Coffee drinkers in the United States consume an average of 2.6 cups per day, according to the University of Washington. Coffee's effects on the brain stem mainly from caffeine, the bitter-tasting stimulant that occurs naturally in coffee beans. While caffeine can benefit cognitive function in some cases, it causes problems in others. Gaining an understanding of these effects might inspire you to make wise dietary decisions. To best determine whether coffee suits your wellness and goals, seek guidance from a qualified professional.
Process
After caffeine reaches your stomach and small intestine, it enters your bloodstream. Within 15 minutes of consumption, you can start experiencing its effects, according to the UW. From a chemical standpoint, caffeine belongs to the xanthine group and has a makeup almost identical to the naturally occuring xanthine called adenosine, which plays a key role in wakefulness and sleep. Because caffeine molecules are slightly smaller than adenosine, they bind more easily to neurons, which are excitable cells in your brain. Although caffeine does not trigger the same chemical reactions that adenosine does, it keeps adenosine from effectively quieting your brain. In other words, caffeine does not excite your nervous system but does interfere with the process your nervous system relies on for calmness.
Benefits
In a study published in "Psychosomatic Medicine" in December 2009, the cognitive function and caffeine intake of 923 healthy 70-year-old adults were analyzed. Researchers found a significant positive correlation between coffee intake and reading test scores. In general, higher cognitive scores were linked with coffee consumption and lower cognitive scores with consumption of tea, which contains less caffeine than coffee. And although research is limited, moderate coffee intake, or three to five cups per day, might guard against dementia and Alzheimer's disease. Because coffee and tea contain antioxidants, which also contribute to proper brain function, plant-derived caffeinated beverages might help prevent cognitive decline associated with aging. Low doses of caffeine, or 20 to 200 mg, can produce positive mood effects, such as increased energy, alertness, sociability and happiness. Caffeine also can improve your ability to concentrate.
Risks
Caffeine use is associated with numerous psychiatric syndromes, according to Johns Hopkins Bayview Medical Center, including caffeine dependence, caffeine withdrawal, caffeine intoxication -- which happens when you overdose on caffeine -- caffeine-induced anxiety disorder and caffeine-induced sleep disorder. Excessive caffeine intake and a sensitivity to caffeine increase your risk for these conditions. Caffeine also can trigger nervousness, anxiety or shakiness, symptoms that can interfere with your ability to think clearly. Much of the mood-related benefits associated with caffeine lead to low-grade withdrawal symptoms, such as lethargy and sleepiness, in people who drink it routinely. These symptoms arise after overnight abstinence. Caffeine-related sleep difficulties can interfere with your ability to concentrate and perform well at work or school as a result of daytime sleepiness.
Suggestions
Most adults can safely consume moderate amounts of caffeine, or 200 to 300 mg -- the amount in two to four cups of coffee -- per day. For some people, however, smaller amounts cause adverse effects. If you do not customarily consume caffeine, take certain medications or have an anxiety disorder, your risk for caffeine sensitivity is heightened. To reap benefits of caffeine and avoid potential risks, MayoClinic.com suggests consuming caffeinated beverages mindfully, avoiding caffeine late in the day to avoid sleep problems and, if you decide to cut back, doing so gradually.
References
- University of Washington: Caffeine
- BrainConnection.com: Caffeine, in a Nutshell
- "Psychosomatic Medicine"; Caffeine Consumption and Cognitive Function at Age 70: The Lothian Birth Cohort 1936 Study; Janie Corley et al.; Dec. 2009
- CNN.com: Coffee: Is it Healthier Than You Think?
- Johns Hopkins Bayview Medical Center: Information About Caffeine Dependence
- MayoClinic.com: Caffeine: How Much is Too Much?
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