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True or False: Caffeine is dehydrating

True or False: Caffeine is dehydrating

By Carolyn Hauck on February 03, 2015

As unbelievable as it may seem, there is a small percentage of people who don’t drink caffeine on a regular basis, but it’s likely that you’re one of the majority that enjoys coffee or soda daily. It’s also likely that you’ve heard that those caffeinated beverages you love are dehydrating.

Caffeine is indeed a mild diuretic (causes urination), so it contributes to water loss in your body. However, a study done nearly 15 years ago by Dr. Ann Grandjean and her colleagues called the link between caffeine and dehydration into question. They found that there was little to no correlation between daily caffeine intake and dehydration as long as the caffeine stayed at average levels—less than 500 milligrams a day or roughly two cups of strong coffee. Soda has far less caffeine—averaging around 70 mg a can and 45 mg a can per diet soda, however the bad health effects of soda outweigh the caffeine issue. Therefore the Food and Drug Administration recommends no more than one can of soda a day.

Studies have also recognized that coffee and soda actually contribute to your daily fluid intake, so it’s a wonder that the dehydration myth has persisted for so long. But that might be because there are other health risks involved with caffeinated beverages.

For one, if you do happen to drink more than two cups of strong coffee a day, you could actually be slightly dehydrating yourself, especially if you are drinking coffee in place of water.

As mentioned before, the health risks associated with soda far outweigh the issue of caffeine. The sugar in soda provides a greater health risk than caffeine, as does the aspartame and sodium in diet and decaffeinated sodas. These health risks include high cholesterol, high blood pressure, headaches and diabetes.

Staying hydrated

Not unsurprisingly, Dr. German on JustAnswer recommends sticking to water when you’re thirsty and enjoying soda only occasionally.

You can also safely turn that “8 glasses of water a day” recommendation by the Institute of Medicine into “8 glasses of fluid a day” (which includes coffee, tea, juice, etc.) to keep your body at healthy hydration levels.

Final verdict? FALSE. Caffeinated beverages are not dehydrating.

Concerned about your own hydration issues? Doctors on JustAnswer can address your questions now.