Water and Our Body

Water is so important and basic to life that without it, we simply would not exist.

Water is the main constituent of the human body. In order to survive, each of us must consume a certain amount of water on a daily basis. Water is essential because it is in every cell, tissue and organ in our body. For the body to function properly, an adult male needs about 3 liters (12 cups) per day of water and an adult female needs about 2.2 liters (8 cups) per day.

We need water to replace what the body loses through normal everyday functions. Water is lost when we go to the bathroom or sweat, but we even lose small amounts of water when we exhale. All this lost water needs to be replaced for good health, to sustain the body’s many vital chemical reactions, to prevent dehydration and for the body to operate correctly. No other nutrient is more essential in such large amounts than water.

Water makes up a large part of the body:

  • Men - 60% water
  • Women - 55% water
  • Eyes - 95% water
  • Muscles and heart - 75% water
  • Brain - 90%
  • Blood and kidneys - 81% water
  • Liver - 71% water
  • Bones - 22% water
  • Lungs - 83% water
  • Skin - 64% water

Water serves a number of essential functions:

  • Carries vital nutrients and oxygen to every cell
  • Moistens tissues for mouth, eyes and nose
  • Regulates internal body temperature 
  • Lubricates and cushions muscles and joints
  • Acts as a shock absorber inside the eyes and for the spinal cord as well as other sensitive tissues
  • Reduces the burden on kidneys by flushing and eliminating wastes like uric acid, urea and lactic acid through urination
  • Plays an important role in the digestion of food and the absorption of nutrients from the digestive tract and helps prevent constipation
  • Carries waste products and toxins from the body
  • Important for proper functioning of the brain
  • The correct regulation of water is essential to keep blood pressure within the healthy range

The European Hydration Institute (FEHI); www.europeanhydrationinstitute.org 
U.S. Geological Survey, Department of the Interior; www.USGS.gov
Center for Disease Control; www.cdc.gov

Winter 2014

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