Just 2 handfuls of pistachios daily could help protect your eyesight

For those wondering what two ounces of pistachios looks like, it’s roughly two handfuls, or 50-100 kernels. While this might seem like a lot, it’s worth noting that pistachios also provide other nutritional benefits, including healthy fats, protein, and fiber.

This research opens up new possibilities for protecting eye health through diet, particularly for those who might not regularly consume leafy greens or other traditional sources of lutein. It suggests that something as simple as snacking on pistachios could contribute to long-term eye health.

Paper Summary

Methodology

The researchers recruited 36 participants through social media and carefully screened them to ensure they had low levels of macular pigment and typically ate diets low in lutein. They randomly assigned participants to either eat their regular diet or add two ounces of pistachios daily for 12 weeks. The researchers measured participants’ eye health using a special technique called heterochromatic flicker photometry, which non-invasively measures the density of protective pigments in the retina. They also took blood samples to measure lutein levels and tracked participants’ dietary intake throughout the study.

Key Results

The pistachio group showed significant increases in their macular pigment density at all measured points in the retina after six weeks, and these improvements remained stable through week 12. Their blood levels of lutein also increased significantly. The control group showed no meaningful changes in either measurement. The improvements seen with pistachios were comparable to or better than those seen in previous studies using higher doses of lutein from other sources.

Study Limitations

The study was relatively small (36 participants) and focused on healthy adults between 40 and 70 who had low baseline levels of lutein intake and macular pigment. The results might not apply to other populations. The study also used a relatively high daily dose of pistachios (2 ounces) compared to typical consumption recommendations (1.5 ounces).

Discussion & Takeaways

The study suggests that pistachios could be an effective dietary strategy for increasing protective pigments in the retina, potentially helping to prevent age-related vision problems. The researchers speculate that pistachios’ effectiveness might be due to their fat content, which could help with lutein absorption, and their potential effects on blood lipid profiles, which might influence how lutein is transported in the body.

Funding & Disclosures

The study was funded by the American Pistachio Growers and the National Center for Advancing Translational Sciences, National Institutes of Health. While the American Pistachio Growers provided funding, they had no role in the study’s design, conduct, or interpretation. The lead author reported receiving financial support from American Pistachio Growers, while other authors declared no competing interests.