Adding 57 g of pistachios daily for 12 weeks to a diet increased macular pigment optical density (MPOD) due to the plant pigment lutein found in the nuts. MPOD is an important indicator of eye health. It protects the retina from blue or visible light and is linked to a reduced risk of age-related macular degeneration (AMD), a leading cause of blindness in older adults. In the single-blinded, randomized controlled trial, researchers from the Friedman School of Nutrition Science and Policy at Tufts University, US, selected 36 middle-aged to older healthy participants with low MPOD and low intake of lutein and zeaxanthin, plant pigments that impact MPOD. One group consumed a “usual diet,” while the other added 57 g of pistachios to their daily diet.