Serum glucose levels typically rise with age. Here again the finding that various kinds of polyphenols lower blood sugar is of great relevance. Interestingly, Chinese medicine recommends raspberries for vision improvement. And since we have mentioned Oriental medicine, ginkgo too has been shown to have benefits for the retina, thanks to its antioxidant properties, its ability to raise glutathione levels, and its enhancement of the blood-retinal barrier. To put it simply, various potent flavonoids have similar effects, whether on the brain, eyesight or the vascular system.
Egg yolks are a rich source of lutein, as is spinach.
In addition, antioxidant hormones such as estrogens and DHEA may also be protective. References Asgary S et al. Antioxidant effect of flavonoids on hemoglobin glycosylation. The Vita-Nutrient Solution. Protective effects of grape seed proanthocyanidins and selected antioxidants against TPA-induced hepatic and brain lipid peroxidation and DNA fragmentation, and peritoneal macrophage activation in mice.