Water is tasteless, odorless, and colorless to the senses but the most important nutrient for the human body. It may be transparent but it is vital to the existence of human beings. Water makes up about 70% of our body’s mass but can vary depending upon the size of an individual. Water is involved in every bodily function whether it is used as a solvent, made as a byproduct, or essential to the metabolic process. Water is constantly being expelled from the body through urination, respiration, sweating and digestion therefore it is essential to replenish the water in our body daily. It is recommended to ingest 2 liters of water per day through food, beverages and metabolism to avoid dehydration. However the old adage of drinking 8 glasses of water per day has no scientific basis. The amount of water that any one person needs to intake is dependant upon their levels of activity, temperature, humidity and digestion. Therefore anywhere from 1-7 liters of water maybe needed to be replenished upon a daily basis.
It is almost impossible to mistake the importance and necessity for water, due to its frequency in every cell, tissue, process and function within the body. Water is critical for maintaining body temperature, growth, lubricating the skin, mouth, nose and eyes, cushioning the joints, organs and spinal cord, transporting nutrients throughout the body, flushing toxins out of the body, digesting food and metabolizing fat. In addition water contains some trace elements that are critical to health such as calcium, zinc, manganese, phosphates, fluoride, sodium, potassium and chloride. Too much salt or sodium can actually decrease your water retention. Without water to properly preserve all of the body’s functions we would surely die. The body cannot survive more than a few days without replenishing its water supply.
Water is fundamental in the all the metabolic processes throughout the body. During metabolism water plays important roles in both anabolic and catabolic reactions. Throughout anabolic reactions water is removed from molecules to grow larger molecules such as starch, triglycerides and protein for storage of fuels and information. In catabolic reactions water breaks down bonds to make smaller molecules of glucose, fatty acids, and amino acids to be used as fuel for energy. In the course of respiration, water combines with carbon dioxide to form oxygen, which is used for breathing. Water is also central to the acid, base neutrality within the body. The body cannot be too acidic or basic which can cause disease. Water is naturally neutral. When a base neutralizes an acid, they form water. Blood is 90% water so that it can transport nutrients and energy throughout the body. It acts as a solvent for solutes to dissolve in to be moved to other cells, organs or muscles. Water also can remove waste from tissue by transporting them to the liver and kidneys to be excreted in the urine or feces. Water naturally suppresses appetite, stores additional energy and metabolizes fat to be used as energy rather than storage. Therefore dehydration or loss of water can actually impede weight loss. When the body is dehydrated the kidneys malfunction causing the liver to work harder. The liver normally metabolizes fat to make energy, but when taxed because of dehydration the liver metabolizes less glycogen and stores it as fat.
The effects of dehydration can be severe and are readily recognized both as physical and psychological symptoms. When the body becomes dehydrated it must pull water from other areas of the body including cells, blood, fat and tissue. This causes an immediate drop in blood pressure, small capillaries and blood vessels close, the blood begins to clot, the kidneys malfunction which causes the liver to work overtime to compensate, and the heart has to work harder to pump thicker blood throughout the body. Physical symptoms are felt as constipation, headaches, fatigue, weakness, muscle cramps, and dry mouth. Physical performance is highly affected by dehydration. Prolonged dehydration can lead to heart disease, high cholesterol, hypertension, arthritis, heartburn and ultimately death.
Proper hydration throughout the day is vitally necessary. Drinking appropriate amounts of water after exercise, physical activity, in hot weather are essential to maintaining proper body function. It is important to understand that too much water or water intoxication (hyperhydration) can also be fatal. Although the opposite, dehydration is more likely to occur understanding that it is possible should be known. Most people can tell when they haven’t had a enough water and stop drinking when they are no longer thirsty. Thirst, hunger, dry skin, nails, hair and mouth are the immediate signs of the need for hydration. The best resource is to always carry a bottle of water with you wherever you go.
Sarah Labdar, “Why is Water so Important?”, Everyday Health