Four-hundred-million cups of coffee are consumed in America daily. Caffeine is a stimulant that many people drink to increase alertness. Caffeine increases the functioning of many of your systems, including the central nervous system, suggesting that caffeine increases alertness. However, recent evidence suggests caffeine does not increase alertness, due to a tolerance buildup to caffeine's effects.
Caffeine Boosts Alertness
Moderate caffeine consumption has been connected with an increase in alertness, according to a study presented to the American Chemical Society in 1999 and conducted by Astrid Nehlig, Ph.D., of the French National Health and Medical Research Institute. This study was aimed at linking caffeine with dependence, but also found that those who consume caffeine are more alert. The mechanism is simple. Caffeine is a stimulant that acts on many systems of the body, including the nervous system. By stimulating the action of the nervous system, caffeine is though to increase your alertness.
Caffeine Does Not Boost Alertness
According to a recent study published in the June 2010 issue of "Neuropsychopharmacology," caffeine does not cause alertness. This study took 379 individuals; half were no or low coffee consumers and the other half were moderate or high coffee consumers. After 16 hours of abstaining from caffeine, individuals were given either coffee or a placebo, then rated their mood and physical feelings which were followed up by alertness and cognitive tests. There were no differences in alertness varying from those who drank coffee versus those who received the placebo.
A Caffeine Tolerance
Researchers involved in the study published in "Neuropsychopharmacology" in June 2010 state that those who drink coffee regularly may have a developed tolerance to its effects. The alertness regular coffee drinkers feel after having their regular amount, simply brings them back to their "normal" state. In addition, researchers state that caffeine can increase your anxiety levels, which may be part of the effect that caffeine has on your cognitive state.
Consumption
Caffeine affects many parts of your body, including your cardiovascular, digestive and urinary systems. If caffeine is not really making you more alert, you may want to consider cutting back to prevent any negative health effects. However, Sheldon G. Sheps of MayoClinic.com does report that low to moderate consumption of caffeine should be safe. Taking in 200 mg of caffeine per day, about two cups of coffee, should be okay if you just can't live without it.
References
- ScienceDaily.com; Debate Brews Over Caffeine Addiction -- Study Also Confirms Caffeine Improves Alertness And Energy; 1999
- Washington University: Caffeine
- MedicalNewsToday; Caffeine Doesn't Make You More Alert; 2010
- DailyMail; Coffee Does NOT Wake You Up. It's All In Your Mind; Jenny Hope; 2010
- MayoClinic.com; Caffeine: How Does It Affect Blood Pressure?; Sheldon G. Sheps, M.D.; 2009
- Gourmet Coffee Zone: Coffee Facts
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