Cool, clear water
Ben Kallen
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Cool, clear water: you're surrounded by it, and you can't survive without it. But how much [H.sub.2]O do you really need? Should it be tap or bottled? And just how clean is your home supply? Lisa Ryan doesn't take a bottle of water when she leaves for work in the morning--she carries a whole trunkful. She drinks before, during and after her morning workout, and has a bottle at the ready anytime during the day. "If I'm dehydrated, I get really tired," says Ryan, a San Diego advertising account executive. "But when I drink water regularly, I have more energy." It's true: Water enables the loading and storage of energy-giving glycogen in your muscles. It also regulates your body temperature; aids in digestion, circulation and joint lubrication; maintains blood volume; flushes toxins from the liver and kidneys; and helps decrease the risk of numerous cancers by 50 percent or more. Without it, you wouldn't last more than a few days. |
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why water?
So, five glasses, eight glasses ... does it really matter? It does if you want your body and brain to function properly, says Stella L. Volpe, Ph.D., R.D., associate professor of nursing and the Miriam Stirl Term Endowed Chair in nutrition at the University of Pennsylvania.
Mild dehydration can slow your metabolism by as much as 3 percent, and lead to fatigue and cloudy thinking. "People who are mildly dehydrated might notice a decrease in their physical performance or have muscle cramps, and they might have decreased cognitive function" Volpe says. Since these symptoms can be mild, people suffering from them may not realize they aren't at their best.
A lack of adequate fluids stresses the heart and raises core body temperature quickly, especially during exercise or in hot climates. That's what leads to more serious conditions like heat prostration or heatstroke.
the right amount
So how much [H.sub.2]O should you get each day? The answer is, shall we say, fluid.
The "eight 8-ounce glasses a day" is a generalization that continues to be taken literally, says Heinz Valtin, M.D., a retired Dartmouth Medical School physiology professor and author of two widely used textbooks on water balance and the kidneys. "I was asked to find a scientific basis for that recommendation, and I couldn't," he notes. Thus, one 64-ounce size doesn't fit all. The average man needs more than the average woman, as do athletes of both genders. But it's rarely necessary to break out the measuring cups, emphasizes Valtin. "Drink what you would drink customarily at and between meals, plus more when you're thirsty" he advises.
In other words, your morning coffee, the smoothie with lunch and the soft drink with dinner an go toward fulfilling your water needs, and drinking whenever you feel the urge will fill in the gaps.
The meals themselves will also provide fluids. A recent report by the Institute of Medicine of the National Academies extensively reviewed hydration and electrolyte intake and determined that water in food should count toward hydration, as should sports drinks, caffeinated and even alcoholic beverages, The report, in which Volpe participated, provides slightly more regimented rules than Valtin does. It recommends 2.7 liters (91 ounces) of fluid per day for women, and 3.7 liters (125 ounces) for men. Of that, 81 percent will probably come from beverages, and 19 percent from food.
"Liquid drinks are 90 to 95 percent water; says Valtin. "Fruits and vegetables are mostly water. Even a piece of white bread is about 30 percent water." (For delicious ways to add water to your diet, see "Juicy Foods" on page 88.)
pangs of thirst
Hungry? Try a glass of water first, since many people mistake their thirst for hunger. Water even eliminated late-night hunger pangs for most dieters, according to a study at the University of Washington.
Otherwise, thirst is a perfect indicator of a need to drink, Valtin says, a conclusion supported by a recent study in the American Journal of Physiology. Still, many experts believe that if you're thirsty, you're already slightly dehydrated, especially if you're physically active. The American College of Sports Medicine recommends consuming 500 milliliters (about 17 ounces) in the two hours preceding a workout, plus another 5 to 10 ounces every 15 minutes during exercise and in the first hour after.
One way to tell if you aren't drinking enough is to weigh yourself before and after a long workout; if you weigh less, you're dehydrated. (If you weigh more, you may be drinking too much. Normally, your body excretes what it doesn't need, but in extreme cases involving triathletes or marathon runners, too much water can lead to a dangerous shortage of salt, a condition called water intoxication or hyponatremia.)
Another way to balance your intake, Volpe says, is to look at your urine: "It should be a pale yellow. If it's clear yellow, you might be overhydrating. If it's a dark yellow, you may not be drinking enough." She adds that changes in urine color also can result from taking vitamins or other supplements.
Your body is very efficient at regulating its water levels, says Valtin: "The moment you drink a little more than usual, that system goes into effect and you pee more. The moment you don't drink enough, you retain more in your body."
For her part, Lisa Ryan is more than happy to retain her water regimen. "When I don't drink enough, I feel listless, and my skin and eyes feel dry," she says. "But when I listen to what my body needs, I always end up feeling better."
filtration and purification
By Kyle Roderick
Water is essential for your health, but just how healthy is your water?
The quality of drinking water and bath water varies dramatically throughout the United States. A certain amount of contaminants are allowed by the government. Visit the Environmental Protection Agency's Web site (epa.gov) to find the maximum levels for 90 drinking-water contaminants, including heavy metals, endocrine-disrupting chemicals, fecal coliform, fuel additive, giardia and other pathogens. While numerous chemicals have been identified in drinking water, the EPA has established safety standards for only a limited number of these.
"In some areas of the U.S., outdated sewage systems are contributing to contamination of water supplies," says Navis Bermudez, spokesman for the Sierra Club's Clean Water Campaign. "The EPA estimates there are 400,000 backups of sewage in basements each year, but the number may be higher."
Happily, water filters and purifiers can help rehabilitate your water supply. Distillation is the surest method of water purification; it's also the most expensive. The process consists of boiling water and then converting the steam back to water, killing bacteria and viruses and removing heavy metals and contaminants, though it can remove healthful minerals, too. It's also a slow process with limited results, producing anywhere from 3 to 12 gallons a day. Purchased distilled water is theoretically safer than tap, but the quality of bottled water varies. Request content and bottling information before choosing a bottled-water delivery service.
Reverse osmosis is also effective, but about as slow as distillation. Options that are more practical include carbon, ceramic and other filters that remove organic contamination and chemicals. All filters require periodic maintenance and replacement; otherwise, they become a point of concentration for the very contaminants you're trying to eliminate. If that seems to be a hit of a bother, just consider the results.
"The benefits of using water filters and purifiers include reduction in long-term consumption of and exposure to toxins, heightened lymphatic and immune system functions and reduced cancer risk," says Dharma Singh Khalsa, M.D., author of Food as Medicine. "If you are pregnant or have children, using these systems can be especially crucial to your health and well-being."
* Portable water systems, such as those made by Brita, filter for chemical impurities, but not for bacteria, However, the manufacturer of Bottom's Up claims that this travel-sized filter/purification bottle eliminates or reduces up to 99.8 percent of bacterial pathogens such as giardia and cryptosporidium, PCBs, pesticides and heavy metals. It has a filling capacity of 200 gallons, or more than 1,000 refills ($24; raytechstore.com/msm/bottoms.htm).
* PUR Ultimate Faucet Mount Filters are excellent choices for kitchen or bathroom sinks. For cold-water use only, they come in white plastic or chrome; the vertical-mount model has a swivel sprayer, while the horizontal one is most appropriate for shallow sinks. These carbon filters last two to three months ($35-$45; airdelights.com).
* If you prefer your system out of sight, Paragon's under-the-counter titanium silicate/carbon filter easily mounts beneath the sink. Weighing 3.5 pounds, it's for cold-water use only and needs replacement filters once a year ($139; gaiam.com).
* The Shower-Cleen Triple Shower Filter removes odors, bacteria, chlorine, volatile organic compounds, organic waste, and common carcinogens such as carbon tetrachloride, benzene and chloroform. Containing a 5-micron sediment filter, a granular activated-carbon filter and a bacteriostatic filter medium, it's easily mounted and lasts three to six months ($99, and $15 for replacement filters; realgoods.com). * The Bath Ball Faucet Filter will remove chlorine. This ball-shaped filter attaches to the faucet with a vinyl strap. Water courses through openings in the filter top and flows out 95 percent chlorine-free. Besides sparing you from inhaling chlorine and endocrine-disrupting organochlorines, this filter makes bath water smell cleaner and feel softer. Measuring 4 inches in diameter, the filter must be replaced annually ($49, and $32 for replacement filters; gaiam.com).
what's in that bottle?
There's more--and sometimes less to water than meets the eye. Here's how to know your eau. says the International Bottled Water Association:
spring water
comes from an underground formation in which water flows naturally to the earth's surface.
purified water
has gone through a process to rid it of minerals and contaminants such as distillation (turning into steam), deionization (which removes ions) or reverse osmosis (a filtering system). This leaves a "clean" taste, although the purifying method can alter the flavor.
mineral water
comes from an underground source and contains no less than 250 parts per million total dissolved solids--meaning minerals such as calcium. These must be in the water at its source and can't be added later. Mineral waters tend to have a distinctive taste, but the amount of minerals isn't usually high enough to meet your daily recommended intake.
sparkling bottled water
has a mild fizz caused by carbon dioxide that was in it at its source--and that can be added back if a certain amount was lost during treatment.
artesian water
is taken from an aboveground well that taps an aquifer, a water-soaked layer of rock or sand.
well water
is extracted through a hole drilled into the ground to tap the water aquifer.
soda water, club soda, seltzer and tonic water
are considered soft drinks rather than bottled water, and aren't regulated under the same rules, Unlike bottled water, they're allowed to include sweeteners and chemical additives.
do you really need to drink bottled water?
With 700 brands to choose from, 70 percent of Americans spend $7 billion annually on bottled water. These products cost 240 to 10,000 times the average cost of tap water, but what are we getting in return?
Perhaps one-fourth of bottled water actually comes from municipal sources. It must be clearly labeled as being from a community or municipal supply, unless it's processed sufficiently to be "distilled" or "purified" water; Aquafina and Dasani, for example, are both purified tap water. Other choices can be confusing: Spring water and mineral water both come from underground sources, while tonics and soda waters aren't even legally defined as water. (See "What's in That Bottle?," opposite.)
The latest trend is to enhance water with healthful additions like calcium, soy, vitamins, electrolytes, vegetable extract, ginkgo biloba and echinacea. But the amounts added are generally so small that nutritionists don't recommend them as primary sources of nutrients. Also, some of these ingredients change the taste of the water, which manufacturers are camouflaging with sweeteners and flavorings that can take the calorie count from zero to 10, 30 or even 50 per serving.
So back to tap: Is it safe? "As long as you're drinking water from a municipal water supply, the water is subject to government safety standards for safe drinking water," says Judy A. Harrison, Ph.D., associate professor and food-safety specialist at the University of Georgia. "If you get your water from a well, it is your responsibility to get the water tested. You are more likely to encounter well water in places that do not have access to municipal water, like rural areas."
Still, some municipalities have higher levels of contaminants than others. A test in 1996 found that nearly 10 percent of community tap-water systems violated Environmental Protection Agency treatment or contamination standards. (To check your area, go to the EPA's Web site at epa.gov/safewater/dwinfo.htm.) In homes with old or poorly maintained pipes, lead may leach in from pipes, joints or solder, and even new lead-free pipes can raise lead levels in the water for several months after installation. Recently, the water reaching thousands of homes in the Washington, D.C., area was found to have exceedingly high levels of lead, which has been linked to impaired brain development in children and heart disease, strokes and cancer in adults. Significant lead contamination is likely in many other systems nationwide, according to testimony heard before the House Government Reform Committee.
Home water-test kits, such as Watersafe ($15; at drugstore.com), can ascertain the presence of lead, bacteria, pesticides, nitrates and chlorine. And numerous home products help filter these and other contaminants from your water supply. (See "Filtration and Purification" on page 108.)
If you take these precautions, you probably don't need bottled water. Still, if you prefer its taste (or lack thereof) and it helps you stay aware of your hydration needs, you'll end up drinking more. But refrigerate the bottles after opening to avoid bacterial growth. And recycle: Each year, more than 14 billion plastic water containers (1.5 liters or less) end up in the trash, according to the Container Recycling Institute.
"What's most discouraging is that these bottles can be used for so many things," says Darryl Young, director of the California Department of Conservation, which has found that only 16 percent of polyethylene terephthalate water bottles sold in the state are recycled. "Recycled PET water bottles can be used as raw material to make sweaters, carpet, T-shirts and even products for the home."
COPYRIGHT 2004 Weider Publications
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