The human body can last weeks without food, but only days without water. The body is made up of approximately 55% to 75% water. Water forms the basis of blood, digestive juices, urine, and perspiration and is contained in lean muscle, fat, and bones.
As the body can’t store water, we need fresh supplies every day to make up for losses from lungs, skin, urine, and feces. Water is needed to maintain the health and integrity of every cell in the body, keep the bloodstream liquid enough to flow through blood vessels, eliminate the byproducts of the body’s metabolism, flush out toxins, regulate body temperature through sweat, lubricate and cushion joints, and carry nutrients and oxygen to the body’s cells (just to name a few). Drinking clean water plays a major role in reducing the risk of certain diseases.
The loss of water through urination is greatly increased by the ingestion of decaffeinated and alcoholic beverages. These drinks have a diuretic effect, meaning they stimulate the kidneys to excrete more urine. Not only do we lose water, we also lose water-soluble vitamins, such as vitamin C, vitamin B (thiamine) and other B complex vitamins. For every caffeinated or alcoholic beverage you drink, you need to add an additional glass of purified water.
A diet containing lots of fruits and vegetables will supply about four cups of water per day. Even with a diet high in fruits and vegetables, it’s still necessary to drink an additional six to eight cups of water per day to supply enough to meet the body’s daily needs.
Dehydration occurs when the body’s water content is too low. This is easily fixed by increasing fluid intake. Symptoms of dehydration include headaches, lethargy, mood changes, slow responses, dry nasal passages, dry or cracked lips, dark-colored urine, weakness, fatigue, confusion, and hallucinations. Eventually urination stops, the kidneys fail, and the body loses its ability to remove toxic waste products. In these extreme cases, dehydration can result in death.
Approximately six to eight glasses of a variety of fluids should be consumed each day. More than eight glasses may be necessary for people who are more physically active, children, people who live in hot or humid environments, and breastfeeding women. Less water may be needed for sedentary people, older people, people who live in cold environments, or people who consume a lot of high water content foods.