Water: Effects Of Hydration On The Human Body

Effects of Hydration on the Human Body
Rebecca St. Clair
SCI/241
January 9, 2011
Ms. Katherine Jones, Ph D

Water is an essential nutrient that provides health maintenance by regulating body temperature, providing lubrication and shock absorption, and is essential to maintain proper physiologic functioning. Over half of the human body weight is comprised of water. Water helps to regulate many human body functions such as: body temperature, and the amount of water lost through kidney functions. Electrolytes are tri-fold and are comprised of Sodium, Potassium, and Chloride. Electrolytes assist with balancing body fluids. Dehydration can be life-threatening, and occurs when water loss exceeds water intake, and ultimately results in
a negative balance. “Body temperature is the level of heat manufactured by the body”. Body heat is primarily created through the metabolic break down of food. Heat is lost from the body through the following processes: evaporation of sweat, convection, and radiation. When heat is lost through the body in the form of sweating the body is actually being cooled, and an individual may have a rosy look on their face as blood flows close to the surface of the skin. Water is also expelled from the body through our lungs and skin. The term used to describe the loss of water through the body is Thermoregulation. Thermoregulation can be studied in great detail through varied environmental settings and through extreme physical demands such as marathon running. Runners need to be keenly aware of the impact of proper fluid balance. Low body fluid levels can compromise heat loss (sweating) through exercise, and can increase thermal strain. Early indications of dehydration can include: nausea, vomiting, and headache. Water is also a solvent. Substances needed by the body are dissolved with the assistance of water. These substances include: amino acides, glucose, and minerals. Water helps to keep acidity levels at the proper percentages. Kidneys play a major role in regulating water loss through the body. Most water is excreted from the body through urine. The kidneys help to regulate the amount of water loss that actually occurs. Typically, kidneys will produce 1 to 2 liters per day however the amount can vary based off of fluid consumption and the amount of other waste products that need to be excreted. Kidneys play an even more important role in that they produce a hormone called anti-diuretic hormone. This hormone signals the kidneys to re-absorb water when water levels are low. The water is re-absorbed into the body, thus reducing the amount of water lost in urine. Water is essential to the body for adequate health maintenance.
Water moves freely throughout the body in conjunction with electrolytes. The diffusion of water throughout cells within the body is called osmosis. Osmosis is relied upon to keep the level of water in the body’s’ compartments at the proper levels. The proper balance of water and electrolytes is essential for optimal physiologic functioning. Among the many roles water plays it also acts as a building material, a carrier for waste and nutrients in thermoregulation among other functions. Water is the one primary nutrient that is extremely essential for body hydration, it is a fact that the human body can only survive about 3 days without water – the body can last a lot longer without food than the essential nutrient –
water. Body fluids are broken down into two “compartments” within the body: (ICF) Intracellular and (ECF) Extracellular. The sum of fluid within all compartments of the body, including ICF and ECF is known as total body water (TBW). With the onset of dehydration, essential electrolytes become imbalanced particularly sodium, potassium, and chloride. Alcohol inhibits the activity of ADH which increases water loss. Typically, if an individual is over-hydrated before consuming alcohol, there will only be a slight increase in diuretic effects on the body. If an individual is under-hydrated before consuming alcohol, then there is an increased chance for the feeling of a ‘hangover’ which can include headache, and nausea. Caffeine tends to have the opposite effect. Caffeine can cause dehydration, particularly after a workout. Research has proven that hydration levels are only affected typically after workouts. Caffeine is a stimulant, which means it speeds up the nervous system and can provide the body with energy. The other effect that caffeine can have on the body is that it can be addictive, you can become dependent upon it to feel energized throughout the day, and one can also experience withdrawal symptoms from caffeine. Dehydration poses a significant problem for older adults and is the most common fluid and electrolyte problem in both long-term and at-risk community-dwelling elderly (Burke & Earamie, 2000; Weinberg et al., 1995). Some early signs of water deprivation include: thirst, impaired swallowing, and decreased production of saliva. With increased scientific study, there is a growing body of evidence that implies that an individuals’ good days is largely impacted by ones’ personal state of hydration. The daily average of water lost through normal body functions is 2.5 liters. The human body is 60% water weight that means a person who weighs 180lbs is approximately 108lb of water; this is a large amount of water.
This should be a reminder of the importance of replenishing the body constantly with water. Dehydration occurs when more fluid is expelled than is taken in. One of the first preventative measures an average adult can take to protect against dehydration is to drink more water. The average sedentary adult should drink at least 1.5 liters per day. Water simply is the only liquid nutrient that is essential for body hydration. The body will signal the need for water when we feel “thirsty”. Mouth dryness will occur – this is due to less saliva present due to low levels of water. Although thirst is a powerful urge this cannot be relied upon solely to maintain a healthy level of water in ones’ body. The sure way to maintain water levels is to consistently consume water – preferably on a daily basis. Although the need to use the lavatory increases significantly with increased amounts of water consumption, this small annoyance is a small fee to pay for the long-lasting benefits of proper hydration.

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