But what is the consensus? Nothing really. Even experts are divided when it comes to this subject. I know doctors who will recommend distilled, purified water, and those who recommends mineral water. Both doctors will even give scientific papers to support their beliefs.
However, the scientific community did not release any official standing on this mater. We can only assume two things:  there were/are no complete and well-organized studies conducted to finally put an end to this debate; and/or  they do not want to kill the water bottling industry by endorsing a specific type of drinking water (which will become a political debate).
So, we the public are left to our own. What now? Well, here are some notes or snippets I collected in the Internet.
Is distilled or purified water enough?
Distilled/Purified, is water that has virtually all of its impurities as well as minerals and electrolytes stripped through distillation (boiling the water and re-condensing the steam into a clean container), leaving all contaminants behind. Distilled/Purified water is good clean water, unfortunately all the minerals and electrolytes are also all stripped out.
Distilled/Purified water tends to be slightly acidic moving your body to a less healthy state. Contributing your body to a condition prime for viruses, bacteria, and other menaces.
Dr. John Sorenson, a leading authority on minerals metabolism, said, “Minerals in drinking water are more easily and better absorbed than minerals from food.” Creating “healthy water” means removing harmful agents but keeping the beneficial minerals. Mineralize water is needed for all cellular functions and if there are no minerals in drinking water your body will strip the minerals from somewhere else in your body to satisfy its need. While mineral water has many great benefits, not all mineral water are alike or has the same benefits. It’s wise to consider before purchasing mineral water is the content of what minerals are available in the drink and it absorbability.
Now as to the argument that distilled water leaches out minerals. This is true, and this is exactly what we want it to do. The minerals it leaches out are of the unusable, ionic form and we want these to leave the body rather than be deposited and cause disease. Distilled water does not leach out significant amounts of biologically available minerals because these are quickly taken up by the body on an as needed basis. If they are present in excess then they are filtered through the kidneys and this is exactly what needs to happen with all things which are in excess in the circulation. Distilled water cleanses the body through promoting healthy kidney function.
Finally, if mineral water is not a good source of biologically available minerals, then what is? Think about it. Minerals are present in the ground and must be biologically bound in order to be used by the body. Where would that come from? Plants, of course! Your mineral source should be plants not water. The purpose of water is to cleanse the body. To do the best job of that, it must be free of everything else. Only distilled water fits that bill.
~ Dr. Ron Kennedy, M.D., Santa Rosa, CA
3. Mineral waters. Again, water is water and most bottled varieties will rehydrate the body effectively. Mineral water can come from a natural well or spring, but must contain a specified amount of trace minerals. These minerals, such as calcium and magnesium, are essential for good health. There is no difference between sparkling and non-sparkling mineral waters except for the concentration of carbon dioxide. Both varieties contain a higher concentration of minerals than either spring or well water. Because the water must meet specific requirements, the number of water sources that qualify is very limited. Most of the popular varieties of mineral waters are bottled in Europe and imported to the United States. This means that bottled mineral water is going to be more expensive than other types, but the benefits of the added minerals are measurable. Mineral water may be more of a treat than a daily refreshment, but it does offer some health benefits. Some may find the taste to be harsher than traditional water, but many bottlers offer flavored varieties that may be more palatable.
4. Distilled water. Distillation is a process by which water is boiled until vapor is produced. This vapor is collected and cooled until it returns to a liquid state. Because minerals are too heavy to be carried by the vapor, the resulting water is completely free of additives. A desalination plant is a perfect example of distillation- salt water is boild, the vapor is cooled and collected, and the salt and minerals are left behind. However, distilled water is also very unpalatable in its natural state. Desalination plants must also add some minerals in order to make the water usable for general consumers.
Distilled water is perfect for applications where minerals and contaminants would cause problems. Distilled water can be used in irons for steam settings or as coolant for car engines. Because there are no minerals that can stain or build up, distilled water is mostly recommended for use in machinery and cleaning products. It is not particular good to drink distilled water, because it has a tendency to pull minerals out of the bloodstream and other areas. Distilled water is perhaps the cleanest version of bottled water available, but it is not good for human consumption.
Fasting using distilled water can be dangerous because of the rapid loss of electrolytes (sodium, potassium, chloride) and trace minerals like magnesium, deficiencies of which can cause heart beat irregularities and high blood pressure. Cooking foods in distilled water pulls the minerals out of them and lowers their nutrient value.
Distilled water is an active absorber and when it comes into contact with air, it absorbs carbon dioxide, making it acidic. The more distilled water a person drinks, the higher the body acidity becomes.
According to the U.S. Environmental Protection Agency, “Distilled water, being essentially mineral-free, is very aggressive, in that it tends to dissolve substances with which it is in contact. Notably, a carbon dioxide from the air is rapidly absorbed, making the water acidic and even more aggressive. Many metals are dissolved by distilled water.”
The most toxic commercial beverages that people consume (i.e. cola beverages and other soft drinks) are made from distilled water. Studies have consistently shown that heavy consumers of soft drinks (with or without sugar) spill huge amounts of calcium, magnesium and other trace minerals into the urine.
The more mineral loss, the greater the risk for osteoporosis, osteoarthritis, hypothyroidism, coronary artery disease, high blood pressure and a long list of degenerative diseases generally associated with premature aging.
Confusing? Yes. The next question is, what is the alternative?
The choice to be made is simply which product produces the healthiest water and represents the best value. Quality home water filtration can offer significantly purer water than tap or bottled water.
The source of the quote above even have this to say:
From a non-scientific perspective, the simple fact that nowhere on this planet do we find naturally occurring de-mineralized water, should tell us that we were not meant to have it. In nature all fresh water contains traces of natural minerals like calcium, magnesium and potassium, which is what our body was designed to run on and what the Aquasana system produces.
On a more scientific level, there are several very credible research reports and books that stress the more recent opinion that long term consumption of de-mineralized water can in fact be dangerous. Dr. Zolton Rona, author of The Joy of Health, states that “the longer one consumes distilled water, the more likely the development of mineral deficiencies and an acid state.” Dr. Paavo Airola, cancer expert and author of “How to Get Well” and “Cancer… Causes, Prevention and Healing” also reports that “long term consumption of distilled water eventually results in multiple mineral deficiencies.”
Two very negative things happen when we consume water that has been stripped of its natural minerals. First, because de-mineralized water contains more hydrogen it is an acid with a pH below seven. Any time we consume an acid substance our body will pull minerals from our teeth and bones to produce bicarbonate in order to neutralize the acid. Second, it has been proven that when our body fluids become more acid than alkaline the production of free radicals increases, causing increased cancer risks. Many studies suggest that cancer cells can only grow in an acid environment. This theory seems to be supported by the fact that around the world the areas where people live the longest most disease free lives are the areas that have the most alkaline water, water with the highest mineral content.
From this, we can safely conclude that our bodies were designed to drink mineral water, and it is poison to us if we drink distilled or purified water unless necessary, say, doctor’s prescription because of some complications. In the end, it all comes down to you. Do you want to live longer or shorter? Do you have to live more healthier or less healthier? Then begin by choosing between distilled/purified (which includes soda) versus mineral water.
First image – Zen Water by darkpatator is licensed under CC By 2.0.
Second image – The World of Water by Snap is licensed under CC By 2.0.