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Is mineral water really so good for you?

Liz Bestic discovers that copious amounts of bottled water may not be essential to the body, while Lucy Mines puts a selection to the taste test

THE past few years have seen a growing interest in the benefits of drinking bottled water, with most health "gurus" encouraging us to drink at least two and a half litres a day. But is there any evidence to support their claims, or are we just blindly believing propaganda put out by mineral water companies eager to expand profits?

If you believe David Oliveira, professor of renal medicine at St George's Hospital, Tooting, there is nothing magical about drinking water - mineral or otherwise. Prof Oliveira happily admits to hardly touching the stuff. "My fluid intake is strictly confined to coffee, tea and the occasional alcoholic beverage and fruit juice.

"That doesn't mean I am unhealthy. The kidneys are pretty amazing organs and how fluid is generated in the body is totally irrelevant to them. When fluid arrives in the gut, it gets absorbed as water, so the bloodstream doesn't care whether the fluid started out as water, or tea, or coffee. By the time it gets to the kidneys, they don't know any better, so it really is a myth that you need to drink litres of water," he says.

The myth seems to have come about because we are made up of so much water - between 45 and 65 per cent. It seems only common sense that some water is vital for our health and wellbeing. Not only does it lubricate our joints and eyeballs, but it cushions our nervous system and helps us to swallow. Without it we could not regulate our body temperature through sweat - and we are continuously losing water through urine and faeces, our skin and lungs.

The good news is that you don't have to drink litres of water; there are plenty of other good sources of fluid.

"Fruit and vegetables, soups and casseroles - even meat - all contain plenty of water," says Prof Oliveira. Nor do you need to struggle back from the supermarket with mineral water - tap water is fine; if you are worried about chemicals, get a water filter.

But what about all the mysterious toxins? "There is a lot of mumbo jumbo talked about these toxins," says Prof Oliveira. "The kidneys are extremely efficient at getting rid of any poisons in the body, but they can manage to do that in just half a litre of urine. They certainly don't need two and a half litres and definitely not in the form of pure water," he adds.

Of course, drink too little fluid and you can get into trouble. Lethargy, headaches and lack of energy can mean we need to drink more.

A recent study of primary school children showed that those who drank water throughout the day stayed more alert during lessons and performed better at certain tasks. The British Dietetic Association (BDA) believes children are a special case. "Children are more likely to get overheated from strenuous exercise than adults," says Dr Wendy Doyle, from the BDA. "They don't perspire as much as adults and teenagers, so their body's 'air conditioning' is less effective and they need to be encouraged to drink enough fluids before, during, and after any physical activity."

The BDA recommends between 1.5 and 2 litres of fluid a day and suggests this should include some water. "However, other drinks such as tea, coffee, fizzy drinks and fruit juices also make a difference," says Dr Doyle. To gauge individual needs, you need to take a number of factors into account, including the weather, how active someone is, and whether or not they are doing strenuous work.

"All of these things have a part to play, so that figure is really only a guide. The best way to gauge how much is right for you is to listen to your body and drink fluids according to how thirsty you feel."

Prof Oliveira agrees. "As long as we drink when we feel thirsty, we are responding to a very basic signal from our bodies. Thirst is a sign that the blood is starting to become a little bit too concentrated, and when that happens, we have something called the 'thirst mechanism' which immediately kicks in and lets us know when we need to drink more."

Continuous signals tell us when to drink more or excrete extra fluid in order to maintain the correct balance in the body. "It's an extremely finely balanced and very powerful system - you only have to get slightly dehydrated to become intensely thirsty and it is almost impossible to resist," he adds.

Alcohol dehydration is a different story. "As a rough guide, for every 1ml of alcohol drunk, 10ml of fluid is lost in urine. That means that for every glass of wine, you may gain about 125ml of fluid, but you will lose 150ml. So top up your water glass if you are on a heavy night out," he says.

As we know from horror stories about young people and ecstasy, it is also possible to drink too much water. Although rare, you can get water intoxication. However, that means drinking such a huge amount - a minimum of three litres - that the blood becomes over-diluted. The cells of the body swell up and symptoms include drowsiness, a feeling of weakness or sometimes convulsions.

"Occasionally, people with schizophrenia who have delusions about parasitic worms roaming around their body, drink vast amounts of water to try and flush out these imaginary creatures. They do get into trouble. But those are the extreme cases. It really is almost impossible to force down 10 or 15 litres of water."

Athletes and other active people need to replace the fluids lost through perspiration. Athletes can sweat out more than two quarts of fluid per hour and for every pound of water lost during exercise in sweat, an additional two cups of water need to be taken in.

Some medical conditions require patients to drink several litres of water a day. Kidney stones or urinary tract infections are two examples.

Recent research backs this up. "Fluid consumption can reduce the risk of urinary stone disease, cancer of the colon, childhood and adolescent obesity, salivary gland malfunction and it can improve your overall health if you are elderly," says Dr Doyle. "A simple way to check that you are drinking enough fluids is the colour of your urine. The more transparent it is, the more hydrated you are. The darker it is, the more concentrated and therefore the more dehydrated you have become," she says.

"Early signs of dehydration include headaches, fatigue, loss of appetite, flushed skin, heat intolerance and a dry mouth and eyes. That's when you really know you need to get to a tap."

The clear favourites

Being asked to test the difference in taste between bottles of mineral water sounded bizarre - after all, water is supposed to be tasteless. Nevertheless, to my surprise, there were clear differences. I am no connoisseur - before the test, I would buy a bottle of water and drink it without even thinking about the brand. But the aim of the exercise was to distinguish whether each water had a distinct taste. To ensure that I was sampling the true flavour, I used odourless plastic glasses.

Still water

Evian (French)

It seems this is everyone's favourite and with its lightness and balanced composition, I can understand why. It is very pure and has a low mineral content, which means it can be given to babies.

Vittel (French)

Vittel has the same clean, clear taste as Evian. It also has a low mineral level, with a well-balanced supply of minerals and trace elements. Claims to be good for maintaining and restoring vitality.

Brecon Carreg (Welsh)

Another water low in minerals that was enjoyable to drink, with a refreshing and pure taste. It tasted naturally clean, as if it had been channelled directly from a stream, straight into a bottle.

Ballygowan (Irish)

I have often drunk this water but, after sampling the three previous offerings, I was surprised. It tastes quite sharp and metallic, even "processed". Ballygowan has a naturally high calcium content, making it a good source of minerals, but I thought that did affect the taste.

Ashe Park (English)

Ashe Park is very similar to Evian in mineral content and flavour, with the same clean, crisp, pure taste.

Spa Water (Belgium)

My immediate reaction on swallowing this water was "ugh". It was not refreshing in the slightest, and seemed to leave an aftertaste In fact, it reminded me of rather soapy bathwater.

Aqua Pura (English)

This water did not taste very refreshing. It was actually similar to rain water, leaving an unpleasant taste in my mouth.

Volvic (French)

Volvic is similar to Evian - light and mild tasting. It has a low mineral content and contains rare trace elements. Volvic water is well balanced, with a neutral pH, and is neither hard nor sharp-tasting.

Deeside (Scottish)

Deeside has been called one of the purest waters in the world. It is apparently unique, with a long history of health-giving properties due to its low mineral content. However, I found it similar to Ballygowan - the taste was metallic and rocky.

Abbeywell (English)

This was very refreshing, similar to Evian and Vittel in taste and mineral content; it was clean and pure with no aftertaste.

Danone Activ (French)

Sorry, but it was disgusting. It tasted like a glass of very milky water. Almost as soon as the water enters your mouth, your teeth and mouth feel chalky. But to be fair, those who can gulp down a glass of milk quite happily without a second thought, would most probably love the extra calcium.

Sparkling water

Highland Spring (Scottish)

Highland Spring is classed as low in minerals, which is reflected in the taste, making it pleasant and refreshing, even snow-like.

Ashe Park - slightly sparkling (English)

Not "slightly sparkling" - very sparkling. Despite being carbonated, it did have a rather pleasant, sweet taste.

Ashe Park - sparkling (English)

Knowing the fizziness of the slightly sparkling variety of Ashe Park, I was prepared for my head to be blown away with this one. It nearly was. Be warned it is very fizzy, making it, for me, unpleasant and quite undrinkable.

Aqua Pura (English)

The level of fizziness was manageable but it tasted of chemicals, which left an unpleasant taste - similar to the still variety of Aqua Pura.

Abbeywell (English)

I enjoyed drinking still Abbeywell, so was interested to see what the sparkling form would taste like - but it was quite disappointing. It was very sparkling, the bubbles felt as if they were exploding in my mouth. Not a very pleasant taste, rather salty.

Spa sparkling (Belgium)

I was not expecting too much from this water, especially after trying Spa Still. My worst suspicions were confirmed. It tasted very metallic, with a distinct aftertaste.

Brecon Carreg (Welsh)

This water was pleasantly fizzy and very similar to Ashe Park in that it tasted sweet. I would even compare it to bland lemonade.

Perrier (French)

This has to be the Evian of sparkling bottled waters. It is fortified with gas from the source, making the bubbles natural. It quenches the thirst, it is not offensive and is a lot less gaseous than many of the others.

The verdict

For a sparkling water, I would go for Perrier: the taste is plain, not metallic and it does not leave one feeling about to explode.

As for still water, the obvious choice would be Evian. AbbeyWell and Brecon Carreg also scored well: they were refreshing, pure and clean, with no lingering aftertaste.

-- Anonymous, April 23, 2001