Researchers: Improving vision may help prevent dementia

Cases of dementia are on the rise with the aging of the world’s population and the emergence of another long-awaited cure for Alzheimer’s disease. crenezumab, has proven ineffective in clinical trials – the latest of many disappointments. Public health experts and researchers say it’s time to turn our attention to a different approach – to focus on eliminating a dozen or so already known risk factors, such as untreated high blood pressure, hearing loss and smoking, rather than prohibitively expensive, releasing new drug.

“It would be great if we had drugs that worked,” the doctor said. Gill Livingston, University College London psychiatrist and chairman Lancet Commission on Dementia Prevention, Intervention and Care. “But that’s not the only way forward.”

Emphasizing changeable risks—things we know how to change—represents a “dramatic change in concept,” the doctor said. Julio Rojas, neuroscientist at the University of California, San Francisco. By focusing on behaviors and interventions that are already widely available and for which there is compelling evidence, “we are changing our understanding of how dementia develops,” he said.

The last modifiable risk factor was identified in US visual impairment study which was recently published in JAMA Neurology. Using data from Health and Retirement StudyThe researchers calculated that about 62 percent of current cases of dementia could be prevented by risk factors, and 1.8 percent—about 100,000 cases—could be prevented by healthy vision.

Although this is a fairly small percentage, it represents a relatively easy solution, the doctor said. Joshua Ehrlich, ophthalmologist and community health researcher at the University of Michigan and lead author of the study.

This is because eye exams, eyeglass prescriptions, and cataract surgery are relatively inexpensive and accessible interventions. “Globally, 80 to 90 percent of visual impairment and blindness can be avoided with early detection and treatment, or have yet to be addressed,” says the doctor. Honestly said.

The influential Lancet Commission led the movement for modifiable risk factors in 2017. A team of physicians, epidemiologists and public health experts reviewed and analyzed hundreds of high-quality studies to identify nine risk factors that account for most of the world’s dementia: high blood pressure, lower education, hearing impairment, smoking, obesity, depression, lack of physical activity, diabetes and low levels of social contact.

In 2020, the commission added three more: excessive drinking, head injuries and air pollution. The Commission estimated that 40 percent of dementia cases worldwide could theoretically be prevented or delayed if these factors were addressed.

“The number of people with dementia can change significantly. 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.”

In fact, in richer countries, “this is already happening as people get more education and smoke less,” she noted. Because the chances of getting dementia increase with age, as more people reach older age, the incidence of dementia continues to rise. But proportions are declining in Europe and North America, where the incidence of dementia has decreased by 13 percent per decade over the past 25 years.

Dr. Ehrlich hopes the Lancet will add visual impairment to its list of changeable risks when it updates its report. Livingston said it would indeed be on the commission’s agenda.

Why can hearing and vision loss contribute to cognitive decline? “The nervous system maintains its function by stimulating the sense organs,” the doctor explained. Rojas, co-author of the accompanying editorial in JAMA Neurology. Without this stimulation, “there will be neuronal death, brain restructuring,” he said.

Hearing and vision loss can also affect cognition, limiting older people’s participation in physical and social activities. “You can’t see the cards, so you stop playing with your friends,” the doctor says. Erlich said, “Or you’ll stop reading.”

Link between dementia and hearing loss, the single most important factor that the Lancet Commission called modifiable risk, is well known. There is less clinical evidence of an association with visual impairment, but Dr. Ehrlich is a co-investigator of a study conducted in southern India to investigate whether wearing glasses in the elderly affects cognitive decline.

Of course, this approach to reducing dementia is “desirable,” he admitted. “We’re not going to eliminate low education, obesity and all that.”

Some efforts, such as improving education and treating high blood pressure, must begin in youth or middle age. Others require major policy changes; For example, it is difficult for a person to control air pollution. Changing habits and lifestyle changes — such as quitting smoking, cutting down on alcohol, and exercising regularly — is not easy.

Even fairly routine medical procedures, such as measuring and monitoring high blood pressure and taking medication to control it, can be difficult for low-income patients.

What’s more, older Americans are likely to notice that routine eye and hearing care are two services that traditional Medicare doesn’t cover.

It will pay for treatment for diabetic retinopathy, glaucoma or age-related macular degeneration, and cataract surgery. But for more common problems that can be corrected with glasses, “traditional Medicare isn’t going to help you much,” said David Lipschutz, associate director of the nonprofit Medicare Advocacy Center. It also won’t cover most hearing aids or exams, which are much more expensive.

Medicare Advantage programs provided by private insurance companies usually include some vision and hearing benefits, “but pay attention to the amount of coverage,” said Mr. K. Lip Protection Warning. “They can spend $200, $300, or $500 on hearing aids,” but at typical prices of $3,000 to $5,000 for a pair, “they can still be far out of reach,” he said.

The expansion of traditional Medicare to include hearing, vision, and dental benefits was part of the Biden administration’s Restoring Better Act. But after the House of Representatives passed it in November, Republicans and Senator Joe Manchin III, a Democrat, flooded it into the Senate.

However, despite warnings and warnings, reducing modifiable risk factors for dementia can have huge payoffs, and the Centers for Disease Control and Prevention has incorporated this approach into its work. National Alzheimer’s Plan.

Focusing on these factors can also help reassure older Americans and their families. Some important risks of developing dementia are beyond our control – genetics and family history, as well as advanced age itself. However, modifiable factors are things we can influence.

“People are so afraid of developing dementia, loss of memory, identity, independence,” says the doctor. Livingston said. “The idea that you can do a lot with it is powerful.”

Even delaying its start can have a big effect. “If instead of getting it at 80, you get it at 90, that’s a huge thing,” she said.

Vision and hearing tests, exercise, weight management, smoking cessation, blood pressure medications, diabetes treatment—”We’re not talking about expensive interventions, fancy surgeries, or visits to specialists that are hours away,” says the doctor. Honestly added. “It’s something that people can do in the communities where they live.”