Water: more than a thirst quencher.

If you were asked What plays one of the most important roles in maintaining good health? water may not come to mind, yet next to oxygen it is the most essential element for maintaining life. A healthy person can live for weeks without food, but can live only a few days without water. Take away the water content of our body, and we would shrink to a mere shadow of ourselves.

Our water intake should be sufficient to replace what is lost by normal body functions. An average-sized adult will eliminate from two to five pints of water a day through urine and the bowels, and about one and a half pints through perspiration and breathing. And an increase in exercise or hot weather could show a corresponding increase in water loss.

What makes us thirsty?

When the blood becomes too salty, water is withdrawn from our salivary glands into the blood and the mouth becomes dry causing us to drink. Also, the brain monitors the salt concentration of the blood. When it finds it too high, it sends out signals to stimulate drinking behavior. Much more must be learned about what governs the thirst mechanism.

Water in our body. The use of water in the body is quite unique. It acts as a lubricant around joints and protects sensitive tissue such as the spinal cord from shock.

The fluid that fills the eye helps keep optimal pressure on the retina and lens. The unborn baby is cushioned against blows by amniotic fluid as it develops within the mother's womb. Water also lubricates the digestive tract and all tissues moistened with mucus, and aids evacuation. It is considered very nearly a universal solvent, as it dissolves amino acids, glucose, minerals, and other substances needed by the cells.

Not only is water important during normal activity, but experts agree it is essential to maintain water balance during any exercise program. The more conditioned the body, the more water the tissues hold. A lack of sufficient water intake leads to dehydration, which causes a feeling of fatigue and impairs physical activity.

When exercising, plain water is the best drink. Stay away from carbonated drinks, which cause bloating. Coffee, tea, and cocoa are dehydrating, as are cola drinks, and such drinks often contain too much sugar, which actually increases our water needs. Even fruit juices have sugar--orange juice contains 10,percent. Unsweetened juices are preferable to fruit drinks and punches.

Water balance is also extremely important during illness. "No matter how healthy you may be, there might come a time when you are faced with a situation where you experience large losses of fluids during an illness," says Dr. Douglas Davidson, an internist in San Diego, California. Think of your body as a recycling plant that uses the same fluids again and again during each stop along the way via saliva and gastric, bile, intestinal, and pancreatic juices. Dr. Davidson states, "The amount of digestive secretions put forth in the average adult has been estimated at more than three times as much as the water taken in with food and drink and produced during metabolism. It is obvious that replacement of this fluid is of prime importance if vomiting or diarrhea occurs."

Patients suffering from high or prolonged fevers also have a steady loss of water that must be replaced to keep the chemical balance of the body fluid intact. They should be encouraged to drink water or other fluids at frequent intervals if they are able.

Children, the elderly, nursing moms.

Pediatricians caution parents that children at times do not drink enough fluids. Because they are so active, the loss of water through respiration and perspiration is relatively high. Children don't always realize that they are thirsty and should be checked and offered fluids frequently to ensure they. receive an adequate supply. High on the list of p, referred liquids are water and unsweetened fruit juices. However, if children drink too much before or during a meal, they may feel too full and have no appetite for needed food.

The elderly also need to be reminded to drink water. They should drink six to eight glasses a day, because a lack of fluids may lead to impaired kidney functions, constipation, fatigue, apathy, and even confusion.

Pregnant women are told by their obstetricians that they need an adequate supply of water and other fluids, but nursing mothers too must make certain their fluid intake is liberal to ensure an adequate supply of breast milk--a busy new mother may forget this. Since water is the major ingredient of breast milk, a mother's fluid intake is very important.

Air travel. Dry air combined with rapid air circulation in airline cabin ventilation can cause large water losses through the pores and breathing, contributing to let lag. It is important to compensate for this loss by increasing water intake before, during, and immediately after the flight. Drinking alcohol while flying increases dehydration, so stick to plain water or unsweetened fruit juices to replace fluid loss.

Water plays a most important role in our lives. It regulates body temperature, transports nutrients and wastes, and aids digestion and other metabolic functions. Without adequate amounts of water, our body processes slow down; we become tired and fatigued, and can become ill. With enough water, we feel more fit, and more energetic; our outlook on life seems brighter; our skin, hair, and eyes radiate a healthier look. Water is much more than a thirst quencher.

Joan Haider, a registered nurse who specializes in nutrition, is the mother of five children, and a published writer. She lives in San Diego, California.