Link between Macular Degeneration and Cognitive Decline

Link between Macular Degeneration and Cognitive Decline

As your eyes age there is a chance you will need glasses. Either for reading, seeing long distances or both. Wearing corrective lenses helps the brain cope with visual compromise, so it doesn’t need to work so hard to constantly try to correct the issue by itself. However, the longer one waits to get their eyes checked or ignores visual decline, the longer one could be setting themselves up for cognitive (brain) decline. On the other hand, as the brain copes with cognitive diseases such as dementia, Parkinson’s or Alzheimer’s, visual compromise may occur as a result, including macular degeneration or AMD, age-related macular degeneration.

Learn how research is connecting the link between macular degeneration and cognitive decline as well as ways to mitigate this response through simple lifestyle adjustments. It is never too late to strengthen your vision as well as overall health, even if currently compromised by AMD.

Working In Unison

Studies are increasingly showing how the brain and eyes need one another to function. When a breakdown begins in one region the other can suffer.

According to a meta-analysis study of the link between macular degeneration and cognitive decline published in the British Journal of Ophthalmology, it was reported that, 

“Among 2159 citation records, we identified 21 studies consisting of 7,876,499 study subjects for meta-analysis. Patients with dementia or AD [Alzheimer’s disease] were at risk for AMD, particularly for late AMD. AMD was also significantly associated with increased risk of AD/cognitive impairment. Moreover, patients with AMD had poorer cognitive functions when compared with controls,…A significant association between dementia/AD and AMD calls for greater clinical awareness.”

It seems that either disease correlates with the other. This was found through tracking specific proteins that function in both diseases and how they might interact. 

Research titled, ‘New Study Links Protein Causing Alzheimer’s Disease With Common Sight Loss’ by scientists at the University of Southampton, as reported by Science Daily, stated,

“Newly published research has revealed a close link between proteins associated with Alzheimer’s disease and age-related sight loss. The findings could open the way to new treatments for patients with deteriorating vision,…The researchers hope that one of the next steps could be for anti-amyloid beta drugs, previously trialled in Alzheimer’s patients, to be re-purposed and trialed as a possible treatment for age-related macular degeneration.” 

Amyloid Connection

The anti-amyloid beta drugs, mentioned in the above research, attempt to rid the brain of ‘amyloid plaque’ which is believed to form in the brain and possibly lead to Alzheimer’s and other dementias. Now scientists are finding this similar protein in the eye and believe it could be a causation of macular degeneration. 

Published in Neural Regeneration Research, research shows the amyloid connection,

“The results show striking similarities to early-intermediate AMD, reproducing features such as pigment abnormalities, disrupted, hyperplastic RPE, BrM breakage as well as loss of POS [photoreceptor outer segments] within a relatively short period. As such, our acute Aβ-injection [Alzheimer’s-linked amyloid beta] mouse model represents a powerful tool in the arsenal to study AMD. Our discoveries into how Aβ impairs retinal neurons at single-cell resolution provide the first insights into how the retina may become damaged over decade-long Aβ exposure.”

Watch Symptoms

Sometimes it is just a symptom of low visual acuity that may determine the beginnings of cognitive decline. These subtle symptoms are exactly the signs macular degeneration presents and researchers are now beginning to see the link. 

A nationwide study of low vision and the risk of dementia published by Scientific Reports found that,

“In conclusion, individuals with low visual acuity have increased risks of dementia. The medical costs of these dementia are projected to almost double over the next 10 years. Therefore, attention to associated risk factors is important in terms of general health. The results of this study suggest that low visual acuity is an independent risk factor of dementia that must be considered when preparing health policies.”

Signs of low visual acuity related to macular degeneration as reported by the Mayo Clinic include:

  • Visual distortions, such as straight lines seeming bent
  • Reduced central vision in one or both eyes
  • The need for brighter light when reading or doing close-up work
  • Increased difficulty adapting to low light levels, such as when entering a dimly lit restaurant
  • Increased blurriness of printed words
  • Decreased intensity or brightness of colors
  • Difficulty recognizing faces
  • A well-defined blurry spot or blind spot in your field of vision

These symptoms should not be ignored. Addressing them in a timely manner could lead to a good conventional and traditional treatment approach to not only AMD but cognitive decline as well.

Natural Treatments for Macular Degeneration and Cognitive Decline 

Now that these two affliction have been linked to one another, slowing down the progression of both could be applied to medical (conventional) as well as natural (traditional) applications. 

It isn’t that hard to create a healthy eating protocol that can benefit visual as well as cognitive function. As there are few, if any, studies showing the benefits of a predominately animal product (red meat, chicken, fish, eggs, dairy) diet, filling your plate with more plant-based choices could propel half the battle.

The Mediterranean diet is recommended as an optimal choice for both eyes and brain. These studies show the benefits. 

Research from the Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, Maryland, published in the journal Ophthalmology stated, 

“Closer adherence to a Mediterranean-type diet was associated with lower risk of progression to late AMD and to large drusen [waste plaque that may contribute to AMD]. The signal was greater for GA [geographic atrophy] than neovascular [development of new blood vessels] AMD. Fish intake contributed to this protective association. CFH genotype strongly influenced these relationships. These findings may help inform evidence-based dietary recommendations.”

A study published in Current Opinion in Clinical Nutrition and Metabolic Care titled ‘Mediterranean diet and cognitive function in older adults’ showed that,

“Results are provided from only two recent prospective cohorts of older Americans and French individuals (≥65 y) on the relationship of Mediterranean diet to cognitive functions. A high adherence to the Mediterranean diet has been associated with slower cognitive decline, with reduced risk of Mild Cognitive Impairment conversion to Alzheimer’s Disease (AD) and with reduced risk of AD.”

Adding in a good herbal and vitamin protocol that can stoke cognitive function while strengthening against or slowing the progression of macular degeneration could also help. Herbs and vitamins associated with AMD are referred best in the AREDS II formula. This recipe is named after the Age Related Eye Disease Study includes: 

  • Zinc
  • Zeaxanthin
  • Lutein 
  • Copper
  • Vitamin C
  • Vitamin E

Cognitive supplementation includes a wide range of options with many backed by science. Some vitamins and herbs to look for include: gingko biloba, Curcumin (turmeric), B-vitamins, Vitamin D3 and folate. In fact, folate may be more important for cognitive health than most think. 

A recent study posted by Frontiers in Neuroscience found that,

“AD [Alzheimer’s disease] patients had lower levels of folate than healthy controls. Folate deficiency/possible deficiency may increase the risk for AD. Sufficient daily intake of folate may reduce the risk of AD occurrence. Trials have already shown that folic acid supplementation can slow cognitive decline and brain atrophy in patients with mild cognitive impairment,”

Folate is known as vitamin B9 but is usually sold as folate or folic acid. Good food sources of folate include: broccoli, Brussel sprouts, asparagus and fortified cereals.

Keep your eyes and brain firing on all cylinders to prevent them from falling like a house of cards. They are an intertwined system that seems to be a running theme as research discovers more deep connections previously overlooked throughout the brain and body link. 

Sources:

https://pubmed.ncbi.nlm.nih.gov/31000510/

https://www.sciencedaily.com/releases/2021/03/210310122439.htm

https://www.nature.com/articles/s41598-020-66002-z

https://www.mayoclinic.org/diseases-conditions/dry-macular-degeneration/symptoms-causes/syc-20350375

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5436342/

https://pubmed.ncbi.nlm.nih.gov/32348832/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2997798/

https://www.frontiersin.org/articles/10.3389/fnins.2021.661198/full