More than a refreshing beverage or a place for fish to swim, water is essential for life. Approximately 60 percent of your body is water, according to the Mayo Clinic. Jessica Hamzelou writes in "New Scientist" that the length of time humans can survive without water varies according to how much water they're losing through respiration and sweat, but that even in a cool climate humans can't survive more than a week without water.
Nutrients
Water delivers nutrients to the body. When you eat, digestive enzymes in water dissolve the food. Essential nutrients that are dissolved in water pass through membranes in the intestines, then travel to cells. Your blood is 83 percent water, which allows it to flow freely through veins and arteries, carrying oxygen, iron and other vital nutrients to every part of the body.
Waste Disposal
Water in the form of blood, sweat, urine, tears and mucus carries waste away from the body. Water helps flush harmful toxins from your body, according to Mayo Clinic. Water keeps nasal passages moist, making the fine hairs inside your nose, called cilia, more effective at filtering out harmful or irritating substances.
Comfort
Water keeps the body working smoothly and makes you more comfortable. Water lubricates the eyeballs and keeps lips and skin moist. If you travel to a dry climate, you may notice dry, scratchy eyes, cracked lips and dry skin. Water allows for more comfortable bowel movements.
Temperature Regulation
Sweating and the evaporation of sweat help keep your body cooler in hot weather. Water also plays a role in keeping your body warm, as blood vessels dilate and blood rushes to vital organs and the brain and away from extremities when you're exposed to extreme cold.
Water Needs
You lose water every day through urination, sweating and respiration. The Mayo Clinic reports the average adult produces 1 1/2 liters (6.3 cups) of urine a day and loses an additional liter (about 4 cups) through respiration, sweating and bowel movements. You'll need to replace at least that 2.5 liters (just over 8 cups) of water each day to avoid dehydration; more if weather is very hot or very cold, or if you engage in strenuous activities or live in a dry climate. You get about 20 percent of your water needs from food. The rest can come from any liquid, though alcohol and caffeine have a dehydrating effect that offsets some of their intake.
Member Comments