By Jakob Haugaard Christiansen 

Exposure to noise from a nearby road or railway for an extended period can lead to a significantly higher risk of developing dementia. And the higher the noise, the greater the risk, according to Danish researchers.

A breakthrough project with researchers from the University of Southern Denmark, Roskilde University, Odense University Hospital, and the University of Copenhagen demonstrates a clear connection between noise and dementia diseases such as Alzheimer's.

The Danish research results were published Thursday September 9th in the renowned British Medical Journal, and the study shows that you have a 27 percent increased risk of developing Alzheimer's and an 18 percent increased risk of developing dementia in general when exposed to traffic noise above 55 decibels for an extended period.

Noise is harmful
- The results are surprising since it's the first time we have established a clear connection between traffic noise and the development of dementia, says Manuella Lech Cantuaria, ph.d. at the Mærsk McKinney-Møller Institute at the University of Southern Denmark.

She hopes the results can pave the way for further research in the field to benefit public health.

- We want to increase the focus on the health risks associated with being exposed to noise, which is not only an annoyance but also harmful to your health. Hopefully, our results can help influence urban development. The results should be considered in noise regulation programs such as highway shielding and noise-reducing asphalt, says Manuella Lech Cantuaria.

Great potential in preventing dementia
According to Jesper Hvass Schmidt, who is a chief physician at Odense University Hospital, stress and poor sleep are part of the problem. 

- The noise stresses the body, which triggers poor sleep. It creates fatigue, which in turn triggers more stress and increases the risk of developing dementia. Research results like these are essential because they indicate that noise is a public health problem, he says.

At Roskilde University, adjunct professor Mette Sørensen, an expert in traffic noise, emphasizes that the results from the three-year project can pave the way for even more much-needed research in the field.

- Our result potentially gives us completely new opportunities to prevent dementia, she says.