Skip to main content
BlogFood & Health

Is drinking RO Water bad for us?

RO drinking waterThe importance of drinking enough water to stay hydrated and keep the body in top form cannot be understated. Tap, mineral, distilled, alkaline, spring, sparkling and RO (Reverse Osmosis)…these are common types of water available for drinking. These have gone through some form of treatment or purification to make it safe for drinking. Fortunately for Singaporeans, our tap water is safe to drink. However, this is not the case in many other countries where water contamination is quite high and hence water filtration systems especially RO water purifiers have been popular. But, in recent times the effectiveness of RO Water is being questioned, in fact risks have been identified regarding RO water consumption. Are these true? Is there a need to worry? Let us find out…

What is RO Water

RO water is water that has been filtered through reverse osmosis. But what exactly is reverse osmosis and how does it work?

Reverse osmosis is a water purification process that uses a semi-permeable membrane to filter out unwanted molecules and large particles such as contaminants and sediments like chlorine, salt, and dirt from drinking water. You may have learnt about this process in your science class. For RO drinking water, pressurized water is forced through a semi permeable membrane, removing pathogens and other impurities, leaving water clean on a molecular level. Unfortunately, essential minerals such as calcium and magnesium are also filtered out!

The use of RO water was initially restricted to laboratories and industries, however, due to a rise in water pollution in India and few other countries, the usage of RO water purification systems has extended out to homes.

On one hand you get almost pure water, but on the other its devoid of essential minerals. So, is it still safe to drink RO water? Let us look at some of the advantages and disadvantages of RO water.

Pros and cons of RO Water


  1. One of the best ways to soften hard water by removing hard minerals and sodium.
  2. Removes contaminants, microscopic organisms and hard metals such as iron, through special membrane filters.
  3. Improved taste of water and food cooked in RO water.


  1. Demineralization of water through filter membranes resulting in certain essential minerals like calcium, vit D and magnesium to be stripped off.
  2. Water becomes acidic.
  3. Takes a long time to filter the water.
  4. Contributes to water wastage.
  5. Can be costly to install.

Why some say RO water is not useful for health?

Although RO water removes impurities from our water, many people are sceptical to consume since the filtration process results in demineralization of water. According to this WHO study, “demineralised water that has not been remineralized is not considered ideal drinking water, and therefore, its regular consumption may not be providing adequate levels of some beneficial nutrients.”

RO water in a glassAlthough there are ways to remineralize water to a desirable mineral content, this is not considered optimum as the water does not contain all the beneficial components.

Read on to know about some of the health risks that may occur from drinking water with no or low mineral content.

Health Risks from Low-Mineral Water

Risk 1: Negative effect on Body’s Homeostasis

Homeostasis is the regulation of internal conditions inside cells or organisms, to create optimum conditions for cell function. Ingestion of distilled/ RO water leads to the dilution of the electrolytes dissolved in the body water. Drinking water with low TDS (total dissolved salts) has a negative effect on our body’s homeostasis. Low mineral intake, coupled with mineral loss through urinary excretion, results in further mineral imbalance. This causes a detrimental effect on hormone secretion, kidney functions, and bone mineral density.

Risk2: Loss of calcium, magnesium and other essential elements in food prepared in low-mineral water

The human body requires certain minerals and micronutrients for optimum functioning. Evidence has demonstrated that mineral elements from water are more readily absorbed in the body as compared to those from food sources. Ro water used for cooking causes substantial losses of all essential elements from food (vegetables, meat, cereals)

Risk 3: Kidney disease and gastrointestinal disease from acidic water

pH is the value that measures acidity or alkalinity of a solution where six to eight is neutral and lower values are considered acidic. Water obtained from RO filtration process has a low pH value. According to this site, prolonged consumption of low pH water has adverse health effects such as increasing the risk of kidney disorders and gastrointestinal troubles.

Antioxidant Alkaline Water vs RO Water

Fortunately, safer, and proven alternatives to RO water are available, one of them being antioxidant alkaline water.  Alkaline water has a higher pH level than regular water which can neutralize acids in the body. This lowers the oxidation reduction potential (ORP). The table below shows some of the differences between Alkaline and RO water

Alkaline Water RO Water
Does not require electricity Requires electricity
Enhances mineral content of water and adds electrolytes for better hydration Demineralizes water. Dilution of electrolytes hinders hydration.
Countertop filter does not waste water Pressure causes water wastage
Does not take up much space and is cost effective Filter units are large and costly
Enhances pH level of water Causes water to be more acidic


Knowing that the human body is up to 60% water, the type of water we drink is of utmost importance to reap maximum benefits. Water that is rich in essential minerals, that is easily absorbed by the body and keeps us hydrated is what the hand should reach out for. Thanks to the more safer and beneficial drinking water options, we can be sure of good, clean drinking water filled with desirable mineral content.

Stay Healthy, Choose AOX

For more information, contact us at
📮 PM: 9271 7505
☎️Call: 6715 9199
📩 E-mail:

× Enquire for Free Sample!