A Sign Deep Inside Your Eyes Could Warn of Early Dementia
Multiple studies have found links between eye problems and dementia risk. Plaques of amyloid beta proteins, a hallmark of Alzheimer's disease, have even been found in the retinas of people who have it.
Three years ago, researchers from the University of Otago in New Zealand discovered that thinning in a person's retina in middle age can be linked to cognitive performance in their early and adult life. That's the light-sensitive tissue that lines the back of the eye.
The scientists suspected these findings could one day pave the way towards a simple eye test to help predict a person's risk for conditions such as Alzheimer's disease. Now, some members of that team have followed the hunch a step further.
"In our study, we looked at the retina, which is directly connected to the brain," University of Otago psychologist Ashleigh Barrett-Young says.
"It's thought that many of the disease processes in Alzheimer's are reflected in the retina, making it a good target as a biomarker to identify people at risk of developing dementia."
Barrett-Young and colleagues returned to the longitudinal database used in their 2022 research, the Dunedin Multidisciplinary Health and Development Study, which tracked 45 years of health data from New Zealanders born in 1972 and 1973.
For their new research, the team only used data collected from 938 participants at age 45, including retinal photographs, eye scans, and a battery of tests that gauge midlife risk of Alzheimer's and related dementias.
Repeating the major part of their 2022 study, they checked for associations between cognitive decline and retinal layer thickness.
They took special care over the layer of nerve fibers closest to the jelly-filled vitreous cavity that 'fills out' our rounded eyes, and its neighboring layers of ganglion cells and inner plexiform. The nerve fiber layer is particularly important because it carries visual signals to the brain.
They also looked for possible associations with retinal microvascular health, ascertained by measuring the diameter of tiny arteries and veins in the retina. These "are believed to reflect the integrity of the overall cardiovascular system of the body (including the cerebrovasculature), which is implicated in the pathology of Alzheimer's disease and related dementias and, in particular, vascular dementias," the team writes.
It turns out that, at least for the 45-year-old Kiwis involved in the study, retinal microvascular health was a much stronger predictor of dementia risk than the nerve fiber layer.
While thickness of the nerve fiber layer (though not the ganglion cell–inner plexiform layer) was weakly associated with dementia risk, it was nowhere near as strong as the microvascular link.
The team found dementia risk scores were usually higher among people with narrower arterioles (tiny vessels that carry blood away from the heart) and wider venules (miniature veins that receive blood from capillaries).
Medical professionals won't be putting the findings of this study into action just yet, because it's too population-specific and observational. Also, as the authors note, while the dementia risk measures are "highly predictive of the likelihood of dementia decades later", they are by no means a direct measure of actual disease.
Nonetheless, it seems we're getting closer to a world where a routine eye check could help flag the risk of dementia before it hits, and give you more time to plan treatment.
"Treatments for Alzheimer's and some other forms of dementia may be most effective if they're started early in the disease course," Barrett-Young says.
"Hopefully, one day we'll be able to use AI methods on eye scans to give you an indication of your brain health, but we're not there yet."
The research was published in Journal of Alzheimer's Disease.
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Vox
23 minutes ago
- Vox
What if your earbuds could read your mind?
is a senior technology correspondent at Vox and author of the User Friendly newsletter. He's spent 15 years covering the intersection of technology, culture, and politics at places like The Atlantic, Gizmodo, and Vice. The MW75 Neuro headphones are primarily used to sharpen your attention — with the new and added benefit of giving you a snapshot of your brain health. Paige Vickers/Vox; Getty Images; Neurable For the past few months, when I really needed to get something done, I put on a special pair of headphones that could read my mind. Well, kind of. The headphones are equipped with a brain-computer interface that picks up electrical signals from my brain and uses algorithms to interpret that data. When my focus starts to slip, the headphones know it, and an app tells me to take a break. It sounds like something out of science fiction, but a decade-old startup called Neurable is pioneering the technology, and it's preparing to put the brain-tracking tricks into more gadgets. Earbuds, glasses, helmets — anything that can get an electrode near your head could provide a real-time stream of data about what's going on inside of it. Neurable's technology uses a combination of electroencephalography (EEG) sensors to collect brain data and algorithms to interpret those signals. Beyond measuring attention, the company is now using that data to track and improve brain health. User Friendly A weekly dispatch to make sure tech is working for you, instead of overwhelming you. From senior technology correspondent Adam Clark Estes. Email (required) Sign Up By submitting your email, you agree to our Terms and Privacy Notice . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. I want to emphasize again that this technology does not actually read your mind in the sense of knowing your thoughts. But, it knows when you're entertained or distracted and could one day detect symptoms of depression or, on a much more consequential front, early signs of Alzheimer's disease. I came across Neurable on a longer mission to understand the future of health-tracking technology by testing what's out there now. It's one that left me anxious, covered in smart rings and continuous glucose monitors, and more confused about the definition of well-being. That's because almost all health trackers that are popular on the market right now — Apple Watches, Oura Rings, Whoop Bands — are downstream sensors. They measure consequences, like elevated heart rate or body temperature, rather than the root cause of that state. By tapping directly into your brainwaves, a brain-computer interface can spot issues sometimes years before they would show up. It could one day detect symptoms of depression or, on a much more consequential front, early signs of Alzheimer's disease. 'Biologically, your brain is designed to hide your weaknesses: It's an evolutionary effect,' Neurable's co-founder and CEO Ramses Alcaide, a neuroscientist, told me. 'But when you're measuring from the source, you pick up those things as they're occurring, instead of once there's finally downstream consequences, and that's the real advantage of measuring the brain.' Other major tech companies are also exploring ways to incorporate non-invasive brain-computer interfaces into headphones. A couple years ago, Apple quietly patented an AirPod design that uses electrodes to monitor brain activity, and NextSense, which grew out of Google's moonshot division, wants to build earbud-based brain monitors for the mass market. There's also been a recent boom in activity around invasive brain-computer interfaces being developed by companies like Elon Musk's Neuralink and even Meta that surgically implant chips into people's brains. It's safe to say that's not currently a mass-market approach. 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The possibilities are as endless as the list of issues that can affect the brain. The Pentagon has been using Neurable's portable technology to study traumatic head injuries in soldiers, for instance, and that research could have practical applications in sports. Alcaide also mentioned Alzheimer's and Parkinson's as potential targets for their technology. Symptoms for these diseases don't appear for years after onset, but early markers could show up in the kind of EEG data their technology captures from everyday wear. If you changed the technology's mission from measuring focus to, say, symptoms of depression, you could imagine how an everyday gadget could offer some life-changing interventions. For now, however, the MW75 Neuro headphones are primarily used to sharpen your attention — with the new and added benefit of giving you a snapshot of your brain health. 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Neurable encrypts and anonymizes the data coming out of your head and onto its sensors and then again when it goes to your phone, so it's far removed from any personal data. Furthermore, he said, Neurable has no ambitions to be a data company. 'Our business model doesn't depend on identity. We don't sell ads. So there's no benefit,' Molnar said. 'It's actually more of a liability for us to be able to have data map back to an individual.' It's hard for me to say how much more productive I became thanks to the brain-reading headphones. As with many other health trackers, there's sort of a placebo cat effect: Simply deciding to track the behavior changed my state of mind and made me behave a certain way. So, setting up a focus session inevitably made me pay closer attention to how well I was focusing, how often I took breaks, and if I was choosing to be more mindful. This is actually what makes me so curious about an earbud version of what Neurable's doing. I wear AirPods for most of the day, whether it's taking calls for work, listening to podcasts, or just drowning out the sounds outside my Brooklyn apartment. If these earbuds were also collecting data about my cognitive well-being during all those activities, I'd be interested in knowing what I could glean from that information, if only to better understand what's rotting my brain. And I'm sure plenty of companies would be happy to collect more data about their users' states of mind at any given time. Imagine if the TikTok algorithm knew you weren't interested in something — not because you swiped through it but rather because your brainwaves said so. Neurable's website has mockups of EEG-equipped earbuds, helmets, and smart glasses, and it's clear that the company is eager to move beyond its first product. The company doesn't just want to make gadgets, either. It wants to be the leading platform for brain-powered technology. 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Ozempic May Help Prevent This Medical Emergency, According To New Research
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Boston Globe
19 hours ago
- Boston Globe
New hope for Alzheimer's: Groundbreaking Harvard study finds lithium reverses brain aging
The research suggests a new approach to preventing and treating the mind-robbing disease. Advertisement 'It seems to somehow turn back the clock,' said the team's senior author, Dr. The findings come amid a rising tide of Alzheimer's and growing urgency to pinpoint an effective treatment for the For years, researchers believed the buildup of sticky clumps of protein, known as amyloid plaques, fueled the devastating cascade of brain degeneration in Alzheimer's. But Advertisement Yankner now believes that may be a lithium deficiency. Dr. Bruce Yankner sat in his office at Harvard Medical School next to a photograph of a brain with Alzheimers on Monday, Aug. 4. Heather Diehl/For The Boston Globe Lithium has long been used to treat mental health conditions, particularly bi-polar disorder. But the form of lithium typically used for such treatments, lithium carbonate, is different than the one used by the Yankner team, which employed lithium orotate . His team studied brain tissue donated from about 400 people post mortem, as well as blood samples and a battery of memory tests performed yearly before their death. The participants ranged from cognitively healthy at the time of their death to having full-blown Alzheimer's. The scientists found higher levels of lithium in cognitively healthy people. But as amyloid began forming in the early stages of dementia, in both humans and in mice, the amyloid bound to the lithium, restraining it and reducing its availability to surrounding brain cells. That depleted the lithium even in parts of the brain that were amyloid free, essentially reducing lithium's protective function. To test whether lithium depletion was driving the disease or simply a byproduct of it, they fed healthy mice a lithium-restricted diet, draining their lithium levels. This appeared to accelerate their brain aging process, creating inflammation and reducing the ability of nerve cells to communicate. That spurred memory loss in the mice, as measured by their diminished performance in several laboratory memory tests. The researchers then fed a restricted-lithium diet to mice that were genetically engineered to develop Alzheimer's-like amyloid plaques and abnormal tangles of another protein, called tau, and witnessed a dramatic acceleration of the disease. Advertisement These images show what happens to the brains of Alzheimer's mice when they are placed on a lithium deficient diet. It shows that lithium deficiency markedly increases the number of amyloid plaques and the number of tangle-like structures in the brain, resembling advanced Alzheimer's disease in humans. Yankner Lab But they were able to reverse the disease-related damage and restore memory function, even in older mice with advanced disease, by returning lithium to their diet. (Lithium orotate, the compound the scientists used, can evade capture by Alzheimer's amyloid plaques). 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Notably, Advertisement 'When we're thinking about the therapeutics of a replacement, if you're lowering something, you just have to replace it back to the natural levels,' he said. 'That seems a lot safer than introducing something that our body is not used to, or doesn't already need in order to function. ' 'That's a really good rationale for pursuing it,' he said. A number of factors are linked through research to a higher risk of Alzheimer's and dementia including advanced age, family history, and genetics, as well as several modifiable factors such as diet, smoking, hypertension and diabetes. Liviu Aron, first author of the study that links lithium deficiency to Alzheimer's disease, looked at samples of human and mouse brains in the Harvard lab on Aug. 4. Heather Diehl/For The Boston Globe Many foods already touted for their health benefits naturally contain higher amounts of lithium — But Kaeberlein and other researchers said the real test of the Harvard team's findings would be a large clinical trial in people, with half of the participants receiving small doses of lithium orotate and the others a sham substance, to compare the findings. Kaeberlein said the safety track record of this form of lithium, which showed no toxicity in animals, may help speed trials in people. Advertisement The Harvard findings 'line up with a lot of earlier work, both in the brain and in normal aging,' Kaeberlein said. And he added something rarely heard from scientists when discussing cutting-edge research and a potential medication that may fundamentally change the course of a dreaded disease. This work, he said, 'feeds my optimism that this will lead to potential therapeutics.' But one obstacle to advancing the research is the freeze on Kay Lazar can be reached at
