©Arlene R. Taylor PhD    www.arlenetaylor.org

I start drinking water as soon as my feet hit the floor in the morning!
—Mary Kay Andrews

“The brain is supposed to be three-quarters water,” the voice said, “so that should allow for plenty of water on the brain.”

The phrase water on the brain took me back to a nursing-school lecture about hydrocephalus—described back then as water on the brain.

Returning to the conversation, I listened as the voice continued: “I mean, the brain is filled with water, so how come people are concerned about dehydration? And anyway, how could there be a connection between dehydration and brain function?”

These excellent questions, all, drove our dialogue about the brain, the implications of dehydration, and the importance of adequate hydration for optimum brain function and energy.

The caller was correct in that the brain is composed of at least three quarters water, although estimates are that neurons—i.e., brain cells--may contain as much as 85 percent water.  (Unless the person is dehydrated.) Since the brain has no way to store water, dehydration impacts not only the size of one’s brain but also how well it functions.

The Mayo Clinic estimates that:

• The average adult loses more than 80 ounces of water every day in sweating, breathing, and waste elimination, but drinks less than 32 ounces of water daily--putting him or her about 48 ounces in the hole.

• Most adults over age 50 are dehydrated. A dehydration level of 1-percent has been found to decrease your cognitve ability by 5 percent.  Bad news for your brain and body!

Dehydration is believed to be a huge problem for the brain. Researchers in the United Kingdom studied the brains of teenagers after 90 minutes of cycling. Some teenagers wore light shorts and T-shirts while others wore sweat-inducing clothing. No surprise, the teenagers who wore the sweat-inducing clothing lost the most weight--about 2 pounds in sweat. They also had the most shrinkage of brain tissue. Scans showed that the brain tissue had actually shrunk away from the skull. Just 90 minutes of continuous sweating shrunk the brain as much as an entire year of age-related wear and tear.

Also, the brains of the teens dressed in sweat-induced clothing had to work harder to process information. The participants were asked to play a computer game designed to test their ability to plan and solve problems. Both groups performed equally, but scans showed that the heavily attired teens had to use more brain power to do so. The good news? After drinking replacement water, brain size and hydration returned to normal.  Clearly, adequate water intake during activities that result in profuse sweating is mandatory.

Regarding cognitive thinking, the implications of this study are staggering. Brain dehydration may be a factor influencing not only performance of students in school but brain function in the workplace. Lack of an adequate and ongoing supply of water to the brain has been found to impair short-term memory, the recall of long-term memory, ability to do mental arithmetic, and the ability to focus and pay attention, to name just a few.  In addition, dehydration is reportedly the number one reason for daytime sleepiness and low energy.

Studies by Dr. Corinne Allen, founder of the Advanced Learning and Development Institute, reveal that brain cells need twice the energy compared to cells in other parts of the body. Water is believed to be key in providing some of this needed energy. Water is also required for the production of vital hormones and brain chemicals such as neurotransmitters. These substances are absolutely essential for clear thinking. The mere transmission of information among neurons may utilize half of all the brain’s energy.

If your goal is to maintain optimum body weight, avoid dehydration. Dehydration has been found to slow down the metabolic rate by as much as 3 percent. According to Sandra Gibson, more than a third of Americans have suppressed their thirst mechanism to the point where it is often misinterpreted as hunger.  They eat when actually their brain and body are craving water. So, by the time you are thirsty—if you are able to identify your thirst sensation—you are already dehydrated.  

For most people, the longest span of time without drinking water occurs during sleep. Since I need 9 hours per night¾and I do not disrupt my sleep by waking up to drink water¾one of my first activities in the morning involves drinking 12 ounces of alkaline water. Almost as soon as my feet hit the floor. Matter of fact, I drank another 12 ounces just before starting to write this article.

Now that it’s finished, I think I’ll reward my brain with another 12 ounces. I, for one, want enough water on my brain.

In summary, adequate water on a regular basis will help you keep your wits about you—and most people need their wits as much as they need their water!

Note: If you have a medical condition that may require limiting your intake of water, be sure to contact your healthcare professional prior to making lifestyle changes.