American researchers have developed a form of omega-3 fatty acid, which would be able to penetrate the retina of the eye.
- Docosahexaenoic acid (DHA) is normally concentrated in the retina. A deficiency is associated with loss of vision.
- Scientists have developed a new lysophospholipid acid form of DHA to prevent vision loss associated with Alzheimer’s disease.
- In mice fed with LPC-DHA dietary supplements, a 96% improvement in DHA content in the retina was observed.
In a person with healthy eyes, docosahexaenoic acid (DHA) is concentrated in the retina, where it helps maintain photoreceptors, the cells that convert light into signals sent to the brain. If a DHA deficiency presents in the retina, vision loss may occur.
DHA cannot pass from the bloodstream to the retina
“People with Alzheimer’s disease, as well as those with diabetes, retinitis pigmentosa, age-related macular degeneration (AMD) and peroxisomal disorders, often have abnormally low levels of DHA in the retina, which frequently leads to visual impairments”, indicated scientists from the University of Illinois at Chicago (USA) in a statement.
While increasing docosahexaenoic acid, which comes in a form called “triacylglycerol (TAG),” can help prevent vision loss, it has proven difficult with currently available dietary supplements. According to the researchers, in order for a dietary supplement to deliver DHA to the retina, the DHA must first be absorbed from the gut into the bloodstream and then passed from the bloodstream to the retina.
“It has not been possible so far to increase the amount of DHA in the retina at clinically feasible doses due to the specificity of the blood-retinal barrier which is incompatible with the specificity of the intestinal barrier”, said University of Illinois professor Sugasini Dhavamani at the annual meeting of the American Society for Biochemistry and Molecular Biology, held March 25-28 in Seattle.
Omega-3: 96% improvement in DHA content in the retina
Faced with this observation, the team decided to create a new form of lysophospholipid acid of DHA, or “LPC-DHA”, to prevent vision loss linked to Alzheimer’s disease, diabetes or even Macular degeneration. As part of a study, the authors tested their new dietary supplement on mice. The latter were bred to exhibit processes similar to those found in early-stage Alzheimer’s disease.
After six months, rodents fed daily LPC-DHA (at a dose that equates to approximately 250-500 milligrams of omega-3 fatty acids per day in humans) showed a 96% improvement in DHA content in the retina, as well as preserved retinal structure and function. According to scientists, LPC-DHA dietary supplements may help prevent the decline in visual function associated with Alzheimer’s disease. This approach “overcomes both the intestinal and blood-retinal barriers and improves retinal function”, added the team.