Dementia

Poor hearing associated with brain changes

Photo credit: Andrea Piacquadio from Pexels

by Daniel Fink, MD, Chair, The Quiet Coalition

Bryan Pollard, founder of Hyperacusis Research, Ltd., is an electrical engineer. Almost every time I have discussed something with him, he asks me an important question: “What’s the cause? What’s the effect?”

It is very easy to make a mistake thinking that an association is causal when it is not.

One of the best ways to avoid making this mistake is to study a phenomenon over time. If a factor in some research subjects is associated with changes over time, and absence of that factor is not associated with the change being examined, causality is more likely.

A good example of this question is the association of hearing loss with the development of dementia. Maybe hearing loss causes dementia because there is decreased nerve stimulation of certain parts of the brain related to auditory and speech processing, but maybe the brain changes are independent of hearing loss or perhaps even the cause of the hearing loss.

This recent report in JAMA Otolaryngology-Head and Neck Surgery, with an accompanying editorial, uses the study of brain changes over time to try to answer this question. The research was done on the well-studied population of the Baltimore Longitudinal Study of Aging. Hearing tests and studies of brain tissue using specialized research techniques were done. Imaging was done by MRI at the National Institute of Aging.

Results showed that poorer hearing at baseline was associated with specific changes in portions of the brain processing auditory input, but not in other areas of the brain. The editorial notes the limitations of the study and its preliminary nature, but the report is another piece of the puzzle linking hearing loss to dementia.

For at least five years, I have been saying, “If it sounds too loud, it IS too loud.” But based on the accumulating evidence of the dangers of noise for hearing loss, and then the impact of hearing loss on social function, economic success, and the development of dementia, I’ve decided to change my advice.

Now I would say, “If it sounds loud, it IS too loud.”

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.

Noise and air pollution may be preventable causes of dementia

Photo credit: Elina Krima from Pexels

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.

Dementia isn’t inevitable, and neither is hearing loss

Photo credit: Andrea Piacquadio from Pexels

by Daniel Fink, MD, Chair, The Quiet Coalition

This new study from the Alzheimer’s Cohorts Consortium, published on an open access basis in the medical journal Neurology, reports that dementia rates appear to be on the decline in Europe and North America. Analyzing results from seven different research studies, the Consortium found that the incidence of dementia declined 13% per decade in the last 40 years, with a confidence interval of 7-19% per decade. The decline was more pronounced in men than in women.

It is difficult to find the cause for the decline, but the researchers think it is due to a focus on treating cardiovascular risk factors, including reductions in smoking, better blood pressure control, and the use of antithrombotic medication. The article states, “[w]hile none of these has been specifically intended to halt cognitive decline, decades of cardiovascular risk management have likely had substantial effects on brain health, supported by reduction of small-vessel disease on brain imaging in more recent years.“

Why am I writing about a decline in dementia in a blog about noise issues?

Is it because research shows that hearing loss is a possible contributing factor to the development of dementia? No, although that statement is accurate.

The reason is that dementia used to be thought of as an inevitable part of aging, but that’s not true. Many cases of dementia have a vascular cause, and can be prevented by treating cardiovascular risk factors.

Similarly, hearing loss is thought to be part of normal aging, as shown by the use of the terms “age-related hearing loss” and “presbycusis”.

I presented a paper at the 12th Congress of the International Commission on the Biological Effects of Noise in Zurich in 2017, reviewing literature that showed that hearing loss was not an inevitable part of aging but largely represented noise-induced hearing loss. A recent research paper from the Massachusetts Eye and Ear Infirmary confirms that conclusion using ear tissue from post-mortem specimens.

I’ve said this before, but it bears repeating: If a noise sounds too loud, it is too loud.

If you protect your hearing–by avoiding loud noise and using hearing protection when you can’t–you should be able to hear well when you get old. And maybe you’ll reduce your chance of developing dementia, too.

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.

Can hearing aids help prevent dementia?

Photo credit: Vilma Liella licensed under CC BY-SA 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

Can hearing aids help prevent dementia? This comprehensive article in the New York Times magazine section discusses the research suggesting that they might.

Of course, it’s far better to prevent hearing loss in the first place by avoiding loud noise exposure or using earplugs if one can’t avoid the noise. And it’s far cheaper, too.

There are smart phone sound meter apps to measure ambient noise levels, but one doesn’t need a sound meter to know if it’s too loud. If the noise is loud enough to interfere with conversation at the normal social distance of 3 to 4 feet, it’s loud enough to damage your hearing.

Just remember: if it sounds too loud, it is too loud!

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.

Keep your brain healthy by protecting your hearing

Photo credit: Silver Blu3 licensed under CC BY-SA 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

Jane Brody’s recent column in The New York Times discusses the importance of good hearing for brain health. The exact mechanism isn’t understood, but the evidence is clear: even slight hearing loss has significant effects on brain function.

Research is under way to learn if using hearing aids prevents or delays the onset of dementia in those with hearing loss. In the meantime, we recommend avoiding loud noise exposure to prevent hearing loss, because noise-induced hearing loss is 100% preventable.

Remember: if a noise sounds too loud, it is too loud. Leave the noisy environment or protect your hearing now, or wear hearing aids later.

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.

More than Hearing Loss: APHA points to growing health effects of noise

Photo: Dr. Jennifer Deal giving her presentation on hearing loss and dementia

by Jamie L. Banks, PhD, MS, Executive Director, Quiet Communities, Inc., Co-Founder, The Quiet Coalition

Noise is not just a nuisance, it’s a growing public health hazard and action is long overdue.

That’s the message delivered at the November 2019 annual meeting of the American Public Health Association in Philadelphia, where doctors and other specialists identified evidence that “environmental noise” underlies a myriad of health problems reaching well beyond hearing loss.

The sources of this noise range widely, from aircraft takeoffs and landings, construction activity and loud music, to gas-powered lawn and garden equipment and widespread use of personal listening devices. The related health effects that were described include dementia, heart disease, diabetes, sleep disruption, and obesity, all brought about by the body’s reaction to noise-induced stress.

Dr. Leon Vinci, adjunct faculty at Drexel University and session moderator, opened the workshop by stating “there is a clear connection between excessive and unwanted noise with detriments to health and well-being.” The goals of the session were to raise awareness and issue a call to action.

Half the adult US population over age 60 “are impacted by a clinically meaningful hearing loss,” Dr. Jennifer Deal, a Johns Hopkins University epidemiologist, reported, “and there is growing recognition that hearing loss is associated with dementia—with up to 9 percent of global dementia cases attributed to hearing loss.”

Dr. Mathias Basner, associate professor at the University of Pennsylvania’s Department of Psychiatry, pointed also to the extent that unwanted noise contributes to cardiovascular disease. “While the effect of noise on cardiovascular disease risk is relatively small, it still constitutes an important public health problem as so many people are exposed to relevant noise levels,” he said. Sound insulation measures help mitigate some of the negative health effects of noise, but reducing noise at the source still makes the most sense.”

The title given to the APHA meeting session, “Environmental Noise: the New Second-Hand Smoke,” likened the problem to that which has prompted limits nationally on smoking tobacco in public places. Dr. Lucy Weinstein, co-chair of APHA’s Noise and Health Committee, said the reports give impetus to updating and acting on the organization’s 2013 noise policy statement that advocated federal action.

“The ways in which we define and measure noise contribute to [political] inattention to noise as a public health problem,” said Dr. Jamie Banks, executive director of Quiet Communities Inc., a Massachusetts-based nonprofit educational and advocacy organization. Banks cited a revised definition offered by Dr. Daniel Fink, founding chair of The Quiet Coalition, a QCI program. This change would elevate the threshold followed by engineers and physicists from “unwanted noise” to “unwanted and/or harmful sound.”

Furthermore, present methods for measuring sound do not necessarily reflect the real-world impact of noise on health and communities, like low-frequency components in landscape, construction, and air traffic noise, Banks said. As an example, harmful noise from a gas-powered leaf blower carries a longer distance than that from a battery electric blower even though both are rated at the same decibel level. “We have the technology to better understand the noise characteristics that impact health and community– it’s time to employ it.”

Dr. Arline Bronzaft, a City University of New York professor emerita and longtime advocate for controlling urban noise, argued that mounting scientific and medical evidence demands action. She urged APHA members to renew support for the organization’s noise control policy published in 2013.

“The evidence on noise as a public health hazard was convincing 40 years ago,” Bronzaft said. “Now, despite even stronger evidence linking noise to adverse effects on hearing, the cardiovascular system, metabolism, and psychological health, learning, and cognition, we are not moving forward aggressively enough to reduce the many sources of noise pollution in our communities.”

Jamie L. Banks, PhD, MSc, is the Executive Director of Quiet Communities, Inc. and the Program Director of The Quiet Coalition. She is an environmentalist and health care scientist dedicated to promoting clean, healthy, quiet, and sustainable landscape maintenance, construction, and agricultural practices. Dr. Banks has an extensive background in health outcomes and economics, environmental behavior, and policy.

 

Noise disrupts sleep. Could this be linked to Alzheimer’s?

Photo credit: Alyssa L. Miller licensed under CC BY 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

The most common definition of noise is “noise is unwanted sound.” We at The Quiet Coalition recently came up with a new definition: noise is unwanted and/or harmful sound. The specific evidence-based sound levels associated with adverse health and public health hazards are summarized in my article in Acoustics Today, “Ambient Noise Is ‘The New Secondhand Smoke.'”

Sounds as low as 30-35 A-weighted decibels* can disrupt sleep. Uninterrupted sleep is important for both daily function and health. Nighttime noise is increasing, caused by aircraft noise, road traffic noise, emergency vehicle sirens, horn-based alerts, and sounds from clubs, bars, and concerts, with the specific noise source(s) depending on where people live.

It has been known since 2013 that sleep is necessary for cellular cleaning functions in the brain. A new study, reported by NPR, extends this research to Alzheimer’s disease. It has been known for some time that poor sleep is associated with Alzheimer’s disease, and patients with Alzheimer’s disease don’t sleep well. The new study shows that there are waves of cerebrospinal fluid occurring every 20 seconds during sleep, preceded by electrical activity. The electrical waves appear as slow waves on an EEG. Those with Alzheimer’s disease have fewer slow waves on their EEGs.

I have only read the NPR report, not the underlying article in Science, and I’m not 100% sure the cause-effect relationship between sleep disruption and Alzheimer’s has been clearly established. Which really came first, the sleep problems or the Alzheimer’s disease? Nonetheless, the study underscores the importance of a good night’s sleep.

Noise pollution is a public health problem. And one wonders if the increase in Alzheimer’s disease is due in part to increased nighttime noise levels.

*A-weighting adjusts sound measurements to reflect the frequencies heard in human speech.

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.

Can hearing aids delay development of dementia?

by Daniel Fink, MD, Chair, The Quiet Coalition

Can hearing aids delay the development of dementia in older people? This question has been discussed since research showed an association between hearing loss and dementia, with greater hearing loss being associated with a greater chance of dementia. This study indicates that the answer may be “yes.” 

The study is based on insurance claims data, not clinical data, so clinical studies are needed to confirm the results. But in analyzing data on 79 million adults insured by a private health insurance company, hearing aid use among adults diagnosed with hearing loss was associated with a decreased risk of Alzheimer’s disease or dementia.

Hearing loss leads to lack of brain stimulation, social isolation, and depression, all of which have been linked to development of dementia. So the results of the study make sense. It’s possible that treating hearing loss with hearing aids may help delay or prevent dementia.

Of course, preventing hearing loss in the first place is far better and far cheaper than providing hearing aids to those with hearing loss, and certainly cheaper than treating dementia. And preventing most hearing loss is easy: avoid loud noise exposure or wear hearing protection if one can’t.

Because if something sounds too loud, it is too loud.

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.

Association of hearing loss with dementia

Photo credit: Fechi Fajardo licensed under CC BY 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

This article in JAMA Network Open reports an association of hearing loss with the development of dementia in Taiwan. Similar associations have been reported in the United States.

Prevention of hearing loss and provision of hearing aids might help, but I prefer prevention in the first instance.  After all, prevention is almost always better and cheaper than treatment, especially for auditory disorders, and noise-induced hearing loss is 100% preventable.

So to preserve your hearing and more, avoid loud noise or use hearing protection if you can’t. And remember: if something sounds too loud, it IS too loud.

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.

Better hearing and sight can help keep memory sharper

by Daniel Fink, MD, Chair, The Quiet Coalition

This report describes studies showing that giving hard of hearing older patients hearing aids reduced memory loss, as did cataract surgery in another study. It makes sense that more sensory input keeps the brain connections active. There are a number of studies with similar results.

As I get older, I’m intrigued by aging. People of the same chronological age can have dramatically different health profiles, activity levels, and intellectual capabilities. Why? Certainly genetics plays a role, as does diet, physical activity, smoking, alcohol intake, and many factors not yet understood. Yet despite our best efforts, we all eventually die. I think the goal should be compression of morbidity, that is, living full and active lives until one gets sick and dies relatively quickly.

That we have treatment of medical problems is great, but prevention is better. This applies to hearing and vision, too.

Avoiding loud noise prevents noise-induced hearing loss, the most common cause of hearing loss in the U.S. and probably in the developed world. There’s some evidence that what is called age-related hearing loss is really noise-induced hearing loss. And cataracts can largely be prevented by avoiding sun exposure and wearing sunglasses when outside.

But there’s no excitement in prevention, and little if any profit to be made for pharmaceutical companies, doctors, and hospitals. So the obviously better option–preventing damage to sight and hearing in the first place–is given short shrift.

Until prevention prevails, make sure your elderly relatives have their hearing and sight checked–hearing aids and cataract surgery might help prevent 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.