Dr. Heber – Eye Health – Colorful Foods & Eye Health You know, you think of a pistachio as being brown. But right here at UCLA in our laboratories at the Center of Human Nutrition, we’re the ones that found out that there actually are these polyphenols called anthocyanins, that account for the purple color inside of the pistachio. And I never realized this until I opened one up and looked at it, that it’s both green and purple on the inside. The green color represents a substance called lutein, which is localized in the back of your eye in the retina, the part catches light. And it’s concentrated there and helps to prevent the most common form of blindness called age‐related macular degeneration. The purple polyphenols are among the most powerful antioxidants we know of and they’re found in pomegranate and red wine and we know they’re healthy for you. And they’re also found in the pistachio.