Can improving and protecting hearing in old age help stave off dementia?

As yet another Alzheimer’s drug — crenezumab — crashes and burns in clinical trials, many clinicians and researchers are saying we should pay more attention to the prevention arsenal we already have that can help to decrease dementia rates so that expensive treatments of limited effectiveness aren’t needed.

In addition, they are adding another risk factor to the list of things which can be treated or modified to help lessen dementia rates: hearing loss.

Emphasizing modifiable risks — things we know how to change — represents “a drastic change in concept,” said Dr. Julio Rojas, a neurologist at the University of California, San Francisco. By focusing on behaviors and interventions that are already widely available and for which there is strong evidence, “we are changing how we understand the way dementia develops,” he said.

The latest modifiable risk factor was identified in a study of vision impairment in the United States that was published recently in JAMA Neurology. Using data from the Health and Retirement Study, the researchers estimated that about 62 percent of current dementia cases could have been prevented across risk factors and that 1.8 percent — about 100,000 cases — could have been prevented through healthy vision.

Though that’s a fairly small percentage, it represents a comparatively easy fix, said Dr. Joshua Ehrlich, an ophthalmologist and population health researcher at the University of Michigan and the study’s lead author.

That’s because eye exams, eyeglass prescriptions and cataract surgery are relatively inexpensive and accessible interventions. “Globally, 80 to 90 percent of vision impairment and blindness is avoidable through early detection and treatment, or has yet to be addressed,” Dr. Ehrlich said.

The influential Lancet Commission began leading the modifiable risk factor movement in 2017. A panel of doctors, epidemiologists and public health experts reviewed and analyzed hundreds of high-quality studies to identify nine risk factors accounting for much of the world’s dementia: high blood pressure, lower education levels, impaired hearing, smoking, obesity, depression, physical inactivity, diabetes and low levels of social contact.

In 2020, the commission added three more: excessive alcohol consumption, traumatic brain injuries and air pollution. The commission calculated that 40 percent of dementia cases worldwide could theoretically be prevented or delayed if those factors were eliminated.

“A massive change could be made in the number of people with dementia,” said Dr. Livingston. “Even small percentages — because so many people have dementia and it’s so expensive — can make a huge difference to individuals and families, and to the economy.”

You can read the rest of the New York Times article here.

Researchers point out that some risk factors — air pollution, for example — can be difficult for individuals to address. They also point out that Medicare does not currently cover eyeglasses or hearing aids, a major oversight in dementia prevention efforts that could save the country billions in dementia hospitalization, treatment and long-term care.

But the main takeaway is still that little changes can add up to a lot of prevention if doctors and allied health professionals put more emphasis on the lifestyle changes both later and early in life that are already lessening some dementia rates in the largest western economies.

The article notes that President Biden tried to address both hearing and eye care treatment using Medicare benefits in his Build Back Better bill, which the Republicans and Sen. Joe Manchin (D-WV) scuttled.

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