• The research was conducted on mice bred with a specific genetic mutation — Called MTHFR677C>T, this common mutation causes the mice to develop “twisted vessels, narrowed arteries, and reduced branching in the retina,” as early as 6 months of age. These conditions closely resemble the vascular abnormalities seen in human Alzheimer’s patients, and are strongly associated with impaired blood flow and cognitive decline.⁴ Up to 40% of people have this similar mutation.

• Researchers observed striking details in these retinal changes — Unlike the smooth, organized vascular networks typically found in healthy eyes, the altered vessels appeared tangled and distorted. Because the retina and brain share nearly identical tissue, changes in one mirror changes in the other.

“If you’re at an optometrist or ophthalmologist appointment, and they can see odd vascular changes in your retina, that could potentially represent something that is also happening in your brain, which could be very informative for early diagnostics,” Reagan said.

“Your retina is essentially your brain, but it’s much more accessible because your pupil is just a hole, and we can see tons of stuff. All the cells are very similar, all the neurons are quite similar, all the immune cells are quite similar, and they behave similarly under pressure if you’ve got a disease.”

• The problems in the eye went beyond twisted blood vessels — According to the researchers, there was disrupted protein activity in both the brain and retina, too. Proteins are the body’s workers — they manage energy production, clear out waste, and help maintain strong vessel structures.

So when their activity is disrupted, those systems break down, meaning your brain and eyes lose their ability to properly fuel cells, clear out harmful byproducts, and keep vessels strong — setting the stage for Alzheimer’s disease.

• The study also highlighted important differences between male and female mice — Females fared much worse than their male counterparts. By the age of 12 months — roughly middle age for mice — they had fewer blood vessel branches and lower vessel density in their retinas.

This detail is striking because it parallels what doctors already see in humans — women across the globe experience higher rates of dementia compared to men.⁵ Age was another factor that changed the picture, as the retinal disruptions grew more severe as the mice got older.

• The research team is now working to apply these animal findings to humans — They are partnering with Northern Light Acadia Hospital in Maine to test whether similar retinal changes show up in patients carrying the same gene mutation.⁶ If they succeed, it means an optometrist could one day spot Alzheimer’s risk with a simple retinal exam decades before symptoms surface.

• The study involved nine genetically diverse strains of mice — All mice showed some form of retinal aging, but the type and severity of changes differed dramatically between groups.

• The researchers found how varied retinal aging can be — In one strain called Watkins Star Line B (WSB), the mice developed signs of age-related macular degeneration and retinitis pigmentosa, both are serious eye diseases that damage vision over time. In another strain known as New Zealand Obese (NZO), which is prone to metabolic dysfunction, the animals developed diabetic retinopathy, a condition where high blood sugar damages blood vessels in the eye.

• These differences were not random — They were predictable. Molecular changes in the eye accurately forecast which type of degeneration would occur. According to Gareth Howell, a professor at JAX and the study’s lead author:

“There’s more to the eyes than just simply seeing you. By understanding how the healthy eye ages in different genetic contexts, we may be able to determine people’s risk of developing diseases like Alzheimer’s.”⁹

• The study population included more than 8,000 adults who have participated in the EPIC-Norfolk Prospective Population Cohort Study — The participants’ eyesight was tested years before they developed symptoms of Alzheimer’s, via computerized visual sensitivity training, which involves assessing a person’s visual processing speed and reaction time. Ahmet Begde, Ph.D., a doctoral researcher at Loughborough University and one of the study researchers, said:

“Visual sensitivity refers to an individual’s ability to detect and process visual information accurately and efficiently. We decided to investigate visual sensitivity as a predictor of dementia because previous research has shown that individuals with dementia often experience visual processing deficits, even in the early stages of the condition.”¹¹

• The details of the findings showed a strong predictive link — Participants with lower visual sensitivity were far more likely to develop Alzheimer’s within the following decade compared to those with normal visual processing.

“A loss of visual sensitivity can lead to various difficulties in perceiving and processing visual information, such as difficulty recognizing objects or faces, struggles with reading or navigating in familiar environments, and challenges in perceiving visual details or contrasts,” Begde explained. “For example, a person with reduced visual sensitivity may have difficulty reading street signs while driving.”¹²

But this isn’t just about needing glasses or having blurry vision — it was about how the brain interprets what your eyes see. It means struggles with reading, judging distances, driving safely, or distinguishing between colors could be more than just frustrating — they might signal changes in your brain long before memory problems begin.

• Specific improvements came from combining vision tests with traditional neuropsychological exams — Alone, each type of test gives useful information, but when paired, they created a much clearer picture of future dementia risk.

• So what’s the biological explanation for these findings? This is because when Alzheimer’s develops, beta-amyloid plaques — sticky protein clusters linked to cell damage — disrupt both the brain and the pathways that process vision. This disruption reduces the efficiency of visual signaling, which shows up as difficulty detecting fine details or contrasts.

Another mechanism involves how the brain clears waste proteins. Inefficient clearance allows buildup that clogs communication between cells, especially in areas tied to vision.

• These results are unsurprising — In a Medical News Today article, Dr. Alexander Solomon, a surgical neuro-ophthalmologist and strabismus surgeon from California, comments that the findings of this study are actually consistent with what he sees in his patients every day. “It isn’t hard to imagine that as the brain is compromised by a process like dementia, some portions that help process our vision are affected,” he said.¹³

1. Lower your risk from hidden vascular stress — If you have high blood pressure, diabetes, or a family history of stroke or dementia, your blood vessels are under extra pressure. These same vessels feed your retina and your brain, so keeping them strong is key.

Eliminate seed oils and processed foods from your diet, as they damage vessel walls, and replace them with tallow, ghee, or grass fed butter. I also recommend adding regular movement into your lifestyle, such as walking every day, to keep your circulation healthy and blood vessels flexible.

2. Balance your carbohydrates to protect energy production — Your brain and retina run on energy, and that energy depends on carbs. I recommend eating 250 to 300 grams of clean carbohydrates daily, unless you are very active and need more.

Start with fruit, fruit juice with pulp, or root vegetables before you try complex starches. If you have gut problems, sip dextrose water slowly throughout the day. This keeps your mitochondria producing energy smoothly, which is foundational for preventing the decline that shows up in Alzheimer’s.

3. Clear out protein waste before it builds up — To help your body clear out waste proteins, you need efficient sleep and strong circadian rhythms. Expose yourself to sunlight in the morning to reset your internal clock, and avoid blue light screens at night. If you sleep poorly, your brain doesn’t clear out the sticky amyloid that clogs your neurons. I recommend making high-quality sleep a priority because it’s when your brain takes out the trash.

4. Strengthen your retina with regular eye exams — If you are over 50, getting regular annual eye test is essential to help identify early warning signs of Alzheimer’s or dementia. Treat the exam as your early-warning radar, and keep track of results, just like you would monitor blood sugar or cholesterol.

5. Use sunlight and methylene blue to support cellular energy — Your retina and brain cells both rely on strong mitochondrial function to stay alive and sharp. Safe sun exposure helps your cells produce energy directly — however, you need to make sure to eliminate all seed oils from your diet for four to six months before going out during peak sunlight hours. Otherwise, the linoleic acid (LA) in these oils can become embedded in your skin and oxidize under UV rays, causing DNA damage.

Meanwhile, methylene blue, in its pharmaceutical-grade capsule form, has been shown to reduce reductive stress at doses as low as 5 mg once a day. If you spend time in the sun and use methylene blue safely, you give your cells a double advantage — more energy, less stress, and a stronger defense against the breakdowns that fuel Alzheimer’s progression. Read more about it in this article: “Methylene Blue Is Beneficial for Slowing Skeletal Aging and Treating Brain Disorders.”