Lutein and zeaxanthin are carotenoids primarily found in vegetables and fruits. They can cross the blood-brain barrier and accumulate in the macular region of the retina, where they are referred to as macular pigment (MP). They serve as anti-oxidants, and blue-light filters, protecting the macula from damage induced by light.
Pistachios are a highly bioavailable source of lutein, a key component of MP, which can be measured non-invasively as macular pigment optical density (MPOD). MPOD is influenced by dietary intake of lutein and zeaxanthin (L/Z). Higher MPOD is associated with better eye health and protection against light-induced damage.
A study carried out by Scott et al., which was recently published in the “Journal of Nutrition” evaluated the impact of consuming 2 ounces (57 grams) of shelled pistachios alongside a usual diet (PIS) compared to the usual diet alone (UD) on MPOD. After a 12-week intervention of consuming 2 oz of pistachios daily, the participants in the PIS group showed a significant increase in MPOD at all measured eccentricities compared to the UD group, with improvements sustained at week 12. Serum lutein levels mirrored these results, while serum zeaxanthin levels remained unchanged in both the groups. These findings indicate that pistachio consumption effectively increases MPOD in adults with low L/Z intake (See Graphic).
(Source: Scott TM, Ogunbodede O, McKay D, Johnson EJ. Pistachio consumption increases macular pigment optical density in healthy adults: A randomized controlled trial. J Nutr. 2024. DOI: https://doi.org/10.1016/j.tjnut.2024.10.022)