Is It True That Caffeine Cause Dehydration? Learn What Research Has to Say about Caffeine and Dehydration

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Beverages such as coffee, tea, and soft-drinks contain caffeine in moderate or high proportions. One of most the favorite caffeinated beverages, no doubt, is coffee. Without it, we cannot kick-start our daily schedule.

It has been estimated that about 75 percent of Americans consume coffee daily. Research has revealed that caffeinated drinks, like coffee, enhance alertness and mental functions. But, the biological effects of caffeine are always surrounded by questions and controversies. In spite of the positive results, the negative effects of caffeine have sparked frequent debates. One of the most widely discussed subjects is that caffeine contributes to dehydration. Most experts are of the opinion that consuming caffeinated drinks leads to dehydration. So, does caffeine cause dehydration? Does consuming caffeinated beverages results in negative effects on exercise performances.

For a long time, caffeine has been considered as a diuretic. In simple terms, caffeine causes diuresis. Diuresis is a medical term meaning increased discharge of urine by the kidneys. Most people think that drinking caffeinated beverages can cause the body to lose more fluid, thus contributing to dehydration. For regular exercisers, caffeine is said to be the main cause of dehydration and abdominal cramps. So the million dollar question is: does caffeine cause dehydration?

What Does Research Say?

The common belief about caffeine’s potent diuretic effects is not supported by research. Most studies have found that caffeine has mild diuretic effects similar to water. In June 2002, a report appeared in the International Journal of Sport Nutrition and Exercise metabolism. The report included vital investigations about caffeine’s diuretic effect. It was conducted by Lawrence E. Armstrong, a well-respected scientist in the field of human performance and thermoregulation. According to Armstrong’s investigations, consuming caffeine had the following results:

• When an individual consumes moderate amounts of caffeine, the body retains some of the fluids

• Regular consumption of caffeine can lead to a higher tolerance to the diuretic effect

• Consuming moderate amounts of caffeinated beverages causes mild diuresis, much similar to water.

• The research concludes there is no evidence of the negative effects of caffeine to exercise performance.

Another study, published in the same journal, in 2005 revealed that caffeine does not cause dehydration. The study involved 59 subjects who were given caffeine in the form of capsule for some days. The subjects were also given a placebo for a few days. Researchers did not find any significant changes in the levels of urine volumes.

So far, research does not confirm about any connections between caffeine and dehydration. It says that caffeine is a mild diuretic and does not have any adverse effect on exercise performance.


The information in this article should not be considered medical advice. The information in this article is not meant to treat, diagnose, prescribe or cure any ailment. Always check with your physician before taking any products or following any advice you have read on Always consult your doctor before you start, stop or change anything that has been previously prescribed.


“The Claim: Caffeine Causes Dehydration”