Pistachio - Pistacia vera

Common Names: Pistachio, Pistachio nut, Green almond, Happy nut, Smiling pistachio, Pistacia vera, Pistachia, Pistazie, Pistazienbaum, pistache, pistacho, pistache tree, le pistachier, pistachier commun, pistachier vrai, pistachier cultivé, il pistacchio, alfóncigo, alfónsigo pistachero, pimpernoot, Harilik Pistacia

Latin Name: Pistacia vera

Origin: Africa, Asia, Australia, Europe, South America, North America

Short Introduction

Pistachio is a desert plant that tolerates saline soils very well. Pistachio trees are quite hardy and can survive temperature ranges from -10°C in winter up to about 48°C in summer. Pistachio trees need a sunny environment with well-drained soil.

The tree does not thrive in high humidity. Roots are extremely susceptible to fungal diseases if exposed to heavy winter watering and poorly drained soils. Long, hot summers are required for proper fruit ripening. Pistachios are famed for surviving extreme heat.

The quality and quantity of pistachio yields can vary by growing location. One of the most optimal regions is said to be Kerman Province in Iran, boasting average rainfall of 99.5 mm, high sunshine, cold winters, hot summers, and an average elevation of 1,600 meters. Pistachio trees require a pronounced winter chill for satisfactory dormancy and subsequent flowering.

Pistacia vera is hardy and tolerant of freezing temperatures, capable of surviving winter conditions down to -13°C to -15°C. In the Czech Republic, several growers near Olomouc, Brno, and elsewhere successfully cultivate pistachios in the open ground without protection from moisture or frost. Both domestic and international literature note pistachio hardiness to about -13°C to -15°C. In Czech conditions, trees can reach 1.5–2.5 meters in height and up to 2 meters wide. Young plants can be grown in smaller pots; mature plants may be kept in 20-liter containers.

Pistachio is very undemanding to cultivate. It can grow in deep, fertile soil as well as in rocky, poor soil, but it absolutely requires a consistently sunny, open site and dislikes constantly waterlogged ground.

Pistachio begins flowering at 6–7 years of age, or 2–3 years for grafted plants. Grafted trees are preferred for known gender, faster flowering, and better harvests. It is advisable to plant four or more trees to increase the likelihood of having both sexes. Pistachios are dioecious: one male tree can pollinate up to twelve female trees. Good and poor yields alternate annually.

Pistachio trees achieve peak production after about 20 years. Taller trees are pruned for easier harvesting. Every two years, a pistachio tree can produce up to 50,000 seeds, yielding around 50 kg on average. Harvest is typically biennial or irregular, with seeds shaken off the trees, sun-dried on the ground, and then sorted.

China is now the world's largest pistachio consumer, with annual consumption of 80,000 tons—about twice the rate of the USA.

Detailed Description

Pistachio is a globally recognized delicacy, acclaimed for its excellent effects on the human body.

Botanical Information

The pistachio tree is a shrub-like tree that can reach up to 10 meters in height and spread up to 30 meters wide, with a lifespan of up to 400 years. Pistachio trees have deciduous, needle-like leaves about 10–20 cm long. The trees are dioecious, meaning there are separate male and female plants. The flowers are petal-less, unisexual, and always located at the tips of the branches.

The fruit is a drupe containing a long, edible seed. While this seed is considered a nut culinarily, botanically it is not a true nut. The fruit features a firm, hard, creamy outer shell and grows in clusters. The seed has a gray-pink skin and greenish flesh, imparting the characteristic flavor.

When the fruit ripens, the shell typically changes from green to a yellow-red autumn color and suddenly partially splits open—a process called dehiscence—which is the natural opening of the fruit to release the seed.

Origin and Distribution

The pistachio as we know it today was likely first cultivated in Central Asia during the Bronze Age, with the earliest finds originating from Djerkutane in modern Uzbekistan. The tree originates from Central Asia or the Middle East. Today, the world's largest producers of pistachios are Iran, the United States, and Turkey, with smaller quantities grown in China, Syria, and Greece.

Pistachio trees are now found throughout all warm subtropical areas worldwide. Wild pistachios can still be found in the mountains of Afghanistan and Iran, growing from 500 to 2,000 meters above sea level.

Usage / Dosage

Archaeological finds indicate pistachios were known as early as 6750 BCE. Ancient historians documented that pistachios were introduced to Italy from Syria by Roman Proconsul Lucius Vitellius in 35 CE and, in the same year, to Hispania by Flaccus Pompeius.

Pistachios thus made their way into Europe from Western Asia, either through Ancient Greece or Rome. The plant's name likely originates from ancient Persian ('pesteh'), and evolved through Greek ('pistakion', 'pistake'), Latin ('pistacium'), and early Italian ('pistacchio'). The earliest record in English literature dates to around 1400, with spellings such as pistace and pistacia.

Commercially, pistachios were first grown in the English-speaking world in Australia, New Mexico, and California, starting around 1854. In 1917, W.T. Swingle introduced pistachio cultivation along the Nile, and by 1929, new varieties were being grown from China to California.

Pistachio trees are cultivated for their edible seeds, known as pistachios, which can be eaten fresh, roasted, or as ingredients in other products. Pistachio ice cream, Turkish delight (lokum), and mortadella sausage are particularly popular. Baklava—a Mediterranean pastry—often features pistachio or almond flavorings. The most widespread and popular cultivar is “Kerman.”

Pistachios are used in desserts like kulfi and spumoni, as well as Neapolitan ice cream, pistachio butter, pastes, and confections such as baklava, halva, chocolate, Turkish delight, and sponge cakes. In America, pistachio salad, which includes pistachio pudding, cream, and candied fruit, is a popular dish.

Pistachios are renowned for their ability to reduce appetite, a valuable trait for those seeking weight loss. They have a distinctive taste and appealing green color, which in China has earned them the nickname “happy nut” and in Iran, “smiling pistachio.”

Experts recommend pistachios as a regular snack for people wishing to lose weight since they are low in calories and create a lasting sense of fullness. A serving typically includes about 50 pistachios, equaling approximately 170 calories. While pistachios are an ideal diet food, portion control is advised for certain individuals.

Studies suggest that pistachios may help reduce LDL cholesterol. One study with a small group found LDL levels dropped by an average of 14% and HDL levels rose by 25% when participants obtained 20% of their calories from pistachios. With a balanced diet, pistachios can help lower and delay the risk of developing heart disease.

Pistachios are rich in antioxidants. Carotene, lutein, vitamin E, and certain polyphenols help eliminate free radicals. Lutein, in particular, helps protect cells from LDL cholesterol oxidation, reduces inflammation, and appears vital for reducing the risk of heart disease.

Clinical assessment has supported the possible use of pistachios in managing hypercholesterolemia. A clinical study involving both healthy volunteers and individuals with moderate hypercholesterolemia showed improvements in lipid profiles following consumption of unsalted pistachio seeds.

Research has shown reduced total cholesterol, decreased LDL, and increased HDL cholesterol. No significant changes were noted in triglyceride or blood pressure levels. Some studies observed positive changes in apolipoprotein levels and acute effects after two doses, while others documented benefits with long-term (3-week) regular consumption.

In 2003, the FDA (Food and Drug Administration) approved the claim that daily consumption of about 43g of most nuts, as part of a dietary plan, may reduce the risk of heart disease.

Extracts from pistachio plants and seeds have shown mild in vitro effects against human bacterial pathogens compared to the antifungal agent nystatin. Extracts from fresh, shell-on Turkish pistachios also demonstrated antiviral activity against the herpes simplex virus when compared to acyclovir.

The antioxidants in pistachios can prevent glycation, which can help manage diabetes. Water and ethanol extracts of pistachio leaves and seeds exhibited antioxidant activity thanks to their flavonoid and tannin content in broad in vitro studies.

Zeaxanthin and lutein found in pistachios may help prevent eye-related diseases and are widely recommended for preventing macular degeneration, a condition that can lead to blindness or vision problems over time.

Pistachio oil is also used for its skin moisturizing properties. It is a favorite emollient in cosmetics for its fragrance (also valued in aromatherapy) and effects.

Alternative Medicine

In traditional Chinese medicine, the whole pistachio tree is used for abdominal pain, amenorrhea, burns, abrasions, dysentery, gynecological issues, pruritus, rheumatism, liver disorders, ulcers, and trauma. The seeds are used as sedatives and tonics.

Pistachios are also regularly used to relieve uncomfortable and painful sensations and as a remedy for acute and chronic inflammation with dose-dependent analgesic effects.

Interestingly, pistachios are highly flammable and should not be stored in bulk, as they may spontaneously combust. Like related plants in the same family, pistachios can cause allergies in some people.

Active Compounds

One hundred grams of pistachios contain about 562 calories and are a rich source of protein, fiber, minerals (calcium, magnesium, iron, manganese, phosphorus, potassium, and zinc), and vitamins (A, B1, B2, B3, C, B5, B6, B12, E, D, folate), as well as saturated (palmitic and stearic acids) and unsaturated fatty acids (oleic and linoleic acids).

Pistachios contain copper, vitamin B6, and manganese—essential for bone and tissue development, and fat and carbohydrate metabolism. The seeds are additionally rich in fiber, supporting healthy digestion.

Pistachio fruits are high in protein, oil, and vitamin E compared to hazelnuts. Unsalted pistachios are rich in potassium and low in sodium, and their kernels are abundant in linoleic and linolenic fatty acids. Additional antioxidants in pistachios include alpha and gamma tocopherol, vitamin C, proanthocyanidins, trans-resveratrol, daidzein, genistein, and isoflavones.

Traditional Dosage

Dosage varies according to needs and tradition. To achieve the recommended daily intake of antioxidants, protein, and minerals, a handful of pistachios is considered optimal. The precise dose depends on individual study goals.

For improvement of lipid profiles, it is recommended that pistachios make up about 20% of daily caloric intake. Some studies suggest a daily dose of 65–75 grams per adult, while others use up to 125 grams per day.