Hydration and Brain Health; Is It All Just Hype? - Written by Doreen Bridgman

Recently, I saw an example of the importance of hydration on brain function. This became all too clear to a friend of mine  - and she learned this lesson the hard way. 

She became dehydrated while walking outside on a hot day and began to show signs of cognitive decline. Ultimately, she had to be hospitalized after her cognition became so impaired, that it adversely affected her judgment, which led to a serious fall.  

The need for hydration is not just a thirst thing... it’s a brain thing. 

You probably already know that your kidneys, heart, lungs, and muscles are dependent on water.  But do you know that your brain is about 75% water? That's why getting proper hydration is so important for your brain to function optimally.

What happens to your brain if you become dehydrated?

• You may experience reduced cognition.  These changes may become obvious, even with mild dehydration. The decline can become more obvious as you become more dehydrated.  Moderate dehydration may cause you to have trouble paying attention, have difficulty with short-term memory, and it can become harder to make good decisions. In particular, elderly people need to closely monitor their level of hydration, as they may already be mildly dehydrated once they begin to feel thirsty. These cognitive changes can increase the risk of physical injuries as well.

• Your emotional well-being and mood can be adversely affected.  Dehydration can lead you to become irritable, experience mood swings, and have higher levels of stress. A well-hydrated brain is better able to regulate emotions and manage stress more effectively, so you can cope more easily when things don’t go your way. 

• You may feel less energetic.  Are you tired because of exertion, or could you be dehydrated?  A dehydrated brain means you’ll need to work harder to complete even routine tasks; this energy expenditure can make you fee more fatigued.  Adequate hydration allows your energy levels and mental alertness to remain high.

• You may get a headache. Dehydration is a common trigger for headaches and migraines. Headaches and migraines can negatively impact your ability to pay attention and focus, which can negatively impact your ability to function. 

• Your brain structure and function can change. Chronic dehydration can have negative, long-term effects on your brain structure and function.  Chronic dehydration has been linked to a higher risk of cognitive decline and neurodegenerative diseases, such as Alzheimer’s disease.  Maintaining consistent hydration can help protect your brain’s health as you age.

When we think about dehydration, we often think the cause is not drinking enough fluids, but there are other causes as well, such as:

• An inconsistent sleep schedule. Getting too much or not enough sleep can cause dehydration. This may be related to the disruption in your natural circadian signal, interrupting the signal that tells your body to hold on to fluids late in the normal sleep cycle. On the other hand, sleeping for too long may result in too much time between fluid replenishment.

• Flying in a plane. Because the cabins of airplanes are controlled environments with much lower levels of humidity than typical air, your fluid and hydration levels may be reduced by the end of your flight.

• Drinking alcohol. Alcohol can suppress the hormone vasopressin, which acts to hold onto water in your body. Drinking alcohol may also cause you to visit the bathroom more often, reducing your hydration as well. 

Following are some suggestions to stay hydrated for optimal brain function:

• Consistently drink water regularly throughout the day. Plan to drink half your body weight in ounces per day; increase intake with activity. Some smartwatches now give you reminders to take sips of water repeatedly throughout the day. 

• Eat hydrating foods. Incorporating foods with high water content into your diet such as fruits and vegetables can help keep you hydrated.

• Carry a reusable water bottle. Keeping water accessible throughout the day will make it easier to stay hydrated. The water bottle will also be a visual reminder to take a drink.

• Establish a regular sleep routine. Aim for 7-9 hours of sleep per night. If you tend to wake up during the night to visit the bathroom, it’s best to stop drinking liquids after dinner. To get the day off to a good start, drink a full glass of fresh water as soon as you wake up for the day.  

• Limit your alcohol intake. Alcohol is dehydrating. So, when you do drink alcohol, alternate between water and alcohol to offset the dehydration.

• Hydrate before and after plane flight. Drink a glass of water before a flight to keep you hydrated during your travels. Drinking afterward will replenish any water lost during the flight.

See you at the water cooler!

For more information on how to optimize your cognition, and the factors that impact it, or to learn more about the Long Live Your Brain program, visit our website at longliveyourbrain.com.

DOREEN BRIDGMAN, MS, CCC-SLP-CBHC is co-owner of BrainThrive Consulting and owner of The Cognitive Coach LLC.  Doreen is the co-creator of the ©Long Live Your Brain Program, an online brain health program to increase cognitive reserve, improve attention and memory and allow people to stay engaged in their daily lives.  Visit www.longliveyourbrain.com for more information.  Doreen is an Amen Clinics Certified Brain Health Coach and a licensed Speech-Language Pathologist.