According to the World Health Organization, some form of dementia is experienced by over 55 million people across the world. The number is estimated by experts to cross 150 million by the year 2050 as the population ages.
In order to prevent and manage the health crisis that is glowing, it is essential to identify the risk factors which can be potentially modified.
Traffic Noise May Increase The Risk Of Developing Dementia
A new study of Danish origin suggests that a higher risk of developing dementia, especially Alzheimer’s is increased by exposure to traffic noise.
Noise pollution has been consistently linked to multiple health conditions by various studies in the past. These conditions include obesity, diabetes, and coronary heart disease. The research into the effects of noise on dementia is still scarce.
The researchers, recognizing the need for more testing that is controlled, investigated a potential link between the risk of incident dementia and long-term residential exposure to transportation noise. After air pollution, the second-worst environmental risk factor for public health in Europe is transportation noise.
The recommended level of exposure is below 55 decibels and about 20% of people in Europe are exposed to transportation noise above this level. As sleep is a critical part of the mental and cognitive restoration, this exposure to noise above this level is very concerning especially at night.
An increase in oxidative stress is related to fragmenting sleep that is a consequence of noise disturbance as suggested by experimental studies. It is also associated with alterations in the immune system and increased systemic inflammation. In the onset of Alzheimer’s and dementia, these conditions are regarded by experts as early events signifying the same.
2 million adults aged 60 or older were included in the study. They were people who resided in Denmark between the years 2004 and 2017.
The exposure to road traffic and railway noise was estimated by the researchers for all participants’ residential addresses and focused on the buildings’ most and least exposed sides.
During an 8-year span, all-cause dementia and other kinds of dementia were identified by the team by using Denmark’s high-quality national health registers. Alzheimer’s disease, vascular dementia, and Parkinson’s disease were the conditions that were included.
During this time, more than 103,000 new cases of dementia occurred. A higher risk of all forms of dementia was correlated with noise from road traffic and railways according to further analysis of the data.
The formation of key genes that lead to neuropathological changes is activated by continual exposure of animals to noise. This was found in a study with the hippocampi of mice.
A note of leveling off or decline in hazard ratios at the most exposed sides of buildings are noted by the authors of the study.
The results of investments in better sound insulation are probably being exhibited here.
The results from the study that suggest a higher risk of dementia for those who live in suburban areas is also possibly further explained by the prioritization of noise-reducing measures. This study was observational, even though it was large and comprehensive. It is not possible to establish causality due to this reason.
The lack of information about lifestyle habits poses another limitation to the study. These habits can play a key role in the risk of developing dementia in an individual.
The authors of the study also did not account for the noise from industrial activities and airports. Even occupational noise exposure was not accounted for.
In order to expand global knowledge on the harmful health effects of noise pollution, the researchers have said that future studies are required and are very important.