Humans can’t exist without an adequate intake of fluids. We can live for weeks without food, but only days without water. In some countries thousands are dying from dehydration, or because their water supplies are seriously contaminated. Most of us living in affluent Western countries have the good fortune of living in homes connected to a mains supply of crystal clear water. Nowadays this is sometimes treated as a second-grade commodity: fine for washing the car and hosing the garden but far too mundane for human consumption. Instead we’re joining the craze to spend our hard-earned cash on designer labelled bottles of natural mineral waters. In America, as many as a billion bottles of spa water are consumed every week, and in Britain the latest figures show that we’re now drinking about 300 million gallons of bottled water a year, with consumption rising at an annual rate of ten per cent. But even this is not enough to please the manufacturers, who are urging us to drink more spring waters to improve our health and avoid the risk of dehydration. According to the trade-funded Natural Mineral Water Information Service, nearly nine out of ten people in the UK are not drinking enough water to satisfy their biological needs. Earlier this year, to boost sales, the British Nutrition Foundation issued a press release saying that people could recover from the winter blues by drinking more fluids. No evidence was given to support this statement, nor did the Foundation think fit to mention that it’s financed by the producers of Evian, Volvic and Badoit bottled waters. The copy writer’s promise is that by drinking more we could improve our health. The public have clearly taken the message at its face value, for it’s now the vogue to walk around with a mobile phone in one hand and a bottle of Perrier water in the other. These are today’s comfort blankets, portable pacifiers which are sometimes even taken on theatre trips, so we can take soothing slurps to the annoyance of our neighbours whenever boredom sets in or tension levels mount. This is a needless waste of money, for while people complain about the cost of petrol, few realise that a gallon of Evian water retails at £20!
Is this obsessive quaffing really necessary? The average human being, doing light work in a moderate climate, loses roughly five pints of water a day. This is partly supplied in the food we eat, which can be up to eighty per cent water. More is delivered when the food is digested, since water is a normal by-product of food metabolism. This means that under normal circumstances our fluid needs are relatively small. This was confirmed by two kidney specialists at the University of Pennsylvania, writing in the Journal of the American Society of Nephrology, who said there was not a single study which proved it was a necessary to drink eight glasses of water a day. They also warned that there was a risk of drinking an excessive amount of water, which can have an adverse affect on the balance of salts in the body, leading to a potentially fatal condition known as ‘water intoxication’. Because of this risk, even marathon runners are now being warned to avoid drinking excessive amounts of water. You can have too much of a good thing. This was well known in the Elizabethan Age, when the East India Company regularly used ‘water intoxication’ as a form of torture. Anyone threatening their trading posts and colonial possessions in the Far East would be captured and force-filled with water until they capitulated.
In addition to the risks entailed in drinking unnecessary quantities of water, there’s also a danger in drinking bottled water, which is sometimes less pure than tap water. In 2003 researchers at the University of Wales College of Medicine carried out a study which suggested that around twelve per cent of food poisoning cases caused by Campylobacter infections are caused by drinking bottled water. A further problem is the wide variation in the mineral content of bottled waters. In one trial of forty-seven branded bottled waters, ten were found to be richer in calcium than the hardest tap water supplied anywhere in the British isles, some by as much as four hundred percent! For this reason, doctors now advise people with renal stones to avoid bottled waters with a high calcium content.
When New York suffered a heat wave in the summer of 2007 the city authorities urged people to shun bottled waters in favour of the local tap water which was described as ‘the champagne of municipal water.’ One of their key objectives was to reduce environmental waste, for four out of every five plastic bottles of spa water end up in landfill sites, since the bottles can’t be recycled and are non-biodegradable. A short while ago reporters from the ‘New Scientist’ magazine toured the world to see how local communities were responding to the call to lead a greener life style. My favourite of the twelve, inspirational examples they chose, was a small community in New South Wales, where the residents agreed to ban the sale of bottled water. Instead, they tapped into a local aquifer and now offer the local townsfolk the chance of filling their containers without charge from public water fountains. This not only overcomes the landfill problem, but also saves the oil that’s used to make the bottles. Massachusetts town has also imposed a ban on the sale of spa water, following a campaign led by an 82-year old activist who complained: ‘All these bottles are damaging our planet, causing clumps of garbage in the oceans that hurt fish and are creating more pollution on our streets.’
We should drink to quench our thirst. When the mouth is dry, or the urine a darker shade of yellow than usual, more water should be drunk. The body has an excellent regulatory mechanism, and keeps the body fluid levels constant within a one per cent range whatever the outside temperature, the level of work we’re doing or the water content of our food. This it does by varying thirst, changing the amount we sweat, and varying the amount of liquid voided through the lungs, urine and faeces. So the way to keep healthy is to listen to the promptings of your body rather than the admonitions of the food and drinks industry. Trust your instincts and you won’t go far wrong.
© Donald Norfolk 2010