With an ageing population, the dementia challenge is growing rapidly in the UK. There's an estimated 850,000 people living with dementia in the UK. Unfortunately, health experts estimate that diagnoses are set to soar by 57 percent by 2040.

Already the leading cause of death in England, dementia is a truly devastating illness for the sufferer and their loved ones. Dementia is a name of a group of diseases that result in decline of brain function, the most common being Alzheimer's.

What can be done, however? Undoubtedly, genetics plays a huge role in our health journey, but conscious decisions we take can have an effect. Our well being partly comes from a series of life-long, "modifiable" choices - those we make now could prove to be vital to our health in later life.

But just how significant is adequate hydration for brain function, and what does the latest research tell us about the relationship between water consumption and dementia? 

Lifestyle choices & preventing dementia: How hydration plays a role

At present, there is no cure for Alzheimer's - the most common form of dementia. As such, prevention is key.

In-depth research, collated from work by 24 international experts, estimates that the development of dementia can depend by 35% on potentially modifiable risk factors. Water intake and hydration plays a key role here.

A good hydration routine helps to support exercise, diet and energy levels. Not drinking enough water can leave people feeling lethargic and listless, scuppering good intentions to exercise and eat healthily.

There is a knock-on effect here, too - exercise is proven to help with depression, increasing social interaction (when done in groups), and helps to keep hunger at bay. A healthy life-style is the sum of all parts. Drinking water is a force for good flowing through it - the bedrock of any healthy lifestyle to prevent dementia. Although dementia is diagnosed in later life, the brain changes usually begin to develop years before. Acting now will vastly improve life for people with dementia and their families and, in doing so, will transform the future of society.

The relationship between brain health, dementia and water consumption

Water is crucial for our brains. When we drink water, our blood is hydrated and easier able to travel around the body, transporting oxygen and essential nutrients to places that need it - which include the brain. When we are even mildly dehydrated, this process can be inhibited. As such, dehydration and brain function are intimately linked.

Water plays a vital role in the way brain cells work and helps to remove toxins. If the body starts to become dehydrated, the functioning of brain cells is affected. In the case of long-term dehydration, this can even age the brain.

Dehydration can cause symptoms similar to those of dementia, including memory loss, confusion and depression. Even in mild cases of dehydration, 1-3% of body weight, studies show that headaches increased, concentration decreased, anxiety increased and mood was affected. Similarly, other research shows that lower hydration "slowed psychomotor processing speed" and resulted in poorer attention and memory performance.

Another key study noted that dehydration conditions impaired cognitive abilities (i.e. perceptive discrimination, short-term memory. A clear relationship between cognitive performance and hydration.

Can a lack of water actually cause dementia?

Clearly, dehydration can cause dementia symptoms by impairing our cognitive function - inducing memory loss, confusion and depression. But does it cause dementia itself?

The answer is not crystal clear, but there is some evidence to suggest that it does. A comprehensive study of neurocognitive disorders concluded that "dehydration was associated with the risk of developing a type of dementia, like AD or vascular dementia."

As always, the advice of experts is always the same - water is excellent!

How much water should someone with dementia drink?

Understanding the relationship between dementia, dehydration and cognitive function may prompt us to question our water intake.

Dehydration in dementia patients can be a real issue — for those living with the disease, it can be challenging to remember to take on enough water. So what's a good fluid intake for someone with dementia? How much water does your brain typically need to function optimally?

The answer is that there's no specific amount of water that someone with dementia should drink, or someone looking to prevent dementia should drink - but, as always, it's important to meet a regular hydration quota. This helps with brain function and the transportation of nutrients and oxygen in the blood around the body, including to the brain.

Water should be consumed continuously through the day, with

experts telling us that we should aim for:
  • Men - 2 litres per day
  • Women - 1.8 litres per day

Tap water, cognitive performance & dementia: Potential contaminants

As we've discussed, drinking water plays a crucial role in adopting a healthy lifestyle and minimising dementia risks and symptoms.

However, it's useful to be aware and have knowledge of contaminants that might be in your tap water supply, their significance, and how to protect yourself against any potential ill effects.

Tap water contaminants & their effects on brain health

Our water contains a range of common contaminants, such as chlorine, which can affect the taste, smell and sight of tap water - but are harmless on the whole.

However, the presence of heavy metals in drinking water has been implicated as a problem in neurological illnesses, including dementia. Heavy metals are not usually found in drinking water, but can leach in through old pipework, the main offender being lead.

One of the symptoms of heavy metal poisoning is a decline in brain function. In severe cases, this can lead to deteriorating dementia.

Another study in 2020 found that aluminium and fluoride in tap water was related to a later dementia risk. The research analysed those who lived in areas with higher levels of aluminium in water supplies against those who didn't. The author noted: 

"Higher levels of aluminium in particular are associated with an increased risk of dementia - Everybody included in the study was alive in 2005 and they were all born in 1921 - people who lived in areas with higher levels of aluminium in drinking water were more likely to die of dementia than those in areas where the aluminium levels were lower."

Dr. Tom Russ, Alzheimer Scotland Dementia Research Centre, University of Edinburgh. Lead author of Aluminium and fluoride in drinking water in relation to later dementia risk.

The UK has some of the finest tap water quality in the world. However, if you are concerned about fluoride in your tap water, or heavy metals leaching into your supply, investing in a water filtration system will maximise your efforts to live a healthier life.

Dementia prevention and alcohol

Consistent, excessive drinking of alcohol can place an individual at risk of alcohol-related brain damage, leading to a greater risk of dementia. If you drink heavily on a regular basis, you're more likely to have a reduced volume of white matter in the brain - the matter that transmits signals.

Therefore, it won't come as a surprise to learn that levels of alcohol consumption should be monitored for those looking to minimise dementia risk. The Alzheimer's Society recommend not exceeding these guidelines:

  • 1-14 units of alcohol per week for women
  • 1-21 units a week for men

A steady, healthy intake of water will help to prevent reaching for these less healthy fluid alternatives, whilst still being able to enjoy a drink if desired.

Start your water journey with Doulton®

Aside from the reduced chance of poorer brain function, optimal hydration and intake of water has innumerable other health benefits.

As discussed, our tap water can contain a range of contaminants which affect smell, sight and taste - and may even play a role in developing dementia.

At Doulton®, we've got over 180 years of experience producing a range of leading-edge ceramic water filtration products. We only settle for the best, and this philosophy is infused into all of our products. The result - great tasting, healthy filtered water.

Daniel Berko