Caffeine is the only drug prevalent in widely consumed foods, according to the Center for Science in the Public Interest. The bitter-tasting substance occurs naturally in cocoa, tea and coffee plants, and is added to numerous soft drinks, energy drinks and dietary supplements geared toward boosted energy, metabolism or wakefulness. Depending on how much you consume, caffeine may have a negative impact on hydration. Learning more regarding this potential risk may inspire you to make wise dietary decisions.
Theories
Dehydration happens when, as a result of losing more fluid than you consume, your body lacks enough water and other fluids to function normally. Researchers once believed that caffeinated beverages have a diuretic, or fluid-flushing, effect, according to MayoClinic.com dietitian Katherine Zeratsky. If this were true, drinking any amount of coffee, caffeinated soda or tea would cause you to release more urine, increasing your risk for dehydration. Although some people continue to view caffeine as a diuretic, fluid loss is unlikely unless you consume excessive amounts of caffeine.
Potential Risks
Consuming more than 500 to 600 mg of caffeine, the amount found in four to seven cups of coffee, may have a diuretic effect, according to Zeratsky. Mild dehydration symptoms may include thirst, dry mouth, sleepiness, dry skin, headache, constipation, low moods and lightheadedness. Serious dehydration can cause extreme thirst, sleepiness and dry mouth, lack of perspiration, sunken eyes, little or no urination, shriveled skin, fever, heart and breathing problems and, in the most severe cases, unconsciousness.
Research
In a report published in "Nutrition Bulletin" in March 2008, researchers reviewed 41 human studies on the potential risks and benefits of caffeine. Most of the studies showed a positive link between heightened alertness, moods and perception of fatigue and moderate caffeine intake, or 37.5 to 450 mg per day. Moderate caffeine intake was not associated with dehydration, even among athletes undergoing exercise testing. Excessive caffeine intake, on the other hand, was linked with anxiety, sleep problems and headache.
Considerations
Water is your "best bet" for staying hydrated, according to Zeratsky. Fresh fruits and vegetables, broth-based soups, juices and low-fat milk also promote hydration. If you enjoy caffeinated foods or beverages, aim for moderate intake, keeping in mind that intense exercise and spending time in hot weather increase your hydration needs and that energy drinks may contain additional stimulants, such as ginseng, tea extract or guarana. To avoid potential health complications, discuss caffeine use with your doctor, particularly if you are pregnant or have illnesses, such as heart disease.
References
- Center for Science in the Public Interest: Caffeine Content of Food & Drugs
- MayoClinic.com: Dehydration
- MayoClinic.com: Caffeine: Is it a Diuretic?
- MayoClinic.com: Dehydration Symptoms
- "Nutrition Bulletin"; The Impact of Caffeine on Mood, Cognitive Function, Performance and Hydration: a Review of Benefits and Risks; C. H. S. Ruxton; March 2008
- University of Maryland Medical Center: Caffeine in the Diet
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