Drink Up: How Much Water do We Really Need?

There has been a long debate about how much water the average person should drink on a daily basis. The old standard of “8x8,” or eight servings of eight ounce glasses of water each day, a mere 64 ounces, has been argued against. But why?

An article published in the British Medical Journal dismissed the commonly accepted 64 ounces as “nonsense,” and questioned if there were any health benefits of drinking this much water daily. According to the study’s author, Dr. Margaret McCartney, a general practitioner in the UK, there is no evidence to support anyone consuming 64 ounces of water. However, the European Food Safety Authority, (EFSA) has set guidelines recommending folks drink 2 liters a day for adult women, and 2.5 liters a day for adult men, under normal conditions of activity and temperature. The EFSA considered that solid foods will contribute approximately 20 percent of that amount, which is fairly standard. From a public health perspective, taking into account the growing obesity problems worldwide, water has a unique role to play in a healthy diet and therefore drinking water should be promoted, not discouraged.

The problem with the BMJ article was that it wasn’t peer-​reviewed (most medical journal articles are peer reviewed – that’s pretty standard) and Dr. McCartney’s article created headlines in the UK press suggesting that drinking water is bad for you. Hydration is fundamentally important for the elderly and the very young, and it’s better to obtain a majority of your fluids from water, whether bottled or tap water, than from sugary sodas and caffeine-enriched sports drinks. The British Nutrition Foundation suggests 6 to 8 glasses of water daily. The National Patient Safety Agency in the UK states on their website: “Improving hydration can help to reduce the use of medication. It can also assist in the management of diabetes and help to prevent pressure ulcers, constipation, urinary infections, kidney stones, heart disease, low blood pressure and many other illnesses.”

Even in America there are general hydration guidelines. The U.S. Institute of Medicine set “general recommendations for women at approximately 2.7 liters (91 ounces) of total water from all beverages and foods each day, and men an average of approximately 3.7 liters.” The United States Department of Agriculture (USDA) states, “Choose water as your primary beverage. Water is also thirst quenching, contains no calories, fat, cholesterol, or caffeine, and is low in sodium.” And the USDA goes on to proclaim many other benefits of water: it helps regulate body temperature, carries nutrients and oxygen to the cells, provides moisture to skin and other tissues, and water helps strengthen muscles. The USDA suggests a healthy adult needs 8 to12 cups of water to, “replace the amount lost through perspiration, breathing, urination, and bowel movements. These fluids must be replaced to avoid dehydration and to keep the body working normally.” The Mayo Clinic agrees stating on its website, “In general, doctors recommend 8 or 9 cups,” of water daily. Clearly these reputable organizations disagree with Dr. McCartney. Therefore, I wonder what exactly her point was?

As a follow-up on her website after a berating in the press, Dr. McCartney wrote, “Of course I would recommend water over sugary drinks, absolutely. The only thing I am trying to say is that we do not need to drink more than we would normally do. The bottled water industry is pushing the idea that we should drink more than we normally would with the promise of health benefits, and I don’t think there are any.” I disagree; water has been shown conclusively to ail a multitude of health problems. What’s troubling is that she wages war on water, not caffeinated drinks, not sodas with their sugar and unhealthy additives, not sports drinks or alcohol, but water. Does the bottled water industry have a vested interest in people drinking more water? Of course they do, but no one is forcing anyone to buy bottled water. Hydration comes from water, whether bottled or tap and we need water, daily. And consider this: You can live without food for days, even weeks. But more than three days without water and you will suffer severe dehydration and within 5 to 7 days you’ll probably be dead. Seriously.

That a general practitioner doctor in the EU can raise a stink about the most beneficial liquid on the planet seems like grandstanding and she certainly got the attention she was looking for - more hits on her website, and she probably secured additional articles for other publications. None of that diminishes the fact that water is nature’s best healer. I constantly promote that people drink more water and support the idea of drinking at least 2 liters each and every day. Most important, always listen to your body; if it is thirsty, reach for water.