Water is a vitally important component of any valuable and useful nutrition plan. This statement is hardly earth shattering or groundbreaking and few (if any) jaws will drop at the sight of it. It is common knowledge that water is essential to our survival as living beings. Most people are very well aware of this fact, but do they really know why water is so essential? What does water do in our bodies and why does it make a difference what kind of water we drink? Is a water filter truly necessary and worth its price? Read on to learn the answers to these questions and find out how much you know (or don't know) about that magical, life-giving fluid: water.

Some Water Basics
Depending upon whom you ask, water makes up anywhere from 60% to 90% of our body's matter. Not only is water essential for ensuring our survival as human beings, it is also essential for the survival of the earth and all living organisms on it. In its simplest, most pure form, water is a molecular compound composed of two hydrogen atoms and one oxygen atom. Although water contains no calories, it is absolutely essential for maintaining energy levels, regulating body temperature, controlling cravings, and cushioning sensitive organs, tissues, and joints within the body. Water is the substance that ensures that our bodies continue to run; water also ensures that they run efficiently.

Once water enters the body, it quickly travels through the esophagus into the stomach where it is digested and sent to the appropriate locations within the body. Water then becomes the major constituent of blood, ensuring the transfer of all other nutrients to the organs and tissues of the body. After all organs and tissues have received their needed amount of water and accompanying nutrients in order to ensure proper cell functioning, the body then sends excess water to aid in the transfer of wastes out of the body through the kidneys, bladder, and rectum. In essence, water is the major means of transport for all substances in and out of the body.

It is necessary to continuously replace water in the body as such a large amount of water is expelled from the body each day through simple respiration. While a person may live for four weeks or more without food, he or she will only live for approximately one week without water. The exact amount of water one needs to drink each day to replace water in the body depends upon a number of factors and cannot easily be calculated. However, most nutritionists agree that eight glasses (two liters) of water each day is an appropriate amount for most people. This number may change when a person's level of physical activity and environmental climate are taken into consideration.

Benefits of Drinking Enough Water
Besides the maintenance of normal bodily functions and the regulation of body temperature and general energy levels, drinking adequate amounts of water can result in some significant health and cosmetic benefits. First of all, water has long been known and recognized as a valuable diet aid. Many cravings for food are often misdirected cravings for water. Once the body is satiated with the needed drinking water, cravings are greatly reduced. Water also ensures a general level of health and fitness by quickly transferring toxins and other harmful substances out of the body. Water naturally moisturizes the skin and hair, as well, giving them a healthy, glowing appearance. Water can also serve as a natural protection against several types of cancer.

When a person becomes dehydrated (meaning he does not have adequate amounts of water in his system to ensure proper body functioning), the symptoms of dehydration quickly appear. These symptoms include, but are not limited to: fatigue, headaches, difficulty concentrating, and constipation.

How Important is Clean Drinking Water?
Water is something of an interesting substance. It is a natural solvent; therefore, wherever water travels, it dissolves and carries along other substances. For this reason, there really is no "pure" water available in the world. Water always carries other substances, whether these substances are useful minerals or dangerous chemicals and biological contaminants. One would be absolutely amazed at the amount of contaminants a simple water filter removes from "treated" tap water.

While the natural solvency of water is one of its most valuable characteristics (due to the usefulness of this characteristic in allowing water to carry and dissolve food nutrients for use in the body), it can also be one of its most volatile and dangerous characteristics. It is certainly vital to maintain an adequate amount of water in the body, but to be truly beneficial and effective, that water needs to be as clean and pure as possible. When water carries such contaminants as chlorine or lead into our bodies, it can actually become more harmful than beneficial. Water, laced with such contaminants, can become a cancer-causing agent or a purveyor of brain damage and learning disabilities.

We cannot simply cut water out of our diet, despite its penchant for carrying contaminants with it; water is far too essential to our survival. Thus, it becomes our responsibility as wise and conscientious individuals to clean that water and know what it contains before we take it into our bodies. We will likely never receive pure, clean water directly from the tap, but a home water filter can remove several of the most dangerous contaminants from that water before we drink it. A water filter can help to ensure that we receive all of the benefits of drinking adequate amounts of water and none of the adverse health consequences of drinking contaminated water.

Vanessa Lausch is a technical writer for http://www.allaboutwater.org/, an online guide to drinking water.