Pistachios

Pistachios are the seeds of the pistachio tree. They’re usually green and slightly sweet. They’re called nuts, but botanically pistachios are seeds. The kernels can have different colors, ranging from yellow to shades of green. They’re usually about an inch long and half an inch in diameter.

Pistachios have been consumed by humans for about 9,000 years and are one of two nuts (the other is the almond) mentioned in the Bible. Interestingly, pistachios are botanically related to the mango and cashew nut (so if you have an allergy to one, you may be allergic to the others). In Iran, which is one of the world’s largest pistachio producers, the pistachio is called the “smiling nut,” and in China, it’s referred to as the “happy nut,” due to the nut’s open-mouthed appearance when the shell is cracked.

Most nuts like pistachios contain large amounts of protein relative to their size. A 1-ounce serving of these nuts, approximately 50 pistachio kernels,  contains 6 grams of protein.

According to the United States Department of Agriculture (USDA), 1 ounce or approximately 49 kernels of unroasted nuts contain:

• Calories: 159
• Protein: 5.72 grams
• Fat: 12.85 g
• Carbohydrates: 7.70 g
• Fiber: 3.00 g
• Sugars: 2.17 g
• Magnesium: 34 milligrams (mg)
• Potassium: 291 mg
• Phosphorus: 139 mg
• Vitamin B-6: 0.482 mg
• Thiamin: 0.247 mg

Vitamin B6 has many health benefits. Failure to get enough vitamin B6 has been associated with elevated risk of cardiovascular disease, certain types of cancer, and cognitive dysfunction. Getting vitamin B6 into your diet may improve your cardiovascular health and keep your brain sharp. Women need 1.5 mg of vitamin B6 per day, while men need 2 mg per day. A 1-ounce serving of pistachios contains 0.4 mg.

Protein accounts for approximately 21 percent of the total weight of the nut, making it a good source for vegetarians and vegans. Pistachios also have a higher ratio of essential amino acids, the building blocks of protein, when compared with other nuts, including almonds, hazelnuts, pecans, and walnuts.

Pistachios are a high-fat food, but that is not a bad thing. Per serving, pistachios contain 13 total grams of fat. However, only 2 grams of fat are saturated fats, the unhealthy fats that are associated with higher risk of cardiovascular disease. The rest of the fats are polyunsaturated and monounsaturated fats, which actually protect the heart.

This includes omega-3 fatty acids, a type of fat that is good for cholesterol control.  Pistachios contain alpha-linoleic acid (ALA), a beneficial type of omega-3 fatty acid that can also be converted to DHA and EPA, the two other forms of omega-3s that are only found in animal sources.

Pistachios are an excellent source of antioxidants, including lutein, beta-carotene, and gamma-tocopherol. Beta-carotene serves as a precursor to vitamin A, while gamma-tocopherol is used as a precursor to vitamin E.  Both vitamin A and vitamin E have very high antioxidant activity. In a randomized study of the effects of pistachios, researchers found that incorporating these nuts into the diet was associated with lower levels of LDL cholesterol.

Pistachios have a low glycemic index, so they do not cause a sharp rise in blood sugar after eating them. In a small study of 10 people, eating pistachios reduced high blood sugar when eaten with a carbohydrate-rich meal, such as white bread. The researchers suggest that this is one of the ways that nuts lower the risk of diabetes.

For people with diabetes, another study suggests that eating pistachios as a snack is beneficial for blood sugar levels, blood pressure, obesity, and inflammation markers.

Although raw pistachios don’t have much sodium (1 cup has about 1 milligram), that’s not true for roasted pistachios, which are often salted. A cup of dry roasted pistachios with salt has 526 milligrams of sodium. Too much sodium can lead to high blood pressure, heart disease, and stroke.

How to Buy

When purchasing the nuts in their shells, look for blemish-free, ivory-colored shells that are split open at one end. Avoid pistachios that are cracked beyond their natural opening. Unopened shells are an indicator of immaturity. The kernel, or nutmeat, should be yellow to dark green in color. The greener the nutmeat, the better the flavor.

Unshelled and shelled pistachios are available in bags year-round in many forms, including raw, roasted, salted, unsalted, and seasoned. For cooking purposes, it is best to choose pistachios that have not been dyed either green or red, which is often done to cover up blemishes. (Luckily for us in the US, almost all domestically grown pistachios are sold without dye.)

Once you remove the shell, you’ll find the nut covered in a thin, edible paper that can be easily removed from the nutmeats by blanching, if desired. After parboiling, drain and slightly cool the pistachios before slipping off the skins.

How to Store

Since the shell splits upon ripening to expose the nutmeat, pistachios have a limited shelf life. If keeping the nuts for just a few days, you can place them in resealable bags and store in the pantry. For a longer storage period, place pistachios in an airtight container in the refrigerator or freezer. Unshelled nuts may be stored for three months in the refrigerator or up to one year in the freezer. To prevent condensation when thawing, place the nuts in an open bowl. Shelled pistachios can be stored in the refrigerator for up to three months but are not good candidates for freezing.

To refresh pistachios that have lost their crunch, toast them in a 200 F oven for 10 to 15 minutes.

How to Cook

Toss pistachios on a salad or in a smoothie or on oatmeal.

The following flavors are among the most compatible with pistachios:

• Chocolate
• Citrus: orange, blood orange, lemon, Meyer lemon
• Candied orange
• Orange blossom water and rose water
• Wildflower or orange blossom honey
• Dried fruits: dates, apricots, raisins
• Spices: saffron, cardamom, clove, sea salt, pink peppercorns