Water Is Vitality

Water Is Vitality

May 27, 2024

Joy Stepinski, MSN, RN-BC

You may know water is vital to life. Can you explain how? Consider a houseplant. When neglecting to water the soil, the dirt holding the plant’s roots becomes parched. The leaves turn yellow and brown. Eventually, the plant, which was once initially full of green color and vibrance, will die.  Similarly, water is necessary for humans to survive and thrive. Water comprises 60% of the human body [1]. This percentage is frequently higher among infants and children, due to the extracellular water distribution in that age group. Water is a major component of physiological processes, with profound implications when an insufficient amount is taken.

What is the role of water within the human body? First, consider the fascinating and unique properties of the water molecule. Water consists of oxygen and hydrogen. The hydrogen atom contains a positive charge that allows it to bond with the negative charge of an oxygen atom on a separate molecule. This creates an electrostatic attraction [2]. Among its properties is the ability to dissolve substances within the body, such as glucose, proteins, and vitamins. Other substances, such as lipids, cannot be dissolved. This is important because cell membranes, DNA, and additional substances form and maintain their structure because water’s cohesion property creates surface tension.

In this manner of dissolving substances, water provides circulation to deliver the required nutrients to their destination and remove waste. Cells receive nutrients from water, which comprises 92% of the plasma circulating in the body [3]. Plasma, red blood cells, white blood cells, and platelets are the main constituents of the blood supply. Water is the substance that allows for nutrient exchanges between the cells, the interstitial fluid surrounding the cells, and the capillaries [1]. To function properly, organs depend on adequate volume inside the blood vessels for proper perfusion. Water provides this volume.

Next, water is needed to regulate the body’s temperature. Water can maintain heat because it stores energy [2], which is important when exposed to various environmental temperatures. Sweating allows water to evaporate through the skin when the body needs to lose heat. In this way, water maintains a constant temperature for the internal environment.

Because water is a solvent, it helps to form other body fluids. Mucus is within the airways, digestive tract, and genitourinary tract, of which 95% is water [4]. The role of mucus is two-fold. Not only does mucus protect the airway and intestinal surfaces, but also binds to debris and bacteria. Synovial fluid lubricates joints, crucial to mobility. Saliva enables food to be digested by the digestive tract.

The structural role of water within the human body is evident in bone, cartilage, and muscle. Approximately 15 to 25% of bone tissue contains water, giving bone tensile strength, elasticity, toughness, and fracture protection [5]. Likewise, cartilage depends upon water. Eighty percent of the wet weight of articular cartilage is water, which contributes to joint mobility. This provides lubrication and enables nutrient distribution to chondrocytes that create cartilage. Because a high percentage (76%) of muscle mass holds water [2], a decrease in total body water correlates with loss of muscle mass and strength.

Water is necessary for the body’s elimination system to rid toxins and waste.  Although most water is eliminated through the kidneys, other processes involved are sweating, breathing, and feces. Kidneys filter the blood to eliminate waste through the urine [2]. Drinking sufficient water protects these organs. One cross-sectional study used a population of 4,633 adult participants from the 2011 – 2012 National Health and Nutrition Examination Survey (NHANES) strictly investigating water intake. Participants were divided into three groups: low daily water intake (<500 mL), moderate (≥500 to <1200 mL), and high (≥1200 mL). The study concluded that the prevalence of chronic kidney disease and albumin in the urine (a protein that normally helps maintain blood volume and transports various substances) was inversely correlated with water volume intake [6]. Inadequate hydration can also play a key role in constipation [7]. Sufficient water prevents stools from becoming too hard.

Not receiving enough water is detrimental to the body, which can occur within hours [8]. Symptoms can be quite profound. Signs of early dehydration include a dry mouth, headache, decreased urine output, thirst, muscle weakness, lack of tears, dizziness, and fatigue [1]. If lack of hydration persists, severe symptoms include irritability, confusion, fussiness in infants or children, scant amber-colored urine or no urination, shriveled and dry skin, sunken eyes, low blood pressure, fast heartbeat, fever, delirium, and unconsciousness.

Humans receive water through food, beverages, and metabolism. The body must maintain a balance between intake and elimination. The amount of water required can vary, due to climate, physical activity, diet, and metabolism [1]. Adequate daily water intake is estimated to be 3.7 L for young men (19 to 30 years old) and 2.7 L for women of the same age, of which 19% is acquired by food [8]. The majority of water intake (70 – 75%) is accounted for by drinking.  Studies suggest a sedentary adult should drink 1.5 liters of water every day [1]. Sixty-four ounces of plain water daily is optimal for adults, and half the weight in ounces for children. More may be required in hot weather or during exercise. Water brings vitality to survive and thrive. Drink up!

References

1. Jéquier, E., & Constant, F. (2010). Water as an essential nutrient: the physiological basis of hydration. European Journal of Clinical Nutrition, 64(2), 115-123.

2. Lorenzo, I., Serra-Prat, M., & Yébenes, J. C. (2019). The role of water homeostasis in muscle function and frailty: a review. Nutrients, 11(8), 1857.

3. American Red Cross. (2024). Blood components. https://www.redcrossblood.org/donate-blood/how-to-donate/types-of-blood-donations/blood-components.html

4. Hansson, G. C. (2019). Mucus and mucins in diseases of the intestinal and respiratory tracts. Journal of Internal Medicine, 285(5), 479-490.

5. Surowiec, R. K., Allen, M. R., & Wallace, J. M. (2022). Bone hydration: How we can evaluate it, what can it tell us, and is it an effective therapeutic target?. Bone Reports, 16, 101161.

6. Wang, H. W., & Jiang, M. Y. (2021). Higher volume of water intake is associated with lower risk of albuminuria and chronic kidney disease. Medicine, 100(20), e26009.

7. Diaz, S. Bittar, K., Hashmi, M. F., Mendez, M. D. (2023). Constipation. In StatPearls [Internet]. StatPearls Publishing.

8. Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Panel on Dietary Reference Intakes for Electrolytes, & Water. (2005). Dietary reference intakes for water, potassium, sodium, chloride, and sulfate. National Academies Press.