Researchers found that omega-3 polyunsaturated fatty acids protect against the development and progression of retinopathy in mice.
“The retina has one of the highest concentrations of omega-3 fatty acids in the body,” points out lead author, Kip M. Connor, Ph.D., a postdoctoral research fellow at Children’s Hospital Boston. “Given this, it is remarkable that with only a 2% change in dietary omega-3 intake, we observed an approximate 40 to 50% decrease in retinopathy severity.”
The team studied the effect of the omega-3 fatty acids EPA and DHA derived from fish and the omega-6 fatty acid arachidonic acid on the loss of blood vessels, the regrowth of healthy vessels, and the growth of destructive abnormal vessels in a mouse model of oxygen-induced retinopathy. The retinopathy in the mouse shares many characteristics with retinopathy of prematurity in humans. There are also aspects of the disease process that may apply to diabetic retinopathy and age-related macular degeneration.
To test the apparent beneficial effect of omega-3 fatty acids, the scientists compared mice fed a diet modeled after a traditional Japanese diet (more omega-3 than omega-6 fatty acids) and mice on a traditional Western diet (lower amounts of omega-3 fatty acids). In addition, they studied mice genetically altered with a gene that mammals normally lack that converts omega-6 into omega-3 fatty acids. They found that the mice with higher amounts of omega-3 had a nearly 50% decrease in retinopathy.
The investigators observed that omega-3 fatty acids create bioactive mediators that protect against the growth of abnormal blood vessels. In part, this occurs because these mediators suppress tumor necrosis factor alpha (TNF-alpha). TNF-alpha is found in one type of cell, microglia, that can be closely associated with retinal blood vessels.
The study was a collaborative effort by researchers at Children’s Hospital Boston, Brigham and Women’s Hospital, Massachusetts General Hospital, the University of Goteborg in Sweden, the National Eye Institute, and National Institute on Alcohol Abuse and Alcoholism. It appears in the July issue of Nature Medicine.