by Daniel Fink, MD, Chair, The Quiet Coalition
Noise and air pollution may be preventable causes of dementia. This new study from the Alzheimer’s Association International Conference, reported by Med Page Today, discusses risk factors contributing to dementia. Other than rare genetic conditions, most cases of dementia have multifactorial causation. This makes prevention difficult because multiple risk factors must be addressed.
In general, a healthier lifestyle, including not smoking, eating a Mediterranean style diet, daily exercise, and other similar behaviors, have been shown to reduce or delay the onset of dementia. The new study found that risk factors contributing to dementia include hearing loss, social isolation, depression, and air pollution. These factors have now also been added to the Lancet Commission’s list of key modifiable risk factors for dementia.
Although the study doesn’t mention noise explicitly, noise causes hearing loss. Hearing loss in turn is associated, likely causally, with social isolation. People who can’t understand what others are saying tend to avoid social interaction because it’s too stressful or too embarrassing not to understand what others are saying. Social isolation in turn leads to depression.
With regard to hearing loss, researchers think the loss of auditory input caused by hearing loss also causes changes in the brain that contribute to the development of dementia. Previous studies led by researchers from Johns Hopkins have shown that hearing impairment in people 45-65 years old is related to a progressive loss of nerve cells in brain structures and reduced microstructural integrity that may indicate early Alzheimer disease.
The precise mechanisms by which air pollution contributes to dementia are unclear, but there are strong correlations between levels of pollutants and dementia. Much if not most of urban air pollution comes from particulate matter emitted by internal combustion engines. These are also a major cause of urban noise.
Reducing noise will prevent hearing loss and its consequences. And if noise from vehicles and other engines is reduced, air pollution will also be reduced.
As we have been saying for some years now, a quieter world will be a healthier world for all.
And, one hopes, it will also be a world with less dementia.
Dr. Daniel Fink is a leading noise activist based in the Los Angeles area. He is the founding chair of The Quiet Coalition, an organization of science, health, and legal professionals concerned about the impacts of noise on health, environment, learning, productivity, and quality of life in America. Dr Fink also is the interim chair of Quiet Communities’ Health Advisory Council, and he served on the board of the American Tinnitus Association from 2015-2018.