London: Eating oily fish twice in a week — equivalent to 500 mg per day of dietary omega-3 polyunsaturated fatty acids — can decrease the risk of sight-threatening diabetic retinopathy in middle-aged and older individuals with Type 2 diabetes, finds a study. Diabetic retinopathy is a diabetes complication that affects eyes and has become a leading global cause of vision loss. It is caused by damage to the blood vessels of the light-sensitive tissue at the back of the eye (retina). The increasing prevalence of Type 2 diabetes mellitus, coupled with an increased lifespan, has resulted in a steady rise of disability in older individuals with diabetes. The retina is rich in long-chain omega-3 polyunsaturated fatty acids. Many experimental models have supported dietary long-chain omega-3 polyunsaturated fatty acids’ protection against diabetic retinopathy, however, clinical data is lacking, the researchers said, in the paper published online by JAMA Ophthalmology. The team conducted a prospective study within the randomised clinical trial Prevencion con Dieta Mediterranea (PREDIMED). From 2003 to 2009, 3,614 individuals aged 55 to 80 years with a previous diagnosis of Type 2 diabetes were recruited in Spain.