Did you know that about 1/5 of the European population is exposed to transportation noise above the recommended level of 55 dB (decibels)? Even if not, it still remains a bad news for our brain health, especially considering the results of a recent observational study. The study investigated the association between long term exposure to road traffic and railway noise and risk of dementia among 1.938.994 adults aged over 60 and living in Denmark over an average of 8.5 years (between 2004 and 2017).
The researchers found that a 10-year average exposure to noise from traffic on roads and railways is linked to a higher risk of developing all-cause dementia. Further analysis by type of dementia showed both road traffic and railway noise were related to a higher risk of Alzheimer’s. Up to 27% higher risk for exposure to road traffic noise of 55 dB and up to 24% higher for exposure to railway noise of 50 dB (compared with less than 40 dB).
As for other types of dementia, only road traffic noise was linked to an increased risk of vascular dementia.
The researchers assume that release of stress hormones and sleep disturbance due to traffic noise are the key factors, leading to a type of coronary artery disease, changes in the immune system and inflammation. All of these consequences are seen as early events in the onset of dementia and Alzheimer’s disease.
Although the study was large, longitudinal and comprehensive, it didn’t consider information about participants’ lifestyle habits, their living factors such as sound insulation in homes, but also other types of noise, such as from airports, industrial activities, or occupational exposure. Something for the upcoming research.
Meanwhile, reducing traffic noise through transportation and land use programs should become a public health priority.
Curious? HERE is the source