Omega-3 fatty acids can help prevent retinopathy, which is an eye disease that can lead to blindness in people with diabetes and premature babies. Retinopathy causes abnormal blood vessels to grow in the retina, the light-sensitive tissue lining the inner surface of the eye.
This growth can cause the retina to detach from the back of the eye leading to vision loss.
Dr Lois Smith, a professor of ophthalmology at the Harvard Medical School, says "For people who have had diabetes for 25 years, more than half of them will have retinopathy. It is a extremely common disease that's getting even more common because it increases with obesity."
Previous studies had shown that eye diseases, such as retinopathy, are slowed down in people who eat a lot of fish. In their study, which appears in the journal Science Translational Medicine, Dr Smith and her colleagues looked for the specific metabolic process that produced this protective mechanism.
Mice were fed a diet high in omega-3 fatty acids & found it prevented abnormal blood vessel growth in the retina. They found an enzyme called 5-lipoxygenase, or 5-LOX, converted omega-3 into an acid called 4-HDHA, which slowed abnormal blood vessel growth.
"We found that it was produced by a specific pathway where we eat this essential fatty acid, and then it's made into a sub-product (4-HDHA) that specifically prevents disease formation," Dr Smith said. Researchers also found the benefits of omega-3 are not affected by drugs such as aspirin or other painkillers. "This is important for people with diabetes, who often take aspirin to prevent heart disease," Smith said.
These findings provide new information on how omega-3s work, making them an even more promising option to other drugs currently used to treat retinopathy. "We found that it had as big an effect as the current drugs that are used in these diseases, so this is huge in terms of increasing medical costs that are occurring in all countries," Dr Smith said. "Even more important is with the simple intervention just decreasing the disease burden and the horror of blindness in many patients is very exciting.
Dr Lois Smith is currently working alongside the US National Eye Institute, which is conducting a trial of omega-3 supplements in patients with advanced macular degeneration. Smith says, "For many patients that have milder disease there is the possibility that this could prevent the progression and they would never go onto the severe disease-causing blindness."
13 July 2011