Pistachios are one of the world’s oldest nuts. They have been grown in the Middle East for thousands of years. These little green nuts have a delicious, slightly sweet flavor and are a great source of nutrition. A diet that incorporates a daily dose of pistachios can provide many health benefits, including improved gut health, lower risk for cancer, and weight loss.
What are pistachios?
Pistachio (Pistacia vera) is a member of the cashew family. Pistachios grow in clusters on small, bushy, deciduous trees, which can reach to the height of 25 to 30 feet. These nuts start as yellow or reddish fruits. When they ripen, the shells natural burst along the seam to reveal the seed inside. The nuts are harvested by shaking the pistachios from the branches and catching them on a tarp. Pistachio nuts are oblong green colored seeds that are nestled in cream-colored shells.
History of pistachios
Pistachios originated in western Asia and the Middle East. According to archeological evidence from Turkey, these nuts were being used as food as early as 7000 BC. Pistachios were introduced to Italy from Syria in the first century AD. Later its cultivation spread to other Mediterranean countries.
According to a legend, the Queen of Sheba decreed pistachios to be exclusively royal food. Commoners were forbidden from growing pistachios for personal use. Nebuchadnezzar, the king of Babylon, has pistachio trees in his hanging gardens.
Pistachios were an essential travel item among early explorers and traders thanks to their high nutritional value and long storage life. Travelers frequently carried them across the ancient silk route that connected China with the West.
The pistachio tree was introduced to the US by Charles Mason in 1854. He distributed seeds for experimental planting in California, Texas, and other southern states. In 1875 a few pistachio trees were imported from France and planted in Sonoma, Calif. The US Department of Agriculture assembled a collection of Pistacia species and pistachio nut varieties at the Plant Introduction Station in Chico in the early 1900s. The commercial production of pistachio nuts in the US began in the 1970s.
Nutritional profile of pistachios
According to the US Department of Agriculture (USDA) one ounce (49 kernels)of pistachios contain (1) –
- Calories: 159
- Carbohydrates: 8 grams
- Fiber: 3 grams
- Protein: 6 grams
- Fat: 13 grams
- Potassium: 291 mg (6% of RDI)
- Phosphorus: 139 mg (11% of RDI)
- Vitamin B6: .482 mg (28% of DRI)
- Copper: .36 mg (41% of RDI)
- Thiamine: .247 mg (21% of RDI)
- Manganese: .33 mg (15% of RDI)
Health benefits of pistachios
1. Rich in antioxidants
Several studies have assessed the antioxidant capacity of pistachios and shown that they contain a range of antioxidant compounds that provide benefits like anti-inflammatory and antimicrobial activity, slowing down brain aging and preventing heart disease.
Pistachios have the highest levels of several antioxidants, like γ-tocopherol, phytosterols, and xanthophyll carotenoids (2). According to a 2010 study, when 28 participants with high cholesterol ate one or two servings of pistachios for four weeks, they experienced an increase in the levels of lutein, α-carotene, and β-carotene (3).
The antioxidant compounds in pistachios are readily available for the body to use. A study published in Nutrition showed that the polyphenols, xanthophylls, and tocopherols in pistachios are more than 90 % bioaccessible (4).
2. Good for eye health
Pistachios are the only nut that contains a significant amount of lutein and zeaxanthin, which are essential for eye health. According to the American Optometric Association, carotenoids like lutein and zeaxanthin reduce the risk of chronic eye diseases like AMD and cataracts (5).
Pistachios also contain monounsaturated fats, which help boost the absorption of carotenoids. Pistachios are also an excellent source of vitamin E, which is known to decrease the risk of age-related macular degeneration, cataracts, and other vision problems. Some studies have also shown that vitamin E can reduce diabetic retinopathy, a diabetes-related vision problem.
3. Low in calories
While most nuts are high in nutrition, they also pack in several calories. Fortunately, pistachios are one of the lowest-calorie nuts. One ounce of macadamia nuts contains 204 calories, one ounce of pecans contains 196 calories, while one ounce of pistachios contains only 159 calories. This means you can enjoy these nuts without worrying about their calorie content.
4. Good for digestive health
Pistachios are rich in fiber, which plays a vital role in digestive health. Fiber helps to move food through the gut and prevent constipation. Some fibers act as prebiotics and feed the good bacteria to crowd out harmful bacteria from the stomach.
During a 2012 study, human volunteers ate either 0, 1.5, or 3 ounces of pistachios or almonds per day. The results showed that the effect of pistachios on the microbiota was much stronger than that of almonds and included an increase in butyrate-producing bacteria in the phylum Firmicutes (6).
5. Reduces the risk of heart disease
According to a 2008 study from Penn University, eating a healthy diet with pistachios can lower bad cholesterol by 12 % and reduce the risk of coronary heart disease by 9 to 12 % (8). Pistachios also help to lower blood pressure. During a systematic review of 21 studies, researchers discovered that eating pistachios has the most potent effect in reducing systolic blood pressure and diastolic blood pressure (9).
6. Promote healthy blood sugar levels
According to new research, pistachio is a balanced diet that can lower the risk of developing Type 2 diabetes. Eating pistachio may help lower blood sugar and insulin levels and reverse some prediabetes indicators according to a study published in Diabetes Care.
According to a 2011 study from Toronto, when healthy volunteers were given 56 grams of pistachios with high carbohydrate foods, it significantly reduced postprandial glycemia (10). Pistachios are a great source of antioxidants, carotenoids, and phenolic compounds, which are highly beneficial for blood sugar control (11).
7. Lowers colon cancer risk
Pistachios can also help reduce the risk of certain cancers like colon cancer. According to a 2017 study, pistachios are rich in health-promoting bioactive compounds such as B vitamins, y-tocopherol polyphenols, and dietary fiber, which could contribute to the reduction of colon cancer risk (12).
8. Helps in weight loss
Pistachios are beneficial for weight loss as they are rich sources of protein and fiber and are low in calories. Fiber keeps you full for longer, and this prevents you from binging on unhealthy foods. Protein keeps you satiated and keeps hunger pangs at bay.
During a 2010 study, participants on a 12-week weight reduction diet were given either 53 grams of salted pistachios or 56 grams of salted pretzels. The results show that the group that ate pistachios had twice the reduction in body mass index as compared to the group that ate pretzels (13).
Fats from nuts are more poorly absorbed than other foods. This may also help in weight loss. Shelling pistachio nuts takes time, which can slow down the rate at which you eat them. Also, the empty shells give a visual reminder to the number of pistachios you have eaten and help in reducing overconsumption (14).
9. Promote blood vessel health
The inner lining of blood vessels is called the endothelium. An endothelium dysfunction, which is characterized by reduced dilation of blood vessels, is a risk factor for heart disease. Nitric oxide plays a vital role in vasodilation as it causes blood vessels to dilate by signaling the cells in the endothelium to relax.
Pistachios are an excellent source of L-arginine, which is converted into nitric oxide in the body, which is why they play an essential role in promoting blood vessel health. During one study, 32 healthy young men ate a Mediterranean diet with 20 percent of daily calorie intake from pistachios for four weeks. The results showed that the pistachio diet significantly improved endothelium-dependent vasodilation by 30 percent (15).
Pistachios are an excellent source of protein for vegetarians. A one-ounce serving of pistachios provides six grams of protein (16). Almost 20 percent of the weight of pistachios comprises proteins. Pistachios also have a higher ratio of essential amino acids when compared to other nuts.
11. Support brain health
Pistachios are a rich source of vitamin E, which plays an essential role in preventing age-related cognitive decline. According to researchers from Loma Linda University Adventist Health Scientist Centre, eating nuts like pistachios strengthens brainwave frequencies associated with cognition, memory, healing, learning, and other essential brain functions (17).
During another animal-based study, researchers found that including pistachios in your diet following anticancer drugs such as cisplatin and vincristine has a protective effect against anticancer drug-induced disruptions in motor and cognitive function (18).
Side effects of eating too many pistachios
While pistachios are healthy, eating too many of these nuts can lead to some side effects. People who are allergic to tree nuts should avoid pistachios as they may be allergic to pistachios also. The common symptoms of tree nut allergies are abdominal pain, diarrhea, and nausea, cramps, vomiting, and itching of mouth.
Pistachios are an excellent source of potassium, but having too much potassium can be bad for the kidneys. People with kidney disease should avoid having too many pistachios. Pistachios can get contaminated with Aflatoxin, a carcinogen produced by fungus Aspergillus flavus. Consuming these pistachios on a long-term basis can increase the risk of hepatitis B and liver cancer.
Pistachios are little green nuts that have a delicious, slightly sweet flavor and are a great source of nutrition. The health benefits of pistachios include reduced risk of heart disease, lower risk of colon cancer, weight loss, and improved digestive health.