Article Highlight | 12-Oct-2023

Believe it or nut… New review paper in nutrients aims to set the record straight on nut protein quality

American Pistachio Growers

FRESNO, Calif., October 12, 2023 – A breakthrough new review paper, published in the journal Nutrients, is looking to set the record straight on the protein quality of nuts, through the example of pistachios. As the global population surges from 8 billion to a projected 9.7 billion people by 2050[1], plant-sourced protein will have an important role to play both in meeting protein demands and diversifying protein food options globally. 

There are growing public health movements to transition towards diets that are plant-based to improve both human and planetary health. However, confusion exists with concerns that plant-based proteins (including nuts) may be inferior with respect to protein quality. With this shift from animal- to plant-based proteins, the authors of this landmark review paper[2] suggest we take a fresh look at our definition of protein quality to move beyond the traditional methods —which focus on the amino acid makeup of proteins— and begin to extend that definition to include the health impact of a protein on people and the environment.

“Dietary guidelines are evolving as we transition towards more plant-based diets. We need to look at protein quality from the perspective of whole daily diets and dietary patterns, factoring in both health and environmental outcomes,” notes Dr. Emma Derbyshire BSc, PGCHE, PhD, RNutr, a scientific nutrition writer and the main author on the paper. “Given updated modes of thinking, nuts such as pistachios have an important role to play in terms of providing a nutrient-dense source of protein, ready-to-eat as a snack or meal addition and capable of contributing to future protein demands.”

Individual foods are not eaten in isolation and protein is no exception – it’s eaten in conjunction with other foods throughout the day. The authors of this new paper point out the importance of focusing on the overall diet pattern, rather than whether individual foods provide all nine essential amino acids. Each protein food that is eaten throughout the day —and the amino acids within that food— contribute to the overall protein quality of the diet. According to the authors, filling the daily diet with a mix of plant- protein options, alongside sufficient energy, helps to optimize protein quality overall.

Pistachios have a Protein Digestibility Corrected Amino Acid Score (PDCASS) of 73% and 81% (raw and roasted pistachios respectively)[3]. They deliver an array of nutrients and health-protective phytochemicals. In fact, a study[4] out of Cornell University found that pistachios are high in two measures of antioxidant activity, Oxygen Radical Absorbance Capacity (ORAC) and Cellular Antioxidant Activity (CAA), due to their phytochemical profile.

Pistachios can easily be eaten as a snack or incorporated into main meals to help meet protein needs throughout the day, as part of a balanced and varied diet and healthy lifestyle. Eating pistachios can bring promising health benefits, due to their nutrient density (i) and at the same time help to alleviate the pressure from other food protein production methods that may contribute more to environmental strains.

This review paper was supported by the American Pistachio Growers.

Notes to Editors

  1. Pistachios are high in fibre; potassium which contributes to maintenance of normal blood pressure; chromium which contributes to maintenance of normal blood glucose levels. Pistachios also provide a source of energy; protein, potassium & magnesium which help muscle maintenance; iron & folate which contribute to reduction of tiredness and fatigue; vitamins B1(thiamin), B2(riboflavin) & B6 which contribute to normal energy yielding metabolism; vitamin E, selenium, copper & zinc which contribute to protection of cells from oxidative stress.  Iron and zinc also contribute to normal cognitive function. Pistachios are high in unsaturated fats. Replacing saturated fats with unsaturated fats in the diet contributes to the maintenance of normal blood cholesterol levels. Pistachios contain 0.21g/100g plant sterols, which also contribute to maintaining normal blood cholesterol levels (beneficial effect is obtained with a daily intake of at least 0.8 g of plant sterols/stanols)

For more information on the research behind the health benefits of pistachios visit 


[1] UN World Population Prospects 2022:

[2] Derbyshire, E., Higgs, J., Feeney, M.J., et al. (2023). Believe It or ‘Nut’: Why It Is Time to Set the Record Straight on Nut Protein Quality: Pistachio (Pistacia vera L.) Focus. Nutrients, 15(9), 2158. MDPI AG.

[3] Bailey, H. M., & Stein, H. H. (2020). Raw and roasted pistachio nuts (Pistacia vera L.) are ‘good’ sources of protein based on their digestible indispensable amino acid score as determined in pigs. Journal of the Science of Food and Agriculture100(10), 3878-3885.

[4] Yuan, W., Zheng, B., Li, T., & Liu, R. H. (2022). Quantification of Phytochemicals, Cellular Antioxidant Activities and Antiproliferative Activities of Raw and Roasted American Pistachios (Pistacia vera L.). Nutrients, 14(15), 3002.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.