Nine myths about drinking distilled water

Written by William Fryer - MA Oxon

There's a lot of misinformation around about drinking distilled water. This document sets out the facts...

A lot of our customers research distilled water in various forums and Facebook groups on the Internet and there are a number of myths about drinking distilled water which are untrue and have no scientific basis. This document sets out the scientific facts.


Distilled water is an active absorber and absorbs carbon dioxide on contact with air, making it acidic. The acidity can then leach minerals from the body.

THE FACTS: This is true but it is nothing to worry about. Pure H2O does weakly bond with CO2 to form Carbonic Acid. That is why both rain water (which is distilled water) and distilled water are mildly acidic. But not enough to harm you at all, we're talking pH5 or 6. That is about the same as a banana. Neutral pH is 7. Your stomach has a pH of 1-2. The pH scale is logarithmic that means pH6 is ten times more acidic than ph7. So distilled water, after contact with air, is 10-100 times more acidic than neutral (if that makes sense). Your stomach is 1000 times more acidic than distilled water. And Coca-Cola with a pH of 2.8 is over 100 times more acidic than distilled water. The idea of acidic water sounds scary but it does not harm you, if it could, rainwater would harm you and most foods would harm you. There is nothing harmful about drinking distilled water. And if you are at all worried about it being mildly acidic then you can always add a pinch of Sodium Bicarbonate.

The whole leaching minerals argument is an example of what is called psychologists call truthiness; it kind of sounds like it could be true so people believe it. In reality it is non-science. Your body works extremely hard to keep your blood pH between 7.35 and 7.45. If it goes outside that range then your enzymes start to denature and you need to go to hospital. Even people who are slightly out of range like pH7.25 can be very ill indeed. For your blood to be acidic enough to actually start leaching minerals it would have to be well below pH6 and you would definitely be long dead by then.


Cooking foods in distilled water pulls the minerals out of them and lowers their nutrient value.

THE FACTS: Cooking any foods lowers the nutrient value, especially when cooking in water and draining the water. Steaming is better. But your food will be less contaminated if you cook it in pure distilled water. Distilled water is no more "leaching" than any other type of water. The heat is more of a problem than the water used because heat can alter nutrients. Basically if you want to preserve maximum nutrient value in your vegetables steam them - using distilled water will not have any especially adverse effect on the nutrient content of your veg.


The most toxic soft drinks that people consume (i.e. cola beverages and other soft drinks) are made from distilled water.

THE FACTS: Certainly Coca-Cola is not made from distilled water. There is no economic reason why a soft drink manufacturer would want to spend time and money distilling water to make soft drinks. It puts up their cost per litre. Even if soft drinks were made from distilled water it is the sugar and other additives that are the problem; distilled water would only make them healthier. SMART water the bottled water brand owned by Coca-Cola corporation is basically distilled water with a bit of salt added into it. You can make your own "SMART" water at home using a distiller for about one tenth of the cost of bottled SMART water.


Distilled water causes mineral deficiencies because it lacks the minerals found in other types of water.

THE FACTS: Yes distilled water lacks minerals, No it does not call mineral deficiencies. Even mineral water has so few minerals in it, you could not depend on it as a dietary mineral source. We get minerals from food, not water. Distilled water does not leach minerals from your body. Naval sailors have been drinking distilled water for years without any ill effects. Development agencies supply water distillers as water purifiers to people in the developing world. Below is a table showing the the minerals you need, how much you get in a litre of Evian and finally how much Evian you would need to consume to get your daily amount. There is nothing special about the mineral content of Evian, we have just selected it because it is well-known. The average bath hold about 150 litres of water, so I have listed the number of baths you would need to drink each day for the higher quantities.

Table. 1. Distilled Water and Mineral Requirements
Mineral How much is in 1L of Evian How much you need each day How much water you'd need to drink
Calcium 76mg/L 700mg 9 litres
Potassium 1.1mg/L 3500mg 3182 litres  or (c.21 baths)
Magnesium 25mg/L 270mg 11 litres
Sodium 6.8mg/L 6g 882 litres or (c.6 baths)

If you think you are capable of drinking 21 baths full of Evian every day just to meet your Potassium requirements please be my guest. Drinking that much water would actually kill you (if you could get it down). As the table shows mineral water is just not viable as a source of minerals. You get vitamins and minerals from food. Also, a lot of these minerals - especially Calcium and Sodium are those which most people consume too much of. If anything you need to do what you can to reduce your intake especially of Sodium.


Drinking distilled water for long periods of time weakens your teeth.

THE FACTS: This is a lie invented by water filter salespeople to help them sell water filters. Water distillers do remove fluoride from water but there is plenty of fluoride in toothpaste if you want fluoride. Excessive fluoride can discolour teeth and has been linked to cancers. Fortunately not that many areas of the UK actually fluoridate water. I also object in principle to the idea of a government medicating a nation via the water supply. It violates a personal liberty. Water distillers remove any flouride present in water and that's a good thing.


Distilled water tastes "funny" or has a "flat taste".

THE FACTS: Distilled water definitely tastes different to ordinary tap water. Tap water has fluoride, chlorine, iron and other chemicals and your taste-buds get used to it. The first time you drink distilled water it will taste different. Although most people do not experience it tasting flat. Sometimes it takes a couple of days to get used to drinking distilled water. What is really interesting is how bad ordinary tap water tastes after you have been drinking distilled water. Personally the way I view this is like your taste buds get used to drinking tap water with all the chemicals in. Then you drink distilled water for a few days and it kind of resets your tastebuds. When you later drink ordinary tap water you suddenly get to taste all the chemicals that are present.

If you only distil your water, volatile organic compounds (VOCs) and some dissolved gases can be carried over into the distilled water. That is why Megahome distillers use charcoal filters to remove VOCs and gases. VOCs are chemicals like herbicides, fuels, etc which have a boiling point lower than water.

In general when used for cooking and drinking water, most people find distilled water improves the taste of food and is more thirst-quenching than tap water.
For a tiny minority of people it takes a couple of days to get used to and after that ordinary tap water starts tasting flat and almost "furry".


Distillation does not remove Volatile Organic Compounds (VOCs).

The FACTS: There is some truth in this. VOCs are organic compounds that have a lower boiling point than water. VOCs are chemicals like as pesticides, herbicides and fuels - so you do want to remove them. When water is boiled in the boiling chamber any VOCs present will get carried over into the cooled distilled water so VOCs are the one class of chemicals that distillation does not remove. For this reason Megahome water distillers come with an activated charcoal filter for the final stage of the process. The activated charcoal filter removes the VOCs present.  VOCs have quite a strong influence on taste and which is another reason to remove them (aside from the health risks posed by substances like organophosphates.) If you are from an area with potentially high VOC contamination you can double up on the charcoal filters.


Distillation systems require extensive, frequent cleaning and are difficult to operate.

THE FACTS. Depending on where you live, your distiller will need regular cleaning. But all you have to do is lift off the top and use the cleaner provided to dissolve any scale build-up. People in hard water areas will have more cleaning to do. Most people do a quick wipe around after each distillation. Our distillers are easy to operate. Just fill it up, press the button once, walk away and come back when it has finished. Yes it will need a quick wipe around each time but it is definitely not difficult to operate, and if you give it a good wipe after each distillation you will minimise the time spent doing a more rigorous clean. Also, if you do need to do a full clean you simply fill the boiling vessel, put in a few spoonfuls of cleaner and heat it up for a while. All the limescale just dissolves with the cleaner. It is not hard work at all.


Producing distilled water is expensive and uses lots of electricity.

The FACTS: Distillers do use electricity to produce pure water. A typical home water distiller uses around 3 kilowatt hours to make 4 litres of water. Using an average electricity cost of 12p per kilowatt hour, 4 litres of distilled water would cost about 9p per litre. This is cheaper, purer and more convenient than bottled water.


Drinking distilled water for a long time may kill you.

Can distilled water kill you? No it cannot. Some say that drinking distilled water alone, for a long period of time can kill you due to the lack of minerals in distilled water. Firstly, you can't just drink water to survive, you need food. No water, not even mineral water such as Evian, has enough minerals to provide what our body needs. To get enough Sodium from Evian, you would need to drink 882 litres a day. You can get the vitamins and minerals from your daily diet. Read more about minerals and distilled water here

If you want to buy one of our water distillers click here.

Author Bio

William Fryer MA Oxon
William is a Human Scientist and director of Having worked for 22 years in the corporate environment he is now studying a medical degree. His interests include: human beings, white water kayaking and walking in rugged environments.

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