Dietary interventions with pistachios — a bioavailable source of the xanthophyll lutein — are efficacious in increasing macular pigment optical density (MPOD) in healthy adults, according to a new study from Tufts University and Tufts Medical Center.
Lutein and zeaxanthin are dietary xanthophylls, a class of carotenoids most commonly found in vegetables and fruits, with green leafy vegetables being especially rich sources.
These compounds cross the blood brain barrier and exclusively accumulate in the macular region of the human retina where they are referred to as macular pigment.
Pistachios are the only nut that contain significant amounts of either lutein and zeaxanthin, but unlike eggs contain only lutein.
Similar to eggs, however, pistachios provide a source of fat, mainly as mono- and polyunsaturated fats, potentially making them a highly bioavailable source of lutein.
“Our findings indicate that pistachios are not only a nutritious snack, but they may also provide significant benefits for eye health,” said Dr. Tammy Scott, a research and clinical neuropsychologist at Tufts University.
“This is especially important as people age and face higher risks of vision impairment.”
The randomized controlled trial showed that compared to eating a usual diet alone, eating 2 ounces (57 grams) of pistachios per day for 12 weeks as part of a usual diet resulted in a significant increase in MPOD in otherwise healthy middle-aged to older adults.
They also found that pistachio consumption nearly doubled participants’ daily intake of lutein and significantly raised its plasma levels.
“By simply incorporating a handful of pistachios into your diet, you can improve your intake of lutein, which is crucial for protecting your eyes,” Dr. Scott said.
“Pistachios provide a source of healthy fat, potentially making the lutein from pistachios better taken up into the body.”
“About 1.6 mg of lutein was provided from pistachios, which would be enough to…
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