Is there a link between tap water and dementia? New research warns millions in the UK could be at risk

• Drinking tap water could increase the risk of dementia - a new study has claimed.
• Scientists claim that soft water can have a ‘harmful effect’ on “neurodevelopmental disorders”, including dementia and multiple sclerosis.
• Their study suggests that people exposed to soft to moderately hard water have a higher risk of developing vascular dementia.

Drinking tap water could increase the risk of dementia, new research has claimed.

The study is said to be the first of its kind to investigate the link between water and neurodevelopmental disorders. Scientists investigated the “associations of water hardness with neurodegenerative diseases”.

Their findings suggest soft water has a “harmful effect” on “neurodevelopmental disorders”, including dementia and multiple sclerosis.

Areas in the UK that have soft water include Scotland, Northern Ireland, most of Yorkshire, Cornwall and the west and south coast of Wales - with millions of people living in those areas.

Based on data from nearly 400,000 people in the UK, the research was carried out by a team of scientists from China and Imperial College London.

The authors of the study said: “Our study proposes the role of water with low mineral content as a relevant risk factor for neurodevelopmental disorders through long-term and accumulative exposure, strengthening and complementing the human health effect of water hardness.

“We provide new evidence about the harmful effect of soft water on neurodevelopmental disorders that highlight the importance of optimising water quality standards to ensure long-term health benefits.”

Talking to us about the new study, Awadhesh Jha, Professor of Genetic Toxicology and Ecotoxicology at the University of Plymouth explained: “This is an interesting study. Biological systems and functioning of human bodies are however quite versatile, adaptive, and resilient. Our response to environmental factors including lifestyle (e.g. smoking or drinking) qualities of air, food or water depend on our genetic make-up or the genes we inherit.”

Professor Jha added: “Based on the study and the results obtained, the assumptions suggesting a correlation with water softness leading to neuropathological conditions is farfetched and the conclusions drawn are premature.

“The study does not provide any real mechanistic explanation for the role of Calcium (Ca) and Magnesium (Mg) in the development of such neuropathological condition.

“The authors only make shallow speculations regarding role of physical activity and inflammatory processes and their role in the development of these conditions. Control studies with homogenous population or animal models are required to confirm the conclusions.”

Regarding recommendations in the study to maintain water hardness, Professor Jha said they had “gone too far”.

He added: “It will be a challenging task for the water industries for which the consumers will have to ultimately pay.”

Sign up for our UK Today newsletter - delivered daily

What is dementia?

Dementia is a syndrome associated with an ongoing decline in brain function, common early symptoms of dementia can include:

• emotional changes such as irritability
• forgetfulness
• struggling to follow a conversation or find the right word
• being confused about time and places

England has one of the highest dementia diagnosis rates in the world, with research showing that in the UK one in 11 people over the age of 65 have dementia.

You can find out more information about dementia at NHS.UK.