A new Tufts University and Tufts Medical Center study found that eating a handful of pistachios every day can keep your eyes healthier for longer.
In the trial, adding pistachios—an easily absorbed source of lutein and zeaxanthin—to the daily diet increased the optical density of macular pigment (MPOD) in healthy adults.
Lutein and zeaxanthin are carotenoids found in fruits and vegetables, especially leafy greens. They cross the blood–brain barrier and accumulate specifically in the macula, where they act as macular pigment.
Pistachios, often thought of as nuts but actually the seeds of a stone fruit, contain significant amounts of lutein and zeaxanthin.
Dr. Temmi Scott, a researcher and clinical neuropsychologist, said their results showed pistachios are not only a nutritious snack but can also be very beneficial for eye health. He emphasized that people face a higher risk of vision decline as they age.
What Did the Study Show?
In the randomized controlled trial, adding 57 grams of pistachios to participants’ usual diets for 12 weeks significantly increased MPOD in healthy middle-aged and older adults.
Consuming pistachios nearly doubled participants’ daily lutein intake and significantly raised lutein levels in plasma, Sci.News reported.
Dr. Scott said adding a handful of pistachios to your diet can boost lutein intake, which is important for protecting your eyes.
He added that pistachios contain healthy fats that may improve lutein absorption.
Lutein also supports brain function. Dr. Elizabeth Johnson, a co-author of the study, said lutein crosses the blood–brain barrier and helps reduce oxidative stress and inflammation. Like in the eyes, lutein accumulates in the brain and may help slow cognitive decline.
The study linked higher lutein levels with better cognitive function—memory and processing speed—suggesting pistachios can be a useful part of a diet for healthy aging. The results were published in the Journal of Nutrition.
