Water – the elixir of life

Did you know that our lungs are made up of 83 per cent water? To ensure we hydrate our bodies to their full potential Nutritionist Dr Emma Derbyshire explains why water is essential for our health and wellbeing…

Water is essential for life. It accounts for about 65 per cent of our body weight and performs crucial roles such as carrying nutrients and waste products between our major organs, helping regulate body temperature, lubricating our moving parts, and acting as a shock absorber.

The human body works hard to maintain optimal hydration by using hormones to control how much we urinate and giving our brains signals to tell us that we are thirsty. And because our brains are 75-85 per cent water, poor hydration can have an adverse effect on how our brains function.

On average, we take in and excrete around three litres of fluid a day but dehydration causes the following symptoms:

• Increased thirst

• Dry, sticky mouth

• Tiredness

• Reduced concentration

• Headache

• Muscle tiredness

• Decreased urine output

• Dark yellow or brown urine

• Dizziness or light-headedness In babies and young children, even mild dehydration can cause symptoms such as confusion, irritability and tiredness.

Young children are less effective at regulating their temperatures, and have a larger surface-to-weight ratio than adults so are less tolerant to fluid losses such as through vomiting or diarrhoea.

Our bodies are constantly fluctuating between different states of hydration. When our water intake matches our bodies’ requirements, this is described as optimal hydration.

Scientists, sports and health professionals sometimes measure hydration by measuring changes in body weight. Dehydration can be defined as a two to three per cent drop in body weight in a typical warm environment.

We are the greatest at risk of dehydration when we are too hot or too dry, have limited access to water, or need more water than usual. Warm or dry environments, such as centrally-heated homes or air-conditioned offices increase our need for fluid. We can lose additional fluid through sweating (due to exercise or hot climates), or by suffering vomiting and diarrhoea.

Like vitamins and minerals, our fluid requirements are individual and depend on factors such as body weight/size, physical activity and the temperature of our environment. However, a number of different expert bodies have made recommendations for fluid and these are a good starting point.

The Food Standards Agency has based its guidance on glasses of fluid a day (i.e. over and above any fluid that we may have from foods). Adults are recommended to drink six to eight glasses a day to prevent dehydration (around 1.2 litres).

Experts recognise that a regular intake of water is vital for maintaining good health. And optimal hydration can even help prevent some common conditions, such as constipation, urinary tract infections, gallstones and glaucoma.

It may also lower the risk of stroke and asthma. Emerging evidence also suggests that adequate hydration could play a role in the prevention of some cancers, including bladder and colon cancer.

Natural Hydration Council

 

How much water is in our body? Brain 75 per cent Lungs 83 per cent Liver 71 per cent Skin 64 per cent Bone 31 per cent Heart 73 per cent Muscles 79 per cent Kidneys 79 per cent Average water content is 65 per cent in adults