Feature Articles: Food, Fitness and Health
Drenching the Water Myths
Janet Hackert, Northwest Regional Nutrition and Health Education Specialist, University of Missouri Extension
Water is an essential nutrient, yet there may be some misconceptions about it. The July 2008 issue of Tufts University Health and Nutrition Letter dispels some of these myths.
Water is crucial for human life. Blood is, on average, 92%
water, and other parts of the body, such as muscles and
brain, are 75% water. Water is needed to control body
temperature, to lubricate and cushion joints, to transport
nutrients, and to remove waste.
But there are myths about water that have been drenched.
Here are some of them.
Myth: People require eight 8-ounce glasses of straight water
daily. In fact, in 1945, the Nutrition Council found that
people do need approximately 64 ounces of water every day.
But that water can come from straight water or other
beverages like milk and juice. It can also come from foods.
Some foods’ water content is more obvious than others’. For
example, it is no surprise that watermelon is 91% water by
weight and grapefruit is 89%. Broccoli is also 89% water by
weight and carrots are 88%. Roasted chicken with no skin is
65% and even whole wheat bread is 38%!
Myth: Caffeinated beverages, such as tea, coffee and
caffeinated soda or pop, don’t count in getting enough water
for the day. Actually, caffeine does have a diuretic effect
(that is, it draws water from the cells), but a person would
have to consume a huge amount for this to take place.
Myth: By the time people feel thirsty, they are dangerously
dehydrated. In a healthy adult, thirst comes when blood is
concentrated by about 2%. “Dehydration” is defined generally
as concentration by about 5%. According to the Institute of
Medicine, “Fluid intake, driven by thirst… allows
maintenance of hydration status and total body water at
normal levels.” So drinking to satisfy thirst works to
maintain that balance. A caution would be for older adults
for whom the sensation of thirst does not kick in as
quickly. Especially on hot summer days (or cold, dry ones),
older adults should be a little more conscientious about
staying hydrated.
Last update: Tuesday, May 05, 2009
 |
Site Administrator: |
|
|
|
