A new study from Denmark has identified a link between traffic noise and a greater risk of dementia. The experts found that road traffic and railway noise were associated with a higher risk of Alzheimer’s disease of up to 27 percent.
Of the 8,475 cases of dementia that were registered in Denmark in 2017, the researchers estimate that 1,216 cases could be attributed to traffic noise exposure.
The results of the study indicate that reducing traffic noise has great potential to combat dementia. Previous research has linked traffic noise to a range of other health conditions, including coronary heart disease, obesity, and diabetes.
For the current investigation, the researchers looked at the association between long term residential exposure to road traffic and railway noise and the risk of dementia among two million adults over the age 60 who lived in Denmark between 2004 and 2017.
After accounting for other factors, the experts found that an average of 10 years of exposure to road traffic and railway noise at the most exposed sides of buildings was associated with a higher risk of all-cause dementia.
The effect of noise on health may be explained by sleep disturbance and the release of stress hormones, which could lead to inflammation and changes in the immune system – early events in the onset of dementia and Alzheimer’s disease.
“If these findings are confirmed in future studies, they might have a large effect on the estimation of the burden of disease and healthcare costs attributed to transportation noise,” noted the study authors.
“Expanding our knowledge on the harmful effects of noise on health is essential for setting priorities and implementing effective policies and public health strategies focused on the prevention and control of diseases, including dementia.”
“Reducing noise through transportation and land use programs or building codes should become a public health priority.”
The study is published in the journal The BMJ.