Pistachios are heart-healthy tree nuts that have been around for centuries, but research is just unearthing the many health benefits of this tasty snack. Packed with protein, vitamins, and minerals, a one-ounce serving, about 49 pistachios, has only 150 calories.

“Most of the pistachios in the U.S. are grown in the naturally rich soils of California’s San Joaquin Valley, where the warm days and cool nights create the perfect setting to grow heart-healthy pistachios,” says registered dietitian Maggie Moon.

According to Good Housekeeping, pistachios are packed with nutritional benefits:

1. Plant-based complete protein. Moon says that pistachios are a great plant-protein choice compared to meat because they are naturally cholesterol-free and add fiber to your diet. They contain all nine essential amino acids.
2. May improve blood sugar levels. “Pistachios can be included as part of a healthy diet for eating right with diabetes,” says Moon. One study found that eating pistachios may lower glucose and insulin in prediabetic individuals.
3. May help you lose weight. The fiber and protein in pistachio nuts make you feel fuller, longer, according to WebMD. This can help you eat less overall and lose weight. Buying pistachios in their shells slows down your eating, making snacking more mindful. One study found that regular consumption of pistachios was associated with "significant reductions in BMI and waist circumference in overweight and obese men and women.”
4. Antioxidant and anti-inflammatory traits which help ward off illness. Moon says that their unique makeup of powerful antioxidant compounds includes tocopherols, carotenoids, chlorophyll and flavonoids.
5. A heart-healthy snack. Since 90% of the fats found in pistachio nuts are unsaturated, Moon says they are an excellent choice for snacking. “Scientific evidence suggests, but does not prove, eating 1.5 ounces per day of most nuts, such as pistachios, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease,” she tells Good Housekeeping.