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The great water purification strength of reverse osmosis is one of the main reasons for people to use it.
However, it does have some downsides that are important to consider. Most importantly, reverse osmosis removes certain elements from water which would normally be beneficial to you: Minerals.
Does that mean reverse osmosis water also leaches minerals from your body? Let’s find out!
First of all, does RO water leach minerals from your body? Yes, RO water could leach minerals from your body.
How? Studies evaluated by researchers of the WHO suggest that if low-mineral water like distilled water or RO water is ingested, “the intestine has to add electrolytes to this water first, taking them from the body reserves”, so ingestion of such water likely “leads to the dilution of the electrolytes dissolved in the body water”.
In other words, drinking too much low-mineral water can cause your body to start expelling various minerals (faster) – including potassium, chloride, sodium, calcium, and magnesium. By how much? As far as we can tell, the WHO report did not quantify that.
Still, this makes it important to take a careful look at the mineral balance of your diet and make necessary adjustments, like taking supplements or adding a remineralization stage, if you plan on switching to low-mineral water exclusively.
Reverse osmosis strips minerals from water the same way it removes pretty much all other contaminants/impurities. It forces water through a thin membrane which only allows water molecules to pass through. Most minerals are too large to fit through the pores of that membrane. This means that they get removed along with all the bad stuff including lead, cadmium, chromium 6, mercury, asbestos, arsenic – you name it.
Reverse osmosis removes pretty much all minerals you can think of at high levels of effectiveness. Here is a brief list of some of the minerals targeted by the process:
You can generally expect a reverse osmosis filter to get rid of more than 96% of the mineral contents of your water.
Reverse osmosis works equally well against organic and inorganic minerals. There is nothing special about either type that makes them more or less susceptible to the process.
It doesn’t matter what types of impurities you’re dealing with in your water. You can rest assured that reverse osmosis will remove pretty much all of them.
The only inherent risk of reverse osmosis is drinking water with too few minerals which your diet could not compensate for. But generally speaking, drinking water contributes less than 5% of the daily required mineral intake of our diet – as long as it’s balanced.
Anyway, let’s consider some of the myths that surround RO water and see if they have any truth to them…
You might sometimes hear marketing materials referring to reverse osmosis water as “dead”. Do not be alarmed – that’s just a marketing trick. They say that because reverse osmosis water contains pretty much no minerals. However, that doesn’t make it inherently bad. Do not take the description as an indicator that there is something wrong with reverse osmosis water.
That’s simply not true. In fact, the World Health Organization recognizes reverse osmosis as an effective method for purifying water. The statements they have made regarding reverse osmosis water actually encouraged people to be more careful about monitoring the quality of their water and the operation of their filters. The WHO has never advised against drinking reverse osmosis water.
The actual recommendation issued by the WHO – which is probably the source of most people’s confusion – is to remineralize your water if you’re exclusively drinking low-mineral water. Specifically, they point towards calcium and magnesium as two minerals which should be replenished to some extent. According to the WHO, you should add at least 20-50 mg/l (ppm) of calcium and 10-30 mg/l (ppm) of magnesium to reverse osmosis water to balance it out.
This is also nonsense. This myth was likely started by people confusing the effects of reverse osmosis filtration with the effects of drinking reverse osmosis water itself. Simply put, there is no reliable scientific evidence that would suggest that reverse osmosis water will attack your body – what does that even mean?
The only thing that comes close to that is the fact that drinking too much low-mineral water can cause your body to expel certain minerals faster. Again, these include sodium, potassium, chloride, calcium, and magnesium.
If you’re concerned about the mineral contents of your reverse osmosis water, there are several options for remineralizing it.
A remineralization filter does exactly what its name implies. It adds minerals to water that passes through it. This can be added as a post-filtration stage after the reverse osmosis membrane. This is probably the most common approach to remineralizing reverse osmosis water. It’s not expensive and allows you to somewhat control how much you get of each mineral without the need to add them manually every time.
You can also use mineral-rich salts to compensate for some of the missing minerals from your diet. Simply use them in your cooking as you would normally do with regular salt. But make sure that you’re not consuming too much sodium, because you usually have to add a lot of salt in order to get a considerable amount of minerals.
You can use mineral drops directly in your water to enhance its mineral contents. This is convenient if you travel frequently. However, it might not be the most financially efficient approach.
There’s also the option of using an alkaline water pitcher. These filters have the added benefit of introducing minerals to your water. This approach might be a bit inconvenient, however. You have to take extra steps to additionally filter your water. If you live in a large household with many people drinking water regularly, this might not be the best idea.
With all that said, what exactly is reverse osmosis purification and how does it filter your water?
The process, as it turns out, is actually pretty simple in mechanical terms. The main component of a reverse osmosis system is a semipermeable membrane. The system forces water through that membrane at a high pressure. The small parts of the membrane only allow water molecules through (with some minor exceptions).
So when water passes through your reverse osmosis system, what’s left on the output side is clear, fresh water with no contaminants. All contaminants get mixed into the reject stream and are removed.
The main downside to reverse osmosis, other than the fact that it removes minerals, is that it can waste a lot of water.
If you have any questions about RO water mineral deficiency please don’t hesitate to leave a comment below!
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