You may live for 4 weeks without food, but barely 7 days without water.
How much water should you drink? Facts & Myths
FACTS ABOUT WATER
Uses and abuses
Human cells can’t function without water. It makes up 55% to 60% of an adult’s weight. It protects against such problems as kidney stones, constipation, and exercise-induced asthma. It lubricates and cushions your joints, protects your spinal cord, and transports wastes from your body through perspiration, urination, and bowel movements. It improves your mood and your immune function.
People who meet their fluid needs by drinking beverages that contain calories—sodas, some juices, or alcohol—however, need to remember to reduce the equivalent amount of calories they get from food if they wish to avoid significant weight-gain problems.
Symptoms of dehydration
Dehydration can cause deterioration in vigilance, concentration, reaction time, learning, memory, mood and reasoning. It can cause headaches, fatigue and anxiety.
When you need to drink more
You should drink more water if you have a health condition such as fever, vomiting, diarrhea, bladder infections or urinary tract stones. You may also need more water if your diet doesn’t include such water-containing foods as fresh fruits and vegetables.
Medications and water
Taking a lot of medications without drinking enough water could put a strain on your kidneys (whose job it is to remove waste from the blood).
Is thirst a reliable indicator of dehydration?
Generally speaking, the answer is yes. However, it is not necessarily so for people over 50. Dehydration for the older adult may be further exacerbated by deliberately drinking less later in the day to avoid having to go to the bathroom at night.
Can you drink too much water?
Yes. If you drink more water than your kidneys can process in a reasonable amount of time, it can result in swollen cells and dangerously low blood levels of sodium and other electrolytes. In extreme instances, this can become life threatening. Symptoms include headaches, confusion, fatigue, and irritability.
No scientific guidelines exist on how much water a given individual needs to drink each day. The amount must be determined by a person’s weight, age, activity level, environment, medications, and what they eat. In addition to the various liquids a person drinks, there is also moisture in foods such as fruits, vegetables, soups, and even meats. Typically, moisture in food accounts for about 20% of a person’s liquid intake.
Dark urine doesn’t always mean you’re dehydrated. Urine can also turn dark from eating foods such as asparagus, blackberries, and beets.
Drinking eight glasses of water daily will not prevent dry skin and wrinkles (if you are otherwise hydrated). You’d be better off using a good moisturizer and a sunblock with an SPF of at least 35.
Bottled is no better than tap water, according to some studies done by environmental groups. In fact, an estimated 25% or more of bottled water is simply tap water, which is sometimes treated, but often is not.
For more information:
• nytimes.coms- dehydration risks
• grandparents.com - how much water to drink
• businessinsider.com - surviving without water?
• adventure.howstuffworks.com - living without food and water