Pistachios as Part of a Healthy Diet

When it comes to healthy eating, multiple studies have concluded that eating pistachios may be correlated with improved nutrition status and overall health and wellbeing. Pistachios’ unsaturated fatty acids (e.g., MUFA and PUFA), protein, dietary fiber, magnesium, potassium, vitamin K, and phytochemicals - such as phytosterols, lutein (xanthophyll carotenoid), g-tocopherol, and polyphenols - may act synergistically to help promote cardiovascular health, glycemic control, and weight maintenance when eaten as part of a healthy diet. Moreover, some research shows that tree nut consumption is associated with reduced total and cause-specific mortality.

[Bao, Y., et al. Association of nut consumption with total and cause-specific mortality. N Engl J Med. 2013;369:2001-2011.]

Below you’ll find a handful of recent studies on pistachios and healthy eating.

Baer DJ, Gebauer SK, Novotny JA. Measured energy value of pistachios in the human diet. Br J Nutr. 2012;107(1):120-5.

Sixteen men and women between the ages of 29 and 64 ate either 0, 1.5 or 3 ounces of pistachios per day as part of a controlled diet.
Blood, urine and feces were collected. Calculations showed that the actual calories used from the pistachios were lower than what was previously thought.
The authors speculate that the dietary fat content of nuts may be resistant to absorption.

Ballistreri G, et al. Influence of ripeness and drying process on the polyphenols and tocopherols of Pistacia vera L. Molecules. 2009;14(11):4358-69.

Changes in the phenolics fraction (anthocyanins, flavonoids and stilbenes) and tocopherols of unpeeled pistachios with ripening, and the effect of the sun-drying process are investigated.
Total polyphenol levels increased with ripening, while the sun drying process caused a susbtantial loss.
These results suggest that unpeeled pistachios can be considered an important source of phenolics, particularly of anthocyanins. Moreover, in order to preserve these healthy characteristics, new and more efficient drying processes should be adopted.

Berk L, et al. Nuts and Brain Health: Nuts Increase EEG Power Spectral Density (μV&[sup2]) for Delta Frequency (1–3Hz) and Gamma Frequency (31–40 Hz) Associated with Deep Meditation, Empathy, Healing, as well as Neural Synchronization, Enhanced Cogn. FASEB, 2017

In this pilot study researchers assessed the strength of brain wave signals using electroencephalograms (EEG) to study the relationship between eating different types of nuts (walnuts, pecans, peanuts (a legume), pistachios, cashews, and almonds) and sensory awareness tests.
Pistachios produced the highest response to gamma waves, associated with thinking, integrating thoughts and processing information. Although the exact nutrient/compounds and mechanisms are not yet known, results suggested that nuts are associated with brain wellness perhaps due to their antioxidant and anti-inflammatory properties.

Bolling BW, et al. Tree nut phytochemicals: composition, antioxidant capacity, bioactivity, impact 1 factors. A systematic review of almonds, Brazils, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios, and walnuts. Nutr Res Rev. 2011;24(2):244-75.

Summarizes the current knowledge of the carotenoid, phenolic, and tocopherol content of tree nuts and associated studies of the antioxidant actions in vitro and in human studies.
Tree nuts are a rich source of tocopherols and total phenols and contain a wide variety of flavonoids and proanthocyanidins. In contrast, most tree nuts are not good dietary sources of carotenoids and stilbenes.
Phenolic acids are present in tree nuts but a systematic survey of the content and profile of these compounds is lacking. A limited number of human studies indicate these nut phytochemicals are bioaccessible and bioavailable and have antioxidant actions in vivo.

Bolling BW, et al. The phytochemical composition and antioxidant actions of tree nuts. Asia Pac J Clin Nutr. 2010;19(1):117-23.

While tree nut phytochemicals are bioaccessible and bioavailable in humans, the number of intervention trials conducted to date is limited.
This review summarizes tree nut: (1) phytochemicals; (2) phytochemical content included in nutrient databases and current publications; (3) phytochemicals affected by pre- and post-harvest conditions and analytical methodology; and (4) bioactivity and health benefits in humans.

Brown R, et al. Associations between nut consumption and health vary between omnivores, vegetarians, and vegans. Nutrients. 2017 Nov; 9(11): 1219. doi: 10.330-/nu9111219.

This study examined the relationships between nut intake and disease risk factors in the UK Women’s Cohort Study, a large sample size having diverse dietary patterns. Participants self-identified as omnivores, vegetarians and vegans and reported nut intake on a food frequency questionnaire.
Higher nut intake was associated with lower body weight, body mass index, and waist circumference. Higher nut consumption was also associated with a reduced prevalence of high cholesterol and blood pressure, having a history of heart attack, diabetes and gallstones; and markers of diet quality. Higher nut consumption appeared overall to be associated with greater benefits among omnivores compared to vegetarians and vegans.

Carey AN, et al. The beneficial effects of tree nuts on the aging brain. Nutr Aging. 2012;1:55-67.

Evidence is accumulating that suggests tree nuts and their bioactive constituents have the potential to reduce oxidative stress and inflammation, as indicated by decreased lipid peroxidation in vivo and reduced production of the free radical nitric oxide and the pro-inflammatory cytokine tumor necrosis factor-alpha in vitro.
Also, tree nut consumption might have the ability to mitigate some of the cognitive decline associated with aging.
The current knowledge of how the consumption of nuts may improve brain health is reviewed, specifically focusing on walnuts, almonds, pistachios, and pecans.

Dreher ML. Pistachio nuts: composition and potential health benefits. Nutr Rev. 2012;70(4):234-40.

This review examines the nutrients and phytochemicals in pistachios as well as the potential health effects of these nuts.
A growing number of clinical studies from around the world suggest potential health benefits of several varieties of pistachio nuts.
Five published randomized clinical studies have shown that pistachios have a beneficial effect on blood lipid profiles. Emerging clinical evidence suggests that pistachios may help reduce oxidative and inflammatory stress and promote vascular health, glycemic control, appetite management, and weight control.

Halvorsen BL, et al. Content of redox-active compounds (i.e., anatioxidants) in foods consumed in the United States. Am J Clin Nutr. 2006;84(1):95-135.

Aimed to generate a ranked food table with values for total content of redox-active compounds to test this alternative antioxidant hypothesis.
Analyzed 1,113 food samples obtained from the US Department of Agriculture National Food and Nutrient Analysis Program.
Large variations in the content of antioxidants were observed in different foods and food categories. Pistachios were among the 50 foods with the highest antioxidant content.

Mandalari G, et al. Bioaccessibility of pistachio polyphenols, xanthophylls, and tocopherols during simulated human digestion. Nutr. 2013;29(1):338-44.

Quantified the release of polyphenols, xanthophylls (lutein), and tocopherols from pistachios (raw pistachios, roasted salted pistachios, and muffins made with raw pistachios) during simulated human digestion.
More than 90% of the polyphenols were released in the gastric compartment, with virtually total release in the duodenal phase. No significant differences were observed between raw shelled and roasted salted pistachio.
The rapid release of the assayed bioactives in the stomach maximizes the potential for absorption in the duodenum and contributes to the beneficial relation between pistachio consumption and health-related outcomes.

Martorana M, et al. In vitro antioxidant and in vivo photoprotective effect of pistachio (Pistacia vera L., variety Bronte) seed and skin extracts. Fitoterapia. 2013;85:41-48.

Investigated the chemical composition and antioxidant properties of two polyphenol-rich extracts from skins (TP) and decorticated seeds (SP) of Bronte pistachios, and to verify the potential use of these extracts for topical photoprotective products.
Both of these extracts, and especially the TP extract, possess good radical scavenger/antioxidant properties, as shown in a series of in vitro assays carried out using homogenous and non-homogenous chemical environments.
Findings suggest that extracts from Bronte TP and SP could be successfully employed as photoprotective ingredients in topical cosmetic and pharmaceutical formulations.

O’Neil, C, et al. Tree nut consumption is associated with better nutrient adequacy and diet quality in adults: national health and nutrition examination survey 2005–2010. Nutrients. 7:595-607.

The National Health and Nutrition Examination Survey 2005–2010 data were used to assess the association of tree nut consumption by adults 19+ years (n = 14,386) with nutrient adequacy and compare the diet quality of those who consume tree nuts (including pistachios), and non-tree nut consumers in a nationally representative population.
The data showed that, compared to non-consumers, tree nut consumers had a lower percentage of the population consuming usual intakes of nutrients below the recommended levels of vitamins A, E and C, folate, calcium, iron, magnesium, and zinc. Tree nut consumers had a higher percentage of the population over the recommendation for adequate intake for dietary fiber and potassium. The Healthy Eating Index-2005, an objective measure of diet quality, was significantly higher in tree nut consumers than non-consumers.
Tree nut consumption was associated with better nutrient adequacy for most nutrients that are lacking in the diets of many Americans, and with better diet quality.

Pérez-Jiménez J, et al. Identification of the 100 richest dietary sources of polyphenols: an application of the Phenol-Explorer database. Eur J Clin Nutr. 2010;64:S112-20.

Contents of individual polyphenols have been determined by chromatography. These data, scattered in several hundred publications, have been compiled in the Phenol-Explorer database.
The aim of this paper is to identify the 100 richest dietary sources of polyphenols using this database.
Pistachio made the list of the 100 richest dietary sources of polyphenols.

Seeram NP, et al. Pistachio skin phenolics are destroyed by bleaching resulting in reduced antioxidative capacities. J Agric Food Chem. 2006;54:7036-40.

Raw nuts preserved phenolic levels and antioxidant capacity better than roasted nuts, suggesting contributing effects of other substances and/or matrix effects that are destroyed by the roasting process.
The destruction of bioactive phenolics in pistachio skins may negatively impact the potential health benefits arising from pistachio consumption.

Tomaino A, et al. Antioxidant activity and phenolic profile of pistachio (Pistacia vera L., variety Bronte) seeds [kernels] and skins. Biochimie. 2010;92(9):1115-22.

The antioxidant activity of pistachio seeds [kernels] and skins were determined by means of four different assays.
Pistachio skins have shown to possess a better activity with respect to seeds [kernels] in all tests.
The excellent antioxidant activity of pistachio skins can likely be explained by its higher content of antioxidant phenolic compounds.