The Water Myth: How Much Water Should You Drink a Day?

This is a guest post by Dr. Michael Teplitsky, author of Nutrition and Your Health. Dr. Teplitsky has no problem busting conventional health myths and bringing you the real scoop on what it takes to be healthy. You can read my interview with him at this post and find out more about his books here.

The myth – drink 8 glasses of water a day to stay healthy.

This is something that we have all heard repeatedly. This is the reason why so many people are walking around with bottles of water. They guzzle it as if their life depended on it. Every “expert” tells you to do it. But is it true? No.

It is true that we all need water. The bulk of your body is water, about 60% if you are a man, 55% if you are a woman. Muscles contain about 75% water, blood is 95% water, and even the hard solid bone has 22% water. About 2/3 of the water is inside the cells and 1/3 is outside, in the blood and other body fluids.

But does it mean that you have to gulp down gallons of water? Absolutely not. In fact, next time you hear someone tell you that you must drink 8 glasses a day, ask them where they got this information. They will not be able to tell you because there is no medical justification for this advice. Let me say that again. There are no medical studies that support the idea of drinking 8 glasses of water a day.

Nobody knows where this idea came from. But I suspect that the bottled water producers have something to do with it. Taking a few pennies worth of water and selling it to you for $1.50 to $2.50 (more if you live in New York City) is a very profitable business. The more bottles of water you buy, the more money they make. That’s all there is to it.

So don’t feel guilty if you can’t seem to gulp those 8 glasses. The truth is that you do not need them!

One recent study in the Journal of American Society of Nephrology (April 2008) has completely debunked the water myth. Nephrology is the study of kidneys, the organs that make urine and control how much water is removed from the body and how much stays behind.

Doctors have examined all the studies about drinking water and health from 1970s to the present. They have not been able to find a single study to support the 8 glasses a day myth. They have also found that other commonly believed ideas about water have no justification in any scientific research.

Many people believe that drinking a lot of water:
  • removes the toxins from the body
  • makes your organs work better
  • makes you eat less and lose weight
  • improves your skin

None of this is true and there isn’t a single medical study to support any one of these beliefs.

The researchers did find that as you drink more water, your ability to filter toxins out of the blood actually goes down. They found no evidence that drinking a lot of water improves your skin or any other organ.

You only need a certain amount of water in your body at any given time. If you force more water than your body needs, your kidneys will simply get rid of it by making more urine.

So the more water you drink, the more extra work your kidneys have to do. If you gulp a lot of water quickly you also run a risk of creating an imbalance between different electrolytes in the blood. Too much water can reduce the level of potassium, which can be dangerous.

Now, this does not mean that you should not drink at all, only that you should not force yourself to guzzle 8 glasses if you don’t feel like it.

A few more myths about water and I will tell you how much you really need.

“If you feel thirsty, you are already dehydrated.” This is a bunch of nonsense. Thirst is your body’s way of telling you that you need more water. All animals, including our relatives the apes, drink when they are thirsty and they seem to be doing okay. The idea that you should drink so much that you never become thirsty is insane. Our ancestors have survived for thousands of years without gulping gallons of water every day. They only drank when thirsty, which is the most natural thing to do.

 “Caffeine in coffee and tea can dehydrate you.” This is another lie designed to make you reach for your bottle of water.

Don’t listen to this propaganda. It is designed only to make the bottle water makers rich, not to make you healthier. Here is what you need to know about water.

All the natural things you eat have water in them. Just like your body is made of 60% water, all the plants and animal tissues have plenty of water. Vegetables and fruits have 80 to 95% water, fresh meat up to 75% water. So you can’t avoid getting a lot of water if you are eating natural foods. Of course this is not true if you eat mostly processed foods, such as breakfast cereals, potato chips, etc. In that case you need to drink water (if you are thirsty).

How Much Water Should You Drink a Day?

How much water do you need? The rule of thumb has to do with the color of your urine. If your body does not have enough water your kidneys will try to conserve it, so your urine will be concentrated. It will look dark and may have an odor. If you have enough or too much water, your kidneys will not have to conserve it and your urine will look pale or even white and without any odors. Next time you urinate take a look. If your urine is dark it means you need more water, otherwise you are getting enough.

One final word of caution – avoid plastic bottles. Plastic contains a very harmful chemical called bisphenol A (BPA). Besides being a common component of many plastic products it is used extensively in various food and beverage containers and in other plastic containers. There is so much of it around that it is now possible to measure it in our blood and urine. A recent study in the Journal of American Medical Association (September 2008) has shown that the higher the level of BPA in the blood, the higher the risk of many health problems, including diabetes, heart disease, and liver problems.

This post is part of Real Food Wednesday hosted by Kelly the Kitchen Kop!

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