The Many Benefits of Water for the Brain

Camille Freking, MS Translational Pharmacology and Clinical Research
The Many Benefits of Water for the Brain

Water is universally accepted as the primary element of life. Every living organism that exists in the known universe needs water to live. 

People, plants, animals, and bacteria all rely on important chemical reactions that are only possible via water. In fact, you can only go about three days without water before it’s lights out.

Suddenly feel like you want to go into the kitchen and pour a tall glass for yourself? We don’t blame you. Go ahead and grab that life-giving H2O and settle in — there’s a lot of information to cover, plus staying hydrated is proven to help you absorb info.


Why Is Water So Important?

Anything with the moniker “the element of life” must be pretty important. You probably already know that water has a chemical composition of two parts hydrogen and one part oxygen, but that doesn’t help to explain why it’s essential to life throughout the universe. 

The easiest way to understand the importance of water is to look at these average estimates for the human body:

  • 31% of your bones are water 
  • 64% of your skin is water
  • 73% of your heart is water
  • 73% of your brain is water
  • 79% of your muscles are water
  • 79% of your kidneys are water
  • 83% of your lungs are water
  • 60% of your total body weight is water

Water is especially important to infants, as babies are born with about 78 percent of their bodies being water. By adulthood, the number decreases to “only” about 60 percent of your total composition. Seeing how most of your body is water, it can be easy to understand why water is so important. 

Here are a few examples of essential bodily functions that water makes possible:

  • Regulation of body temperature with sweating and respiration
  • Elimination of waste through perspiration, urination, and bowel movements
  • Transportation of oxygen, nutrients, carbohydrates, and proteins within the bloodstream
  • Breakdown of vitamins and minerals to help the body absorb them more efficiently
  • Protection of organs and tissues from trauma
  • Lubrication of joints, eyes, nose, and mouth
  • Creation of saliva that facilitates digestion

Of course, these are just the processes that directly involve water. If you take into account that every cell inside of your body is more than 70 percent water, then technically, every action that every cell performs involves water. 


What Does Water Do in the Brain?

There isn’t much in the natural world that can rival the incredible processing power of a human brain. However, none of this spectacular brain power would be possible without an adequate supply of water. 

Naturally, something that makes up nearly three-quarters of the brain’s composition will be essential in many ways. Perhaps the easiest way to convey the role of water in the brain is by discussing what happens without it.

The effects of dehydration are generally experienced in the brain very early on. Even a mild case of dehydration (roughly four to eight hours without water, or two percent loss of water weight) can lead to several undesirable symptoms

Short and long-term memory difficulties, fatigue, irritability, and headaches can often result from merely lacking sufficient water in your brain. 

There are two main reasons that you can experience these issues after just a few hours without water: 

  • The brain isn't capable of storing water. While the brain contains a lot of water, all of it is being used, so there’s no room for extra. There isn’t really anywhere in the body that can properly store water. Whatever you drink is either put straight to use or removed through urination.

  • The brain depends on your blood to provide oxygen and essential nutrients. Low water levels in your body will decrease blood flow to your brain. The disrupted supply can cause the brain to struggle with even the most common everyday functions.

If the symptoms of dehydration are addressed fairly quickly, then there is usually not much of a concern. The brain can bounce back and return to normal levels of operation quickly. However, prolonged or frequent periods of dehydration can have significant long-term effects on your brain.

The gray matter in your brain can shrink, you could start to experience seizures, and your brain can age prematurely. 


How Much Water Should You Drink Each Day?

You’ve probably heard before that you should drink at least eight cups of water each day. While eight cups is a good start, experts recommend a little more. 

According to the United States National Academies of Sciences, Engineering, and Medicine, here is how much water you should be drinking each day:

  • Women need to drink at least 11.5 cups (2.7 liters) of water
  • Men need to drink at least 15.5 cups (3.7 liters) of water

It’s important to keep in mind that these are just the basic recommendations. Several additional factors could increase your daily recommended intake of water, including height, weight, age, diet, overall health, and lifestyle. 

  • Physical attributes such as height and weight can greatly increase the volume of water in your body. Naturally, someone that’s 6’3” and weighs 225 pounds will need to drink more water than someone who is 5'7” and weighs 165 pounds. Larger individuals possess higher energy requirements and require higher nutrient input. Each of these will require an increase in water consumption.

  • Infants, children, and the elderly will all need more water than the average adult. Young people’s bodies are still developing and utilizing a tremendous amount of water to grow. For older people, changes to their body composition and temperature regulation affect water requirements.

  • Diet can have a massive impact on the overall water levels in your body. Eating foods high in salt (such as processed foods) can lead to your body retaining water. Alternatively, drinking caffeinated or alcoholic beverages can cause you to become dehydrated more quickly as they promote urination. The best course of action is to eat plenty of fresh fruits and nutritious vegetables, as they’re almost entirely composed of water.

  • Being sick (whether a weekend bug or chronic illness) often leads to tremendous water loss in your body. This is why a doctor may strongly recommend that you drink plenty of fluids when you’re sick. Fever sweats, blowing your nose, vomiting, and diarrhea are common symptoms of most illnesses and can quickly deplete your water supply. You’ll need to make up for the loss of this water by increasing your fluid intake.

  • The amount of physical activity you get each day is another factor that can drastically alter the water you need to drink daily. Athletes can lose as much as 12 percent of their water weight when performing endurance exercises. The water lost needs to be replenished quickly to avoid dehydration.


    How Can You Tell If You’re Not Drinking Enough Water?

    Drinking the right amount of water is far from an exact science. Knowing if you’re getting enough water can be difficult, especially when you have to factor in some of the abovementioned factors. 

    The only way to truly know if you’re getting enough water is to look for the early warning signs of dehydration.

    If you’re experiencing one or more of the following issues, you might need to increase your plain water intake (i.e. increase your intake of good old fashioned water, not more juice, coffee, or tea):

    • Constantly feeling thirsty
    • Easily fatigued, exhausted, or lethargic
    • Feeling hunger pangs despite eating regularly
    • Mouth, eyes, skin, or hair feel dry
    • Urine is a dark shade of yellow
    • Infrequent trips to the bathroom
    • Rapid mood swings and easily irritable
    • Often disoriented or have difficulties with cognition and attention
    • Memory lapses or issues with recalling specific details
    • Increased sensitivity to pain
    • Muscle cramps
    • Headaches

    As always, consult your healthcare provider if you’re not feeling like yourself or if you notice the above symptoms — many of these symptoms can be a part of an underlying condition that needs to be diagnosed by a profession.


    What Are the Benefits of Having Enough Water in Your Brain?

    In one of the earlier sections, we briefly touched on some of the things water does for your brain. In this section, we will look at exactly how water benefits your brain. 

    Here are five different ways that drinking enough water can benefit your brain: 


    Brain and Spinal Cord Protection

    The brain and spinal cord are cushioned by cerebrospinal fluid (CSF). CSF is about 99 percent water, and a healthy adult has anywhere between 100 to 150 milliliters in their body. CSF flows through the ventricles in your brain and coats the brain and spinal cord. 

    The liquid helps to soften the impact and absorb some of the damage that occurs during trauma. You probably already know how dangerous a concussion can be to your brain. Imagine how much worse the damage would be without CSF acting as a shock absorber. 


    Flushes Out Waste and Toxins

    You probably already know that sleep is extremely important for the brain. During sleep, CSF performs another essential function: flushing out the dangerous chemicals that have accumulated in your brain. 

    The various functions performed by your brain will naturally produce waste byproducts throughout the day. If left uncleared, they can eventually become toxic and work to poison your brain. Having an adequate supply of CSF and sleep each day is the only way to remove them. 


    Supplies Your Brain With Nutrients

    Blood might be thicker than water, but only by a small margin, as blood is about 90 percent water. The brain relies on blood and CSF to provide it with the various nutrients it needs. Oxygen, minerals, and vitamins are all supplied by these two fluids. 

    Having enough water in your body is essential for helping nutrients flow to your brain. A reduced flow of oxygen and important nutrients could have a ripple effect and negatively impact your decision-making, concentration, long and short-term memory, cognitive function, and overall brain performance. 


    Improves Your Overall Mood

    Water helps to provide the brain with the electrical energy needed to achieve certain functions. One of these functions is the production of neurotransmitters. The primary purpose of neurotransmitters is to act as messengers within the brain.

    Serotonin is one of the most important neurotransmitters, as it helps to regulate your body’s everyday functions. Along with stabilizing your mood, the so-called “feel-good hormone” also plays a regulatory role in learning, memory, body temperature, sleep, hunger, and sex drive. 


    Stay Hydrated To Keep Your Brain Healthy

    There’s no way to overstate just how important water is for your brain. It’s the single most important thing you can provide for your brain. 

    Everything in your brain relies on some amount of the “element of life” present. The only way to ensure proper brain function is by supplying it with adequate water daily. Keep your water bottle close at hand.

    Be sure to also add in enough sleep each night and include plenty of foods that support brain health. It doesn’t take long for a dehydrated brain to start experiencing extreme side effects. It’s best to avoid them altogether by making sure you’re drinking enough water throughout the day. 

    Looking for more info on how to support your brain? Explore MOSH’s mind wellness blog here!



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