The Health Benefits of Water
By Atticus
July 2010
Water is the most abundant compound on Earth; its
little surprise that it’s also the most abundant compound in the human body – we’ve all heard the statistics,
nearly two-thirds of your body weight is water. It comprises three quarters of your muscles and brain, and
five-sixths of your brain. Even your bones contain water, nearly a quarter by weight.
All living forms require water for survival. A well-nourished adult may live for
weeks without food, yet deprived of water that same adult will perish in as little as seventy-two hours. Yet
according to the World Health Organization, over a billion people do not have easy access to clean, safe drinking
water. Not so in the U.S. -- though ironically, Americans spend an estimated $ 20,000 per minute on bottled water,
creating 2.5 million tons of plastic bottles each year.
Here’s a short list of the myriad ways in which our body uses water for life
processes; some are obvious, some not so, and there might even be one or two that surprise you.
* Human beings perspire to dissipate excess heat in order to lower our internal
temperature.
* Water in the form of blood is the medium for distributing oxygen throughout the
human body while collecting the carbon dioxide from all these parts by dissolving these gases.
* Through the circulatory and lymphatic systems, water carries nutrients and hormones
throughout the body and removes toxins, dead cells, and other waste material.
* Water is necessary for the dilution of minerals in order to make them transportable
through the body.
* The proteins and enzymes involved in metabolic processes require water for proper
functioning.
* The body regulates water to maintain a slightly-alkaline pH range of 7.35-7.45, the
range at which it functions best. The body’s natural alkalinity is conducive to oxygen uptake and immune response
to diseases. When the body becomes more acidic (i.e., a pH value under 7), it also becomes more difficult for it to
assimilate vitamins and minerals.
* Urea, waste material excreted by the kidneys, is extremely toxic to body tissues
and must be diluted before passage.
* The body uses water to keep electrolyte levels balanced, and to dilute and
eliminate the salts and minerals that form kidney stones.
* Water keeps tissues moist in the eyes, ears, nose and throat.
* Water helps cushion and protect internal organs and tissues.
* The body’s water regulation systems maintain our blood and plasma at the proper
viscosity, which helps prevent heart attack and cardiovascular disease.
* Water is critical in the distribution of fibrinogen, a glycoprotein necessary for
coagulation and which may play a key role in the inflammatory response.
* Additionally, water lubricates our joints throughout a lifetime of continuous
friction and weathering. Decrease in water consumption may contribute to the development of rheumatoid
arthritis.
* Research shows that people who drink adequate amounts of water have reduced risk of
osteoporosis and hip fractures.
* Water helps to prevent constipation, bladder infection, and hemorrhoids common
during pregnancy.
* According to research at the University of Minnesota, adequate hydration maintains
skin turgidity, which helps to prevent frostbite and blisters.
* Water aids in weight-loss by filling the stomach and slowing the rate at which the
stomach empties, thereby increasing the satiety factor of food and reducing feelings of hunger and food cravings.
Additionally, adequate hydration helps keep basal metabolic rate up even during periods of caloric
restriction.
What happens if you don’t drink enough water?
Even mild dehydration can cause fatigue, headache, nausea, constipation, dizziness,
low energy levels, and heat stroke. Over the long term, chronic dehydration is associated with heartburn,
gastritis, and ulcers. The blood thickens when insufficient water is preset in the body, leading to an increased
risk of heart attack. Kidney stones occur when the body is unable to adequately dilute salts and minerals; this
crucial function of water also means that even mild chronic dehydration can also contribute to urinary tract
infections and bladder cancer. Back pain can result when the spinal discs that support and cushion the entire upper
body are inadequately hydrated.
How much water should you drink?
There are a few ways to calculate your daily water intake.
The 8x8 Method
This is the method most often cited: drink eight 8-ounce glasses of water each day,
which equals about 1.89 liters. But while many people are aware of this standard . . . well, try asking the next
three people you see how many glasses of water they’ve had today. Chances are they’ll tell you “none” if they’re
being honest. Or maybe they’ll ask whether Mountain Dew counts. (Hint: It doesn’t.)
Criticisms of the 8x8 method include the assertion that, while 1.89 liters per day
may – repeat, may – be enough for an average sedentary person, it doesn’t take activity levels, body composition,
or medical conditions into account. Additionally, while eight-times-eight might be easy to remember, this guideline
isn’t supported by solid scientific evidence.
The Replacement Method
Drink enough to make up for what you lose through normal daily activity. Urination
accounts for about 1.5 liters of water loss each day, in an average adult. You lose another liter of water through
respiration, perspiration, and evacuation. (Yes, I said respiration: you exhale one to two cups of water each
day.)
According to Mayo Clinic physicians’ guidelines, average adults get 20% of their
total daily fluid intake from food. So if our hypothetical average healthy adult drinks two liters of water along
with her usual food intake, she’ll be taking in enough to replace the water lost.
The Half-Ounce Method
Divide your body weight in pounds by two, and that’s how many ounces of water you
should be drinking each day. A 200-pound person needs 100 ounces (2.96 liters) of daily water intake.
While this may be a better guideline than 8x8, it still doesn’t account for body
composition. Muscle tissue contains more water by weight than adipose tissue, so leaner people of comparable weight
require more water to maintain equilibrium: a 200-pound bodybuilder needs more water than a 200-pound sedentary
person. This guideline is designed for a person of “average activity level” – read, nearly sedentary. Because our
lifestyle as Force Realists is anything but sedentary, we should be drinking more than that.
The Flat Rate Method
Keeping it simple, the Institute of Medicine advises men to consume three liters of
water per day, 2.2 liters for women. (Okay, it was actually 3.7 and 2.7 liters, respectively, but that includes
water from all sources, including food.) Many weight-training coaches advise even more if you work out strenuously
on a regular basis: up to a gallon (3.8 liters) per day.
The Color Method
Some experts postulate the easiest way to tell whether you’re drinking enough is by
the color of your urine: it should be clear, or at the most a very light yellow. If your urine is gold or deep
yellow, you’re not drinking enough water.
The Thirst Method
Even easier than examining your urine might be this one: Drink when you’re thirsty.
According to the Institute of Medicine, if you drink enough so that you rarely feel thirsty, and you have clear
urine, you probably have sufficient water intake.
It seems this is the method most people use. Unfortunately, it’s the worst of the
methods described here, and maybe even downright dangerous. For one thing, by the time you register thirst, you may
already be mildly dehydrated, and as we’ve seen above, even mild dehydration can spawn a host of medical issues.
Additionally, as we age our bodies’ ability to sense dehydration (and consequently send the thirst signal to our
brains) deteriorates.
When these methods are not
enough
Any of the following can affect how much water you need each day:
* Active lifestyles. Athletes, people with strenuous physical jobs, and active people
need to drink more. For a normal workout session, you need to add at least a half liter to your daily intake. A
good rule of thumb is to drink eight ounces every fifteen minutes during your workouts; cut the amount in half and
double the frequency if you experience stomach discomfort while training. Endurance athletes (those training over
an hour at a time, like marathoners and tennis players) need even more, perhaps as much as twice that. During long
bouts of intense exercise, most trainers recommend a sports drink that contains sodium, to help replace the sodium
lost through perspiration and reduce the chances of developing hyponatremia, a potentially life-threatening
condition (more on this later). Also, it’s important that you continue to replace lost fluids after your workout
session ends.
* Medical conditions. People with bladder infection, gastroenteritis, fever,
diarrhea, and vomiting should increase their water intake. However, if you have certain heart, kidney, adrenal, or
liver diseases that adversely affect water excretion, you should restrict your consumption – and you should talk to
a doctor or clinical nutritionist to get the right daily intake for your condition.
* Pregnancy and breastfeeding. According to the Institute of Medicine, expectant
mothers should drink 2.3 liters (78 ounces, or almost ten eight-ounce glasses) per day, and breastfeeding mothers
should drink 3.1 liters (13 glasses).
* Environment. People who live in hot and humid places sweat more, so they need more
water (as well as additional sodium, as described above). But people in very cold climates who spend much of their
time in artificially heated indoor environments may also perspire more; they require additional water as well.
People who live at high altitudes breathe faster and urinate more frequently, so they need more water
too.
Is it possible to drink too much
water?
It’s very rare in the U.S., but yes, there can be too much of a good thing. Drinking
water to excess over time can cause water intoxication, referred to as hyponatremia. As you consume water, blood
plasma increases and dilutes the electrolyte content of the blood. At the same time, you lose more salt by
sweating, because your body is trying to shunt off some of the excess water that your kidneys cannot process. As a
result, the amount of sodium available to the body tissues decreases. Over time, sodium deficiency can interfere
with brain, heart, and muscle functions. Endurance athletes are at higher risk. But again, this is a rare
occurrence in a healthy adult with a normal Western diet.
Summary
If all the above is too much information, some researchers believe you can manage
just fine with these easy rules:
* Have a glass of water first thing in the morning, before you do anything
else.
* Drink a glass of water with each meal and between each meal.
* Drink water before, during and after exercise.
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