NEW YORK, May 6: You might want to start snacking on pistachios. A recent study has identified a simple, nutritious snack that could help protect your vision as you age. Researchers found that eating two ounces of pistachios daily led to significant improvements in the pigments that shield eyes from blue light damage.

Published in January in the Journal of Nutrition, the study explored how pistachios — which contain lutein, a compound with antioxidant properties—impact eye health. The researchers recruited 36 participants aged 40 to 70, all of whom had diets low in lutein. The participants were divided into two groups: one consumed at least two ounces of unsalted pistachios per day (about 50 to 60 nuts), while the other group continued with their usual diets.

Over the course of 12 weeks, the research team monitored the participants' eye health using a method called heterochromatic flicker photometry, which measures macular pigment optical density (MPOD) in the retina. These pigments serve as a natural protective barrier — similar to built-in sunglasses — filtering out harmful blue light that can contribute to age-related macular degeneration (AMD), a leading cause of blindness in older adults.

Blood samples were also taken to assess lutein levels. The results showed that those who ate pistachios experienced a significant increase in both MPOD and blood lutein levels as early as six weeks into the study. These benefits continued through the end of the 12-week period. In contrast, the group that did not change their diets showed no improvement.

“Our findings indicate that pistachios are not only a nutritious snack, but they may also provide significant benefits for eye health,” said Tammy Scott, PhD, research and clinical neuropsychologist and lead author of the study. “This is especially important as people age and face higher risks of vision impairment.”

Interestingly, pistachios are not the highest source of lutein when compared to other foods. However, experts suggest they may be particularly effective due to their natural fat content, which enhances lutein’s bioavailability.

“Lutein is also available with heart-healthy fats in avocados, and in dark leafy vegetables,” said Michelle Routhenstein, a preventive cardiology dietitian at EntirelyNourished.com, who was not involved in the study. To make the most of lutein from vegetables, she added, they should be paired with “nuts, seeds, oils, or fatty fish like salmon” to improve absorption.

Thanks to their fat content, pistachios offer a convenient, ready-to-eat way to boost lutein intake. “By simply incorporating a handful of pistachios into your diet, you can improve your intake of lutein, which is crucial for protecting your eyes,” Scott noted.

The study’s implications may extend beyond eye health. Researchers believe that increasing dietary lutein could also support brain function.

“Lutein crosses the blood-brain barrier, where it may help reduce oxidative stress and inflammation,” explained Elizabeth Johnson, PhD, one of the study’s co-authors.

Routhenstein added that lutein is “a fat-soluble antioxidant that research shows may protect eye, skin, brain, and heart health due to its anti-inflammatory nature and ability to reduce oxidative stress.”

While pistachios are not the richest source of lutein per serving, their combination of nutrients makes them a smart addition to your daily diet. Consuming just two ounces a day may provide the antioxidant support your eyes—and your overall health—need as you age.