Is mineral water worth drinking?

Water sustains all of life, so it is a subject that ought to be straightforward and crystal-clear, yet there’s so much confusion around it. Often, any bottled water is referred to as spring water, but that’s far from the truth. Equally, any sort of carbonated water, regardless of the means of carbonation, is often called mineral water, again often mistakenly. A few simple definitions may help:

• Spring water is groundwater that comes from an underground source (aquifer) and flows naturally to the earth’s surface.
• Tap water in Australia comes mainly from surface water stored in reservoirs. Only a small amount is from groundwater; other sources, such as desalinated seawater, are in the pipeline, so to speak, but will probably play an increasing role. New Zealand tap water is about 50/50 groundwater to surface water.
• Purified water is treated with processes, such as reverse osmosis, that remove dissolved solids, bacteria etc. Distilled and reverse-osmosis water has no minerals. Much of the bottled water we buy is nothing but expensive purified tap water.
• Mineral water is groundwater that is naturally high in mineral content derived from the rocks it flows over, so it varies from source to source. It is collected from springs or wells.
• Sparkling water has bubbles of carbon dioxide, either naturally occurring or artificially added. It may be sparkling mineral water, sparkling spring water or just plain sparkling water.

Naturally occurring mineral waters have been valued since ancient times. Traditionally, they were consumed at their source — known as “taking the waters” — but these days mineral water is almost universally bottled at the source and transported.

The main minerals are calcium, magnesium and potassium, and sometimes sodium, chromium, copper, zinc, iron, manganese, selenium and others, all of which are important for good health. According to mineralwaters.org, a non-profit consumer website, Australia produces 60 brands of mineral water and New Zealand 22. That’s out of around 3000 brands worldwide. We also import many European brands.

While some would argue that the amounts of minerals are too insignificant to matter much, studies suggest there are definite health benefits from drinking mineral water.

In 2011, a four-week controlled study led by Montana State University professor Dan Heil looked at the effect of mineral water on the body. People who drank alkaline mineral water from a river fed by glacial run-off, which had a water company’s supplement (designed to stabilise mineral and pH) added to it, were better hydrated and had higher pH levels. This was evidenced by reduced urine output and more alkaline blood and urine.

According to a review of studies published in Osteoporosis International in 2000, absorption of calcium from calcium-rich mineral water may be comparable to that from dairy products — or possibly better. This is good news for those who can’t tolerate dairy but want to maintain bone density.

Another study, published in the British Journal of Nutrition in 2005, found that drinking mineral water can reduce LDL (“bad”) cholesterol and increase HDL (“good”) cholesterol, helping to protect against cardiovascular disease. In addition, magnesium and potassium found in mineral water support healthy heart function.

Magnesium also helps to normalise blood pressure. In a study published in The Journal of Nutrition in 2008, subjects who suffered from hypertension and had low magnesium levels were given a litre of mineral water daily. Over time, they saw a drop in their blood pressure. Magnesium also helps to strengthen the immune system and relieve muscular pain and joint imflammation.

The sulphates present in mineral water aid digestion by stimulating the pancreas to release enzymes that help to digest food properly; similarly, the chlorides and bicarbonates in mineral water help digestion by balancing acid levels within the digestive tract.

Finally, studies have also shown that adequate amounts of magnesium and calcium in mineral water can lower the risk of kidney stones. These minerals decrease the concentrations of calcium oxalate that lead to the formation of kidney stones.

That’s an impressive array of pluses, so it would seem that the ancients and others of the past who travelled long distances to “take the waters” were on the right track. But that’s the thing: they travelled to the waters.

Now that the waters travel to us, mostly in plastic but preferably glass bottles, we can’t celebrate the health benefits of mineral water without acknowledging the elephant in the room: the environmental cost. Any bottled water has a very large carbon footprint. We need to weigh up the health positives against the environmental negatives.

There are times, though, when bottled water is the only choice and other times when a sparkling drink is a refreshing treat. So perhaps a balanced approach is to choose mineral or spring water when it’s necessary to drink bottled water, preferring those packaged and transported in the most environmentally responsible way, and enjoy a sparkling mineral water as a special beverage, as you would a glass of champagne.

Kerry Boyne is managing editor of WellBeing and Good Organic Gardening magazines and a regular contributor to both.