Eye health: Eating 2 ounces of pistachios daily may help

Evan Walker
Evan Walker TheMediTary.Com |
Fresh pistachios and their broken shells on a flat woody surfaceShare on Pinterest
A new study has uncovered vision-improving benefits from consuming pistachios daily. Orsolya Bán/Stocksy
  • Adding pistachios to one’s diet improves eyesight, according to a new study.
  • The study found that eating two ounces of pistachios daily for 12 days significantly improved the health of macular pigment optical density.
  • Macular degeneration is the leading cause of vision loss for people over the age of 60.
  • The key to pistachios’ vision benefit is the plant pigment lutein, which is unusually bioavailable in nuts.

Eating a handful of pistachio nuts each day can significantly improve eye health, according to a new study from the Friedman School of Nutrition Science and Policy at Tufts University.

Adding two ounces of unsalted, shelled, dry-roasted pistachio nuts each day for 12 weeks to participants’ usual diet improved their macular pigment optical density (MPOD).

The study was supported by the American Pistachio Growers and the National Institutes of Health’s National Center for Advancing Translational Sciences.

The macula is a small area in the center of the retina at the back of the eye. It is critically important for good vision in that it is responsible for central vision, color vision, and capturing fine visual details. These include facial features and written text.

It is not uncommon for macular degeneration to occur as one ages. It is estimated that about 20 million U.S. adults have macular degeneration, which is a leading cause of vision loss and blindness.

Macular degeneration can also occur in younger people. The primary risk factors are:

  • smoking
  • a family history of macular degeneration
  • being overweight
  • hypertension.

Pistachios are unusually rich in bioavailable lutein, a plant pigment that protects the macula from damage from blue light. The study found that participants’ lutein levels increased after only six weeks and doubled by the end of the study.

While treatment for advanced macular degeneration may be possible, it is best to catch the condition early on, when it may be treated nutritionally or with supplements.

The study is published in The Journal of Nutrition.

What distinguishes the pistachio as a high-quality delivery mechanism for lutein is the degree to which it makes the pigment bioavailable, thanks to the nuts’ heart-healthy, mono- and polyunsaturated fats.

“Lutein is also available with heart-Healthy fats in avocados, and in dark leafy vegetables,” said Michelle Routhenstein, MS, RD, CDCES, Preventive Cardiology Dietitian at EntirelyNourished.com, who was also not involved in the study.

She recommended, however, that “to obtain these benefits from broccoli, and spinach, I recommend pairing these greens with nuts, seeds, oils, or fatty fish like salmon.”

Lutein is also capable of crossing the brain-blood barrier.

Routhenstein pointed out that lutein is therefore “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.”

Another plant pigment that can reduce macular degeneration is zeaxanthin. “It’s a fat-soluble antioxidant found in orange peppers, kale, and green peas. To boost its absorption,” Routhenstein suggested, “it’s helpful to consume it with a heart-Healthy fat, or you can opt for a fat source rich in zeaxanthin, like pistachios.”

Two ounces of pistachios is about 50–60 nuts (about 320 calories).

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