A study has shown that fish oil supplements may be the key to treating one of the world’s leading causes of blindness.
Researchers have created a new form of omega-3 fatty acid that can penetrate the retina and prevent vision loss associated with Alzheimer’s, diabetes and other diseases.
In a study in rats, the supplement could first be absorbed by the intestines into the bloodstream and then pass through the bloodstream into the retina. This prevents age-related macular degeneration (AMD).
In mice given the new type of supplement, after six months, the amount of an important omega-3 known as DHA increased by nearly 100 percent in their retinas. A laboratory version of the omega-3, known as docosahexaenoic acid (DHA), could be absorbed from the gut into the bloodstream and then from the bloodstream to the retina, unlike the type found in conventional fish oil supplements today.
Scientists have been studying for years whether dietary intake of omega-3 fatty acids can slow vision loss, primarily AMD, which is a common cause of severe vision loss in the elderly.
There are currently no treatments for AMD.
The substance found in fish and krill oil supplements is usually in the form of triacylglycerol (TAG) DHA, which cannot enter the retina from the bloodstream.
“This approach provides a novel therapeutic approach to prevent or mitigate retinal disorders associated with Alzheimer’s disease and diabetes,” said Professor Sugashini Dhavamani, MD, of the University of Illinois at the School of Medicine of Chicago and lead author of the report.
Human studies of this specific omega-3 have not yet begun. But promising early results show that more than 23 million people could benefit from the new dietary supplement. People with Alzheimer’s disease, as well as diabetes, a group of rare eye diseases called retinitis pigmentosa, age-related macular degeneration, and peroxisomal disorders that affect metabolism, often have abnormally low levels of DHA in the retina, resulting in visual impairment.
And while omega-3s come in supplement form, they are also found naturally in many foods, including salmon and other fish, leafy greens, whole grain bread, and nuts.
The researchers tested their LPC-DHA supplement in mice that were bred to show processes similar to those found in early-onset Alzheimer’s disease.
After six months, mice treated with LPC-DHA daily experienced a 96% improvement in retinal DHA content, as well as preservation of retinal structure and function.
Meanwhile, TAG-DHA supplementation had no effect on DHA levels or function in the retina.
In healthy eyes, DHA is concentrated in the retina, where it helps maintain photoreceptors, the cells that convert light into signals that are sent to the brain. Healthy levels of DHA in the retina protect against damage from exposure to bright light and oxidative stress.
Recent studies have also shown that people with higher blood levels of DHA are better protected against Alzheimer’s and other types of dementia.
Their dose of LPC-DHA was equivalent to 250 to 500 milligrams of omega-3 fatty acids per day for a human, which is roughly the range recommended by the U.S. National Institutes of Health and the American Heart Association.
The researchers, who will present their results this week at the annual meeting of the American Society for Biochemistry and Molecular Biology, said more research is needed to confirm that LPC-DHA is safe and effective for human use.
Source: Daily Mail
