New Study Shows Eating Pistachios Daily Can Support Eye Health

2 daily handfuls of pistachios may help protect the eyes from blue light damage and could reduce the risk of age-related vision problems.

FRESNO, Calif., Oct. 24, 2024 /PRNewswire/ -- Could 2 handfuls of pistachios a day help protect your eyes as you age? A new study from researchers at the Friedman School of Nutrition Science and Policy at Tufts University suggests the answer could be yes.¹ The research found that eating just 2 ounces of pistachios every day may significantly improve eye health by increasing levels of a key antioxidant that helps protect vision.

The study, led by researchers Tammy Scott and Elizabeth Johnson of the Friedman School, found participants who followed a dietary intervention including pistachios, which have measurable amounts of a plant-based pigment called lutein,² had an increase in macular pigment optical density (MPOD) compared to participants who did not consume pistachios. MPOD filters harmful blue (visible) light and protects against age-related macular degeneration (AMD), which is one of the leading causes of blindness in older adults.

Findings from this research are timely, as according to a national poll by the American Foundation for the Blind, Americans fear vision loss more than they fear other serious health problems.³

What the Study Found

• Better Eye Health in Just 6 Weeks: Middle-aged and older adults who were otherwise healthy and ate 2 ounces (about 2 handfuls) of pistachios every day saw significant increases in MPOD after only six weeks.
  
  
• Provides Antioxidant Lutein: Pistachios are the only nut with measurable amounts of lutein, an antioxidant and blue light filter that may help protect eyes from light damage and supports long-term vision health. In the study, lutein intakes nearly doubled and blood lutein levels were significantly elevated.
  
  
• Age-Related Vision Protection: The study suggests that pistachios could be a simple, natural way to help reduce the risk of AMD, a serious eye condition that affects millions of people as they get older.⁴

How Pistachios Help the Eyes
“Lutein is an antioxidant that acts like sunglasses for your eyes,” explains Dr. Scott, a research and clinical neuropsychologist and lead author of the study. She adds that lutein is selectively taken up into the retina and helps filter out harmful blue light from computer screens and sunlight and may help reduce damage to the delicate parts of the eye.

Average lutein intakes are very low in the United States,⁵ but adding lutein-rich foods to the diet may help change that. In the study, about 1.6 mg of lutein was provided from pistachios, which would be enough to double the average daily consumption of lutein in adults.⁵

“Higher intake of foods with lutein has been associated with beneficial effects for the eyes. Our study enhances our understanding of the link between nutrition and eye health,” notes Dr. Scott. She adds that pistachios provide a source of healthy fat, potentially making the lutein from pistachios better taken up into the body the body.

More Than Just Eye Health
Pistachios aren't just good for the eyes—they also have other antioxidants and plant-based compounds that could support overall healthful aging including brain health.^6,7,8 "As in the retina, lutein selectively accumulates into the brain, where it may help reduce oxidative stress and inflammation," notes Dr. Elizabeth Johnson, a co-investigator on the study. This makes them a great snack choice for people looking to improve overall health and well-being.

The health benefits from eating pistachios may also happen quickly. For example, this study found that it only takes six weeks of daily pistachio eating to start seeing possible eye health benefits. “It’s never too early to start to think about what you can do to support healthy aging,” Dr. Scott adds.

For more information about research on the health benefits of pistachios, visit https://americanpistachios.org/nutrition-and-health. 

About the Study
The study, funded in part by the American Pistachio Growers and supported by National Institutes of Health’s National Center for Advancing Translational Sciences under award number UM1TR004398, involved 36 healthy adults who were randomly assigned to either a pistachio consumption group or a control group. Participants in the pistachio group consumed 2 ounces of pistachios daily, while the control group maintained their usual diets without pistachios. MPOD and blood levels of lutein were measured at baseline, six weeks, and 12 weeks. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

About American Pistachio Growers
American Pistachio Growers is a non-profit trade association representing more than 830 members who are pistachio growers, processors and industry partners in California, Arizona, Texas and New Mexico. American-grown pistachios are sold under many quality brand names internationally, so look for country of origin on packaging. For more information, visit AmericanPistachios.org.

Contact
Amber Wilson, MS, RD
Director, Nutrition Research and Communication
[email protected] 
 (310) 384-4251

References:

1. Scott TM, et al. Pistachio consumption increases Macular Pigment Optical Density in healthy adults: a randomized controlled trial. Journal of Nutrition. Published online October 17, 2024. DOI: 10.1016/j.tjnut.2024.10.022.
2. FoodData Central, FDC ID: 170185. USDA website. https://fdc.nal.usda.gov/fdc-app.html#/food-details/170185/nutrients. Accessed October 9, 2024.
3. New Poll Places Fear of Vision Loss at the Top of Americans' Health Concerns. Research to Prevent Blindness website. https://www.rpbusa.org/rpb/news-and-publications/news/latest/page-66/. Accessed October 18, 2024.
4. Prevalence Estimate for Age-Related Macular Degeneration (AMD). CDC website. https://www.cdc.gov/vision-health-data/prevalence-estimates/amd-prevalence.html. Published May 15, 2024. Accessed October 9, 2024.
5. Nutrient Intakes from Food and Beverages: Mean Amounts Consumed per Individual, by Gender and Age, What We Eat in America, NHANES 2017-2018. USDA website. www.ars.usda.gov/nea/bhnrc/fsrg. Accessed October 9, 2024.
6. Stringham JM, Johnson EJ, Hammond BR. Lutein across the lifespan: From childhood cognitive performance to the aging eye and brain. Curr Dev Nutr. 2019;3(7):nzz066.
7. Yagi A, Nouchi R, Butler L, Kawashima R. Lutein has a positive impact on brain health in healthy older adults: A systematic review of randomized controlled trials and cohort studies. Nutrients. 2021;13(6):1746.
8. Mandalari G, Barreca D, Gervasi T, Roussell MA, Klein B, Feeney MJ, Carughi A. Pistachio nuts (Pistacia vera L.): Production, nutrients, bioactives and novel health effects. Plants. 2021;11(1):18.

SOURCE American Pistachio Growers