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Hydration and its Impact on Brain Function

how much water does the brain need each dayHumans can survive without food for several weeks but without water, life would end in three to five days. Our brain is comprised of approximately 75% water. That fact, alone, tells us how critical hydration is to the brain and body.

While we often think of food and nutrients as critical to life (they are), water is even more so. The average person can live only three to five days without water. Most can survive about three weeks without food. Now that we’ve established water is important, let’s look at how it impacts you.

Hydration its Effect on Mood

When the brain is under-hydrated are dehydrated, it physically shrinks in volume a bit. This is believed to be the cause a hydration-based headache.

Dehydration also impacts your mood. In fact, one of the earliest signs of dehydration is grumpiness. In fact, water is vital to essentially all biological functions. When you read this post, you will be shocked at how much trainers and coaches do not yet know about water.

A 2018 study of 20 healthy women in their mid-20s were deprived of all beverages for 24 hours. After just 24 hours, all participants reported:

  • Moodiness
  • Fatigue
  • Confusion
  • Decreased alertness
  • Increased sleepiness

Hydration and Cognition

Proper hydration can not only prevent headaches, it also prevents poor decisions. Dehydration impacts performance of the brain’s ability to process information, form new memories and make correct decisions. It affects visual-spatial processing and other cognitive functions.

If you go into a business meeting dehydrated, chances are higher that you will feel that sluggish brain sensation. Your brain doesn’t have the balance of fluids to operate at full efficient capacity. When you have brain fog, you are slower to process data, and slower to act on that information.

Dehydration can also have a significant impact on performance activities, such as driving. Professor Ron Maughan at Loughborough University in the UK lead a study in 2015 to evaluate the impact of dehydrated driving.

The study provided volunteers with 200ml of water on the hour the first day and had them complete a two- hour continuous driving simulator. The next day, the same simulation was repeated, but subjects were only given 25ml on the hour.

Professor Maughan found that the drivers made twice as many mistakes when dehydrated than when properly hydrated, including lane drifting, late braking and crossing the rumble strip.

“To put our results into perspective, the levels of driver error we found are of a similar magnitude to those found in people with a blood alcohol of .08%… in other words drivers who are not properly hydrated make the same number of errors as people who [drive intoxicated].”

Dehydrated driving is as dangerous as driving under the influence of drugs or alcohol.

Dehydration and Performance

Whether you are running, playing tennis, baseball, basketball or weightlifting, whether you are participating in team or individual activities, your hydration level impacts your performance. Having sufficient water in the body improves your reaction time and equilibrium (balance).

A two percent level of dehydration leads to a 10 percent drop in athletic performance. And as you exercise, hydration is compromised. It’s especially important to stay hydrated as you exercise. In addition, dehydration slows your metabolism.

Optimal Hydration Matters

Hydration matters to every aspect of the brain and body.

We know that the brain is involved in nearly every process in the body, from digestion to absorption, to circulation and excretion. But water is also important for its ability to transport nutrients and oxygen to the cells of the body and is also important in the regulation of body temperature. When people are thirsty, they rarely drink enough water to cover what has been lost. In this scenario, we see a state of chronic dehydration beginning. If water is not consumed, toxins can build up in our system, often leading to headaches and other discomfort in the body. Without water, we would poison ourselves with our own metabolic waste!

With water, it is also important to consider quality; consuming quality water is important because it is not unusual to find contaminants in tap water. This can include lead, iron, copper, fluoride, and arsenic, as well as herbicides, pesticides, and chemicals that find their way into our groundwater through the soil. Bottled water may be a better choice but there are concerns over the leaching of toxic materials from plastic materials used in the packaging they are sold in (BPA). Aside from obtaining adequate water intake to maintain optimal hydration, we also want to drink liquids that provide nutrients needed to support the brain and body.

The importance of proper hydration for optimal brain and body function cannot be emphasized enough; even the slightest level of dehydration can lead to the body becoming fatigued. If not resolved, this then leads to fatigue, emotional instability, and poor memory. We have always been told to drink eight or more eight-ounce glasses of clean water daily – but there are two main considerations to factor in, as well. First, is it accurate? How can this be the same for a 140-pound female versus a 190-pound male? Also, what about activity levels that produce sweat? The point is, know your client and their needs. Ultimately, we need enough water to flush toxins from the body. Promote drinking “plenty of water” even at times when there is no detectable thirst. The organs, especially the brain, become dehydrated long before thirst develops.

The mechanism of dehydration is the result of less cellular exchange occurring across the cell membrane. This results in greater toxicity.

Water is best, indeed. But other fluids count, too. It is common to see many people consuming a variety of beverages, so we can use this as a workaround when making suggestions that they will enjoy as much.

Water, coffee, green tea, coconut, aloe vera juice, and green juicing are all examples of fluid intake – but obviously, some are better than others. Any time your client is consuming something other than water, we must consider what other ingredients may become factors. The caffeine in coffee is one such example. As a diuretic, it will flush the body of water; the truth? Even water is a diuretic! It is important to take this seriously but not so much as to be reaching for extremes in our recommendations and guidelines to clients.

Work to eliminate any colas or juices with additives and colors, or anything containing caffeine.

A best practice for Coaches is the recommendation to consume plenty of fresh live juices. Juicing is extremely beneficial in supplying nutrients from fruits and vegetables into the diet. They help to cleanse and nourish the body and are loaded with antioxidants. When juicing with fresh, live ingredients, virtually all the plant’s health-promoting components are made available from the raw fruits and vegetables because these are from live plants. These ingredients are in a form of ingestion that is easy to digest and absorb. Green drinks made from leafy greens such as kale, spinach, parsley, celery, and cucumber should be consumed daily. Not only are they rich in vitamins minerals and enzymes, smoothies or shakes made with these items are loaded with chlorophyll, helping to purify the blood. Chlorophyll also works to build red blood cells, detoxify, and heal the body, and supports oxygenation of all tissues body. Live juicing can serve as a powerful detoxifier, working to reduce inflammation, balance immune function, enhance focus and mental clarity, support weight loss by balancing metabolism, and removing waste. There are very few strategies as powerful to improve digestion as with live juicing, and it is also a powerful way to stave off aging and elevate cellular energy levels.

Many problems related to the aging process may be attributed to nutritional deficiencies. It is believed that this may be due to malabsorption problems – or, the reduced ability of the body to assimilate nutrients properly or efficiently. Juicing with high-quality, live foods is needed for the repair and regeneration of cells. Guidelines for juicing are as follows:

  • Once fresh juice is made it should be consumed immediately as it can lose nutrients by sitting for long periods of time
  • Buy and use organically grown produce
  • Wash produce using a vegetable wash to remove any residues
  • Rotate your vegetables and fruits to get a variety of micro- and macronutrients into the diet

If you are interested in this topic, investigate the Spencer Institute Brain Fitness Coach Certification and career system.

These topics are also discussed in detail in the NESTA Fitness Nutrition Coach Certification and career training program.