within 30 minutes to an hour, and the extra pep boost may last up to four to six hours, according to Health Services at Columbia University.
Related Perks
Caffeine can enhance your ability to perform simple intellectual activities by reducing fatigue, but it acts in more places than your brain. It elevates your heart rate, helps your muscles contract with ease, constricts your blood vessels and improves your breathing by relaxing your air passages, according to the University of Washington. These effects may increase your endurance in physical activities. Caffeine will not, however, help increase your sobriety if you have had too much to drink. Though it may reduce drowsiness related to alcohol, it can’t improve your ability to concentrate or coordinate movements when you are intoxicated.
Negative Effects
The same effect that keeps you alert when you consume caffeine may lead to unwanted side effects if you have more than about 500 to 600 mg of caffeine a day, according to MayoClinic.com. For instance, having too much caffeine within hours of sleep may lead you to have trouble falling or staying asleep. Repeated sleep disruptions may cause you to feel fatigued in the daytime, which may increase your dependency on caffeine. The cycle can be vicious and difficult to break. Immediate side effects of having too much caffeine include nervousness, irritability, stomach problems, a rapid heartbeat and muscle tremors.
Alternatives
Consuming caffeine isn’t the only way to increase your alertness. If you’re trying to cut back on your caffeine intake, making some simple lifestyle changes may reduce your dependency. First, always get a good night’s rest – usually seven to eight hours a night for adults – and take a brief nap during the day if you feel groggy. Also, cut back on your intake of saturated fat and alcohol and increase your intake of fresh plant-based foods such as fruits, whole grains and vegetables. Avoid skipping meals or eating large meals far apart, as your body will lose energy when you aren’t well nourished and will devote much of its energy to digesting a large meal. Finally, taking a brisk 10-minute walk can get your heart pumping and boost your alertness when you need a quick pick-me-up.
References
- MedlinePlus: Caffeine in the Diet
- MayoClinic.com: Caffeine: How Much is Too Much?
- University of Illinois McKinley Health Center: Caffeine
- Health Services at Columbia University; Caffeine’s Effects on Health; 1999
- Centre for Addiction and Mental Health: Did You Know… Caffeine
- University of Washington: Effects of Caffeine on the Nervous System
- “Psychology Today”; The Case for Caffeine; K. Schreiber; 2011
- Argosy University; Caffeine: Your Brain on Stimulants; 2010
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