Noise pollution linked to increased dementia risk

New US-based research published today (Wednesday 21 October) in Alzheimer’s and Dementia suggests those who lived in areas of higher noise pollution may be at an increased risk of developing dementia.

Which group of people did researchers look at?

Volunteers in the US over the age of 65 took memory and thinking tests every three years.

The researchers also estimated the noise 5,227 people experienced. They used recordings taken during the daytime and then factored in noise hot spots like traffic lights and busy roads.

What did the researchers find?

They found an increment of 10 decibels in sound intensity, roughly the noise of someone breathing, was linked to an increased likelihood of developing mild cognitive impairment (MCI) and Alzheimer’s disease.

Noise level was also associated with worsened ability to quickly compare or recognise symbols or figures.

However, noise level was not associated with a decline in memory and thinking over the study.

What did our expert say?

Dr Rosa Sancho, Head of Research at Alzheimer’s Research UK, said:
“There are nearly one million people in the UK living with dementia and it’s caused by devastating diseases.

“This new US-based research suggests a link between noisier areas to live and early-stage thinking problems, but if any causal link exists between these two factors, it is not confirmed by this study.

“The researchers estimated the noise levels someone experienced with readings taken during the daytime and during non-rush hour traffic, ten years ago in the US, so it’s difficult to say whether this research maps to the lives of people in the UK.

“Research has already implicated hearing loss in midlife as a risk factor for dementia and as the diseases causing dementia develop in the brain up to two decades before symptoms show, understanding what may be causing this link will be crucial for further research.

“While we can’t know from this study whether reducing noise pollution could reduce people’s dementia risk, policies to tackle this could have many other benefits for people living in noisy areas. For reducing dementia risk, the best current evidence indicates staying physically and mentally active, eating a healthy balanced diet, not smoking, drinking only within the recommended limits and keeping weight, cholesterol and blood pressure in check.”