Eating fatty fish such as salmon, trout or sardines twice a week was associated with a lower risk of diabetic retinopathy, according to a study of people with diabetes which was published in 2017 in JAMA. This is probably because fatty fish have a lot of omega-3 fatty acids, which encourage the development of blood vessel growth, including in the eyes. Omega-3’s have also been linked to a reduced risk of heart disease.