A recent study led by Dr. Tammy Scott, a research and clinical neuropsychologist from Tufts University, has found that daily consumption of pistachios may significantly improve eye health and cognitive function. The study observed that adults who included two ounces of pistachios daily for 12 weeks showed better improvements in eye health compared to those on a regular diet, significantly increasing the optical density of the macular pigment (MPOD).
The research was conducted on 36 healthy adults aged between 40 and 70 years, with a diet consisting of low amounts of lutein-rich foods. Participants were divided into two groups: one group added about 60 grams (two ounces) of unsalted pistachios to their diet, while the other group continued their normal diet. After 12 weeks, participants who consumed pistachios had a significant increase in macular pigment optical density, while the control group that did not consume pistachios showed no changes in eye health.
The increase in MPOD is attributed to lutein, a key plant pigment that protects the eyes from visible blue light and age-related damage, and plays a fundamental role in maintaining eye health. MPOD is an important indicator of eye health that protects the retina and is linked to a lower risk of age-related macular degeneration (AMD), a leading cause of blindness in older adults. By increasing MPOD, pistachios may help reduce the risk of AMD.
Lutein, present in pistachios, plays a fundamental role in maintaining eye health by filtering blue light, acting as an antioxidant, and helping to prevent age-related macular degeneration. Lutein also protects the eyes against blue light emitted by computers and cell phones, which can cause damage to ocular cells. By protecting the eyes, lutein helps to prevent cataracts and reduces the risk of age-related macular degeneration.
The study revealed that daily consumption of pistachios nearly doubled the daily intake of lutein among participants, with approximately 1.6 mg of lutein obtained from the pistachios consumed. This amount of lutein is usually very low in most American diets. Although green leafy vegetables are usually the preferred dietary source of lutein, containing more lutein than pistachios, pistachios provide a significant amount and are the only nuts that contain lutein. A serving of spinach contains 7 mg of lutein, while a serving of pistachios contains only 1.6 mg. However, pistachios contain natural fat content that helps the body absorb lutein more effectively, significantly improving eye health.
Tammy Scott stated, "By simply incorporating a handful of pistachios into your diet, you can improve your lutein intake, which is crucial for protecting your eyes."
In addition to eye health benefits, lutein present in pistachios may also benefit brain function. Lutein crosses the blood-brain barrier, where it may help reduce oxidative stress and inflammation. Lutein may play a role in reducing cognitive decline. Studies suggest that higher lutein levels are associated with better cognitive performance, including memory and processing speed. Similar to its action in the eyes, lutein selectively accumulates in the brain.
Pistachios also provide other known health benefits. They are rich in healthy fats, protein, and dietary fiber. Pistachios provide essential amino acids, especially arginine, which is a precursor of nitric oxide that helps dilate blood vessels and improve blood flow. Daily consumption of pistachios can have a positive effect on body weight control. Although pistachios are energy-dense due to their healthy fat content, moderate consumption does not contribute to weight gain and may even help with weight loss in some cases. Pistachios are rich in proteins, fiber, and healthy fats, which create a prolonged feeling of satiety, reducing the intake of other foods and controlling appetite.
The study suggests that regular consumption of pistachios could offer a natural dietary approach to reduce the risk of AMD and supports overall healthy aging. Pistachios are a valuable addition to a diet aimed at promoting healthy aging overall.
The study has several limitations, including a small sample size. The study focused only on healthy adults. The daily dosage of pistachios in the study was relatively high. Researchers recommend consuming about 60 grams of pistachios per day, which is approximately 50-100 kernels. The regular daily recommendation of pistachios is 45 grams. Although the lutein content in pistachios is lower than in some vegetables, the efficient absorption allows reaching the recommended lutein intake of 6 mg per day.
The study was partially funded by the American Pistachio Growers Association. The funding did not have an effect on the results.
Daily consumption of pistachios may protect eye health and prevent age-related vision problems, as they contain lutein, which plays a fundamental role in maintaining eye health. By incorporating pistachios into the diet, individuals may improve their lutein intake, which is crucial for protecting the eyes and supporting cognitive function.
Sources: La Voz, El Economista, O Globo, Diario de Sevilla, Alghad
This article was written in collaboration with generative AI company Alchemiq