A new form of omega-3 oil that crosses into the retina from our bloodstreams could help with visual decline associated with diseases like diabetes, Alzheimer’s disease, and the leading cause of vision loss, age-related macular degeneration (AMD).
Scientists in the Department of Medicine at the University of Illinois have developed a new omega-3 oil that easily enters the eye after being taken orally.
“Omega-3 fatty acids are an unsaturated fatty acid of a kind occurring chiefly in fish oils,” Dr. Daniel Laroche, president of Advanced Eyecare of New York and clinical associate professor of ophthalmology at Mount Sinai’s Icahn School of Medicine, told The Epoch Times.
He emphasized that because omega-3 fatty acids are essential in growth and development throughout life, they should be included in everyone’s diet.
While omega-3s are important for eye health, current formulations, usually in a form called triacylglycerol-DHA (TAG-DHA), do not reach the eye after ingestion, researchers claimed.
DHA, or docosahexaenoic acid, is an omega-3 fatty acid important for maintaining healthy eyes. Our retinas and brains contain the highest concentration of DHA, and we must get it through diet or supplementation because the body can’t make the amount we need to survive.
Low DHA levels are present in the retinas of those with age-related macular degeneration, diabetic retinopathy, and Alzheimer’s disease.
For this study (pdf), scientists created a new lysophospholipid form of DHA, or LPC-DHA, which in animal studies, successfully increased DHA in the retina and reduced eye problems associated with Alzheimer’s-like processes.
“Dietary LPC-DHA is enormously superior to TAG-DHA in enriching retinal DHA and could be potentially beneficial for various retinopathies in patients,” Sugasini Dhavamani, a research assistant professor in the Department of Medicine at the University of Illinois at Chicago, said in a statement.
Dhavamani presented the study at Discover BMB, the annual meeting of the American Society for Biochemistry and Molecular Biology, which occurred from March 25 to 28 in Seattle.
“This approach provides a novel therapeutic approach for the prevention or mitigation of retinal dysfunction associated with Alzheimer’s disease and diabetes,” said Dhavamani.
Researchers tested the hypothesis that LPC-DHA is superior to currently available DHA supplements, including fish oil and krill oil, to enrich DHA in the retina and prevent retinopathy in animal models of early-onset forms of Alzheimer’s disease.
“We showed here for the first time that it is possible to increase the retinal DHA by almost 100 percent in normal adult mice with a low dose of LPC-DHA,” said Dhavamani.
The researchers used dosages that were equivalent to 250 to 500 milligrams per day in humans.
Researchers also showed that retinal DHA cannot be efficiently increased by dietary TAG-DHA or free DHA from available supplements, in their animal model of Alzheimer’s disease.
This discovery might also lead to ways to prevent other retinal conditions, like diabetic retinopathy, as well as AMD, which causes a loss or blurring of central vision.
AMD is a leading cause of severe vision loss in adults, affecting 10 percent of Americans over age 50. It can occur in two forms: atrophic (“dry”) or exudative (“wet”), according to the American Optometric Association. About 20 million people 40 years old and older were living with AMD in 2019, according to U.S. Centers for Disease Control and Prevention (CDC) estimates.
Diabetic retinopathy occurs in Type 1 and Type 2 diabetes and is caused by high blood sugar affecting blood flow to the retina. Untreated, the condition leads to blindness.
Dhavamani and her team emphasized how this discovery could help prevent dementia-related eye problems.
About 2 percent, or 100,000, U.S. dementia cases, were associated with visual impairment. It’s projected that by 2050, that will rise to around 250,000 cases, the National Institute on Aging estimated.
“We believe these studies will have significant effects on the prevention of visual decline in Alzheimer’s disease,” the study authors wrote in their abstract. Abnormalities of the retina in Alzheimer’s include optic nerve degeneration and neuronal loss.
“In Alzheimer’s, you will often have visuospatial issues in these patients,” said Laroche, emphasizing that it’s a “big if” whether these findings apply to humans.
“Will this actually help or prevent disease in humans?” Laroche asked. “Many years of studies remain.”
There are a few reasons why DHA is crucial for eye health.
According to an article in the Journal of Nutrition and Metabolism, DHA is a structural component of the retina. It is also a major structural component of the outer segments of the photoreceptor cells in the retina, which are responsible for detecting light and transmitting visual signals to the brain.
DHA also helps maintain the fluidity and integrity of the membranes in the retina. This is important for the proper functioning of the photoreceptor cells and the efficient transmission of visual information.
DHA is anti-inflammatory, as well; inflammation in the eye can damage delicate structures in the retina and contribute to the development of AMD. These anti-inflammatory properties may also protect the retina in other ways.
Too little DHA in our eyes is associated with several vision-threatening conditions.
Retinal DHA is significantly reduced in conditions like diabetes, retinitis pigmentosa, and AMD, which can lead to functional defects, impaired visual development, and reduced sensitivity.
Asked which eye conditions the currently available omega-3 supplements can help, Laroche noted that these oils most commonly improve the eye’s meibomian glands, which are located on the eyelid margin and produce the oily part of tears.
Improved function of those glands can ease dry eye symptoms.
“Omega-3s have also been shown to be helpful in patients with myopia and macular degeneration,” he noted.
However, there’s little evidence that omega-3 helps when applied to the eye directly.
“Topical omega-3 is a promising treatment for dry eye, but there is a lack of evidence in the scientific literature about topical application,” said Laroche. “Further studies in humans are required to assess the efficacy.”