Avocado Consumption Increases Macular Pigment Density in Older Adults: A Randomized, Controlled Trial Abstract: Lutein is selectively incorporated into the macula and brain. Lutein levels in the macula (macular pigment; MP) and the brain are related to better cognition. MP density (MPD) is a biomarker of brain lutein. Avocados are a bioavailable source of lutein....