Water and brain function are intimately linked. Think back to the last time you went for a few hours without water - perhaps on a hot day.

How did you feel? You might have noted a headache, dizziness or faintness. You might've had a hard time concentrating or even felt irritable.

Then, remember that immense relief as you gulp a glass of refreshing water. That's your body's way of telling you just how important hydration is.

The benefits of drinking water for our general health are almost innumerable. Whether it's for exercise, helping with digestion or flushing out toxins, H2O is our fuel and the bedrock of our wellbeing.

Every function of our body is dependent on water; this includes the brain, which is approximately 75 percent water. When this organ is dehydrated, a number of undesirable outcomes can follow that we often don't stop to consider.

Indeed, a brain that needs water performs worse in almost every way. Concentration, memory and critical thinking are drastically affected. For peak function, your brain needs an optimal and consistent supply of healthy water.

Let's explore just how crucial water is for our brain's vitality and function.

Water and cognitive function: How does water help the brain?

How can drinking water help concentration?

Water is a part of our body's means of transporting essential nutrients to all the places that need them. Water aids our brain's function and concentration by giving it the electrical energy it needs to perform optimally. It also flushes out toxins.

Our body has an incredible, hard-working transportation network. This delivers hormones, elements and chemicals that are crucial for our nervous system - all suspended in water. Water hydrates our blood, getting everything moving around our body perfectly.

Our brain doesn't have a storage tank, so for optimal function it needs to be fuelled regularly. When the body is fully and consistently hydrated, this exchange of nutrients and toxins to and from our brains is highly efficient. The result? Better concentration, greater mental alertness, improved memory as well as a more balanced mood. A hydrated brain can be more creative, think with more clarity and make decisions faster.

By the same token, when the body is dehydrated, its transportation network works less efficiently; our sodium and electrolyte levels drop. This shortfall in water supply to the brain results in symptoms including problems with focus, memory and concentration. You'll be prone to experiencing headaches, brain fatigue, sleep problems and a low mood.

Dehydration and cognitive function: The research

It's not just a myth that "a drink helps you think” it's backed up by scientific research, and plenty of it.

  • In one study, people were found to have faster reaction time if they drank 500ml of water shortly before taking a reaction test.
  • In another, adults reported a poorer performance on a visual vigilance task even if they were only mildly dehydrated, also adjudging themselves as more anxious and fatigued. The dehydrated participants also reported worse memory.
  • Research found that mild dehydration in women (1.36%) resulted in "a degraded mood, increased perception of task difficulty, lower concentration, and headache symptoms".
  • In 2018, a study proved that dehydration "impairs cognitive performance, particularly for tasks involving attention, executive function, and motor coordination".

Our brain's mass is three-quarters water, so when we're dehydrated, its ability to function is impeded. Water makes the transportation of nutrients to our brain more efficient, resulting in greater cognition.

The benefits of drinking water for the brain: Older and younger people

Hydration is essential to fuel our brains for optimum function, but it does take on added significance for the elderly and the young.

The benefits for youngsters

The risk of dehydration and its damaging effects on brain function hit the very young amongst us hard. Young children and toddlers either aren't able to quench their own thirst or can forget to do so, placing them at more risk of dehydration.

Of course, youngsters still need to concentrate. In fact, concentration amongst kids is probably as important as with adults! Children need to learn, stay focused and follow instructions at school; as such, a drink of water at regular intervals can bring great cumulative benefits to education. Instilling regular water consumption as a habit can pay dividends.

Keeping water levels up when they arrive home is equally crucial. Quietly placing a glass of cool filtered water next to them as they do battle with maths homework will go a long way to helping those neurotransmitters do their work.

It's not just young kids, either. Secondary, sixth form and university students all have huge demands placed on their brains; it makes perfect sense that keeping up a hydration routine helps with exams and lectures. Water is crucial for our brain function, concentration and clarity of thinking.

Hydration and brain function in older people

Sometimes, older people have compounding illnesses or issues which can affect brain function; add dehydration into the mix, and it can exacerbate the problem. Prolonged dehydration can cause brain cells to shrink in size and mass.

There's been landmark research into dehydration in older adults as it relates to cognitive impairment. It found that lower hydration status resulted in "slowed psychomotor processing speed and poorer attention/memory performance".

That's also not to mention that a lack of water is associated with an increased risk of developing types of dementia like vascular dementia, which is caused by a lack of blood flow to the brain. We've written in more depth about the relationship between water intake and dementia on our blog.

Water quality and brain function

Not all water is created equal. Have you ever been at a friend's house, and noted a distinct difference in the taste and smell of the tap water?

This is because our water contains a number of common contaminants as part of its treatment, the most abundant and common being chlorine and fluoride. These levels vary by region.

Occasionally, heavy metals can also leach into your water supply on its way from the treatment plant. The main offenders are lead and aluminium; some areas of the UK struggle with higher heavy metal content than others.

Crucially, a prolonged exposure to drinking water with heavy metal content has been implicated in causing dementia, the awful symptoms of which we're probably all aware of - forgetfulness, poorer judgement and overall reduced brain function.

So, yes, the quality of your water can affect your brain, your ability to concentrate and your cognition. Although the UK has some of the finest water in the world, you can safeguard against potentially harmful contaminants by filtering your water with a ceramic water filtration system.

Make the change with Doulton®

Make hydration a priority in your life, for all the incredible benefits it brings to your brain - a balanced mood, more creativity, sharper thinking and better concentration.

When it comes to water, we're your people. At Doulton®, we have nearly 200 years' experience manufacturing leading-edge ceramic water filtration products and technology. Our philosophy is about excellence, and it's our mission to provide you with the very best filtered drinking water possible.

Explore our range of products; you could make the lifestyle change on the go with a stylish Doulton® TASTE water bottle, or bring great tasting, healthy filtered water to the whole family with an under-counter or Gravity filtration solution.

Daniel Berko