The truth is out there. Coffee and tea drinkers generally adhere to the belief that caffeine causes dehydration due to its property as a mild diuretic. Sophie C. Killer is the lead author of the latest study on the subject by a team of researchers at the U.K. University of Birmingham School of Sport and Exercise. An online science publication, PLOS ONE published Killer’s study that concluded that a moderate amount of coffee does not cause dehydration. Instead, the study confirmed that coffee contributes towards the recommended daily fluid intake, as do other liquids.
The objective of this study was to measure the effects of moderate coffee consumption compared to equal volumes of water. Fifty male participants were required to drink 200ml or the equivalent of four mugs of black coffee or water per day for three days. After a “wash out” period of a span of ten days, their drink was switch while maintaining the same amount. The men’s body mass and total body water, blood and urine measures did not show significant hydration differences. There were also no differences in 24-hour urine volume or concentration presented between the two groups.
What happens when we are dehydrated? As the word suggests, dehydration occurs when our bodies are taking in less fluids than they are expending. During especially hot weather, illness or intense exercise, just to name a few, we should ensure that we replenish with fluids. Infants, small children, elderly adults and individuals with chronic health issues are especially at risk of dehydration.
Other causes of dehydration are severe diarrhea, vomiting, fever, excessive sweating, or increased urination. Sometimes, a change in our normal routines such as traveling, hiking, or camping can cause dehydration as well. When we are sick or busy, keeping well hydrated is usually one of the first habits we fall out of routine.
Mild to severe symptoms of dehydration include light-headedness, dry skin, fatigue, fever, rapid heartbeat, thirst, headaches, low blood pressure or even unconsciousness. Serious complications can arise from dehydration such as swelling of the brain, seizures, kidney failure, coma and even death. Severe dehydration can be fatal.
When temperatures get hot and humid, fluid intake should increase. Quick rehydrating methods include drinking water or sports drinks. Children can be encouraged to rehydrate with popsicles or over the counter oral rehydration solutions. All emergency preparedness kits should include appropriate amounts of water or fluids for as long as 72 hours. A regular habit of drinking plenty of fluids can keep us healthy, and at least for the time being, that includes coffee.
Although there was little to no evidence that linked caffeine, or coffee, as a cause of dehydration, the myth continues to be widely believed. Two earlier studies looked into the hydration effects of coffee in 1997 and 2000. Their investigations produced mixed results. Killer and her team wanted to show conclusively if regular coffee drinkers were at risk of dehydration as was widely accepted. The Institute for Scientific Information on Coffee (ISIC) provided the funding for this latest research. ISIC is a non-profit organization that is devoted to the scientific study of coffee and health, which also publishes a science-based resource, a website at http://www.coffeeandhealth.org, for the latest information and research concerning coffee, caffeine and their impact on health.
Science now supports our love affair with that dark, sweet smelling brew at least up to the fourth cup. As mentioned at the beginning, the truth is indeed out there, and this time, the truth has set us free. Cheers and bring on the coffee!