The health risks of demineralised water

Reverse osmosis is a water purification process that is effective in removing a large amount of contaminants in water such as bacteria, dissolved salts, and many others. However, the process also removes many essential minerals that are key to good health. The focus on the removal of toxic contaminants in unpurified water and controlling it has led to the neglect of essential minerals.

Scientist Frantisek Kozisek from the National Institute of Public Health in the Czech Republic wrote in a World Health Organisation (WHO) report that consumption demineralised water may hold several health risks. He asserts in his paper that drinking water should contain minimum levels of essential minerals and carbonates.

Ramesh Kumar Sharma in a paper published in 2017, suggests that minimum limits must be set for certain important minerals that dieticians and nutritionists consider important for the functioning of the human body such as copper, calcium, magnesium, iron, selenium, and many others. Kozisek further says that, almost none of the commonly used methods to remineralise water after purification can be considered adequate to provide any health benefits.

Bengaluru's water a deadly drink

Other studies that were published in the WHO report show evidence to support the assertion that low-mineral water or demineralised water can pose many health hazards including higher risk of cardio-vascular disease, motor-neuron disease, increase in risk of pregnancy disorders and even some types of cancer he says quoting evidence from various studies. Water low in calcium can also be associated with neurodegenerative diseases and higher risk of fracture in children, the paper says.

We are looking away from the crisis

A study by Ekant Surendra Gupta, Sanket Pranjivan Sheth, and Jaishree Deepak Ganjiwale published in the Journal of Clinical and Diagnostic Research in 2016 concludes that there is a positive correlation between vitamin B12 deficiency and drinking demineralised water processed using reverse osmosis. Vitamin B12 is essential in making red-blood cells and and lack of it can lead to anemia.

What is Reverse osmosis (RO) system?

Many research studies have found a causal relationship between drinking demineralised water, a product of the reverse osmosis process and various health risks. Though high quantities of the minerals can be harmful, low quantities or lack of these minerals is not great news for one’s health either. A balanced quantity of essential minerals is not found in the water filtered using the reverse osmosis process and hence can pose health risks. Remineralisation of RO water purified may seem to solve the issue but due to issues with the remineralisation process as Kozisek says, it may not be very useful either.