Although it contains no nutrients, water is vital to your diet. But the chances are you don’t drink nearly enough. Read on to find out why it’s time to get switched on to water - whether it’s bottled or from the tap.
If you haven’t drunk a glass of water in the past hour, take a good swig now. After oxygen, water is the most important thing you consume. You lose around half a pint a day simply through breathing. So you need regular top ups to replenish this and the water that’s lost in urine and sweat.
Water is integral to your health. About 85% of your brain, 80% of your blood and 70% of your muscle is water. Water removes toxins from the body, enables nutrients and oxygen to travel around it, cushions your joints, lubricates your eyes, and improves your skin tone. It also prevents fluid retention, banishes eye bags, and keeps your breath sweet.
Drinking too little water leads to dehydration, which can cause headaches, constipation and disrupt concentration. In older people such concentration dips can increase the risk off falls. A 1996 study published by the American Association of Cancer Research, suggested that drinking four to five glasses of water a day, rather than two or fewer, can reduce the risk of colon cancer by 45% in women and 32% in men.
Dehydration has also been linked to the rising levels of obesity in this country. This is partly because thirst is often mistaken for hunger, leading to more frequent snacks throughout the day, and partly because in the digestive process fat produces the most metabolic water when broken down. This can mean that you opt for fatty foods because they compensate for the lack of water in your body. If you’re on a diet, how much water you drink can affect your progress. Your kidneys can’t function properly without enough water. When this happens some of their work is transferred to the liver. One of the liver’s main functions is to metabolise stored fat into usable energy in the body. But if the liver is supporting the kidneys, it metabolises less fat, so more fat remains stored in the body hindering your weightloss efforts.
"Did you know that fresh fruit and vegetables have a high water content so you should eat more!”
How much water do you need?
You’re no doubt familiar with the mantra that you should drink two litres of water a day. But sonic experts say it’s not that simple and caution against a one-size-fits-all approach. Two litres could be too much for a woman who eats lots of vegetables and too little for a large man. How much you drink depends on everything from your weight to what you eat - 20% of your water intake comes from food; there’s more water in 100g tomato than 100g of fizzy cola.
To find your personal water needs, a health guru suggests the following: divide your weight in kilos by eight, round that figure up to the next whole number, and this will reveal how many glasses you should drink. Remember, this figure is your baseline. You’ll need to drink more during hot weather and if you’re exercising. Don’t forget it’s crucial to drink water before you hit the treadmill, and not just during and after exercise. If you don’t drink, it’s like heading our in your car with only three-quarters of a tank - you simply won’t go as far. To stay energised, drink about 500ml of water or a non-caffeinated drink spaced out over one or two hours before you exercise and another 200ml within 5 minutes of exercising.
What’s on tap?
Much tap water is recycled, so last night’s bath may cook tomorrow’s vegetables! British water quality regulations impose rigorous standards on our tap water. But although tap water is regularly tested, water supplies can contain a cocktail of ingredients some of which are there by accident. Certain pollutants, such as surplus agricultural nitrates and pesticides washed into the soil and back into the system along with industrial chemicals and poisonous metals may be present in minute quantities. And other chemicals are there by design to clean up the supply: chlorine (to kill bacteria), aluminium (as aluminium sulphate it is added to remove suspended matter) and fluoride (to reduce tooth decay).
Nitrates are particularly dangerous to babies and have been linked to some types of gastric cancer. In Britain nitrate levels are strictly monitored and are not allowed to exceed 50mg per litre. However, the permissible levels of nitrates in tap water is far lower than that commonly found in almost all food and is not regarded as a major risk.
Aluminium has been implicated in Alzheimer’s disease (and is still the subject of great debate). Fluoride, too, has been linked to a range of health problems including fluorosis; in areas where natural levels of fluoride in the water are high, children can develop a white mottling of teeth due to ‘overdosing’ on fluoride.
Lead is another contaminant that can affect your tap water. If your house was built before 1976, your home may be the source, because all or part of your pipe work is likely to be lead. If you can have them replaced, do. Meanwhile, always run the water for about half a minute before you drink it.
How to get enough water
Water is a major component of all drinks; carbonated and still drinks are 65% water, diluted squashes are 86% water and fruit juices are 90% water. But drinking plain water is still the best way to replenish lost fluids.
Start the day with a large glass of water when you wake. It’ll help to awake your thirst. If you’re at work keep a jug or bottle of fresh water on your desk, and top up your glass throughout the day.
If you’re out and about during the day; carry a bottle of water with you. Water is also in solid foods. Aim to eat more fresh fruit and vegetables; they have a high water content as well as other benefits.
All bottled up
In recent years, sales of bottled water have increased dramatically, with consumers who are still suspicious of tap water believing it to be the healthier option. But bottled water has no proven health benefits over tap water.
There are two types of bottled water: spring water and mineral water.
Spring water is collected straight from the spring and bottled at its source. UK spring waters must meet certain hygiene standards, and can be treated to ensure they meet the limits set on pollution.
Mineral water emerges from below ground, flowing over rocks before it’s collected, resulting in a higher mineral content. Unlike spring water it can’t be treated to remove grit and dirt. Different brands of mineral water will contain different levels of minerals depending on their source. But many mineral waters contain no more minerals than found in regular tap water. In 1999 new regulations were put in force by the government, which require the levels of minerals in natural mineral water to be listed on the pack - so always read the label if you want to be sure of what you’re drinking.
Always treat bottled water as a perishable food: don’t buy too much at once, drink it as soon as possible after opening, store it in the fridge and never drink any that has passed its sell-by-date.
Filter it out
If you’re fed up with scale in your kettle, oil-slick tea and water that smells like a swimming pool get yourself a jug water filter. They reduce scale and scum, remove the metallic taste, clear murkiness and discolouration and give you a cuppa that tastes like tea rather than chlorine. If you’re looking for a filter for health reasons, most jug water filters will reduce chlorine, copper iron, lead, aluminium, pesticides and some organic chemicals. But only a few will remove nitrates, and for these, you’ll need to dig deep into your pocket!
Whatever filter system you use, you need to replace the filter regularly, as directed by the manufacturer. Overuse your filter, and it will start to release the pollutants back into the water and breed bacteria. Some filters have built in warnings about when to change your filter. But a good rule of thumb is to replace the filter once a month. You should also wash the jug at least once a week with detergent and used filtered water straight away or refrigerate it.
Water treatment systems
If you find jug water filters a bit of a bother, take a look at one of the several types of automatic water treatment systems that give you filtered water straight from the tap. These include granular activated carbon filters, ceramic filters, reverse osmosis systems and distillers and on-tap filters. All with the exception of the last are plumbed into your mains water pipe under your sink and have a separate tap, so you have both filtered and unfiltered water. Water softeners might make good sense when it comes to preserving the life of your washing machine and boiler but they should not be used to produce drinking water. The softening agent used replaces the calcium and magnesium, responsible for making your water hard, with sodium. If you live in a hard-water area, keep one tap that supplies hard water for cooking and drinking to ensure you benefit from calcium.
• Don’t give bottled water to babies as it may contain unsafe amounts of nitrate or have a higher bacterial level than they can cope with.
• Don’t give them treated water unless the filter cartridge is fairly new and you boil the water as soon as it’s filtered.
• Do use boiled tap water for drinking water or your baby’s feed. But sterilise the container you use to store the water in or drink it from.