The largest drop in blood pressure, - 4.8 mm Hg, was associated with eating about one-and-a-half ounces of pistachios a day versus a -1.8 mm Hg on the low-fat diet and, -2.4 mm Hg, three ounces of pistachios per day. The diet containing three ounces of pistachios resulted in a significant decrease in peripheral vascular resistance, a measure of artery stiffness and heart rate versus the control diet. Fifty percent of the pistachios were given salted as a snack and the other half were unsalted and incorporated into recipes.   Interestingly, although high sodium intake is typically associated with high blood pressure, the largest drop in in blood pressure was not associated with the lowest sodium diet. Pistachios do provide potassium (8 percent Daily Value) and magnesium (8 percent Daily Value) which are important in maintaining a healthy blood pressure.

“In addition, these results are very exciting because they demonstrate further benefits of pistachios on another risk factor for cardiovascular disease,” added Penny M. Kris-Etherton, Ph.D., R.D., Distinguished Professor of Nutrition, and a lead researcher for the study. Dr. Kris-Etherton adds, “Our previous research suggests including pistachios in a healthy diet lowers LDL cholesterol in a dose-response fashion2 and increases antioxidants in the blood. (3)”

“This research adds to the growing body of literature on the health benefits of pistachios,” added Constance J. Geiger, Ph.D., R.D. who serves as a nutrition research consultant with the American Pistachio Growers. Dr. Geiger continues, “Nuts, such as pistachios, are an important part of a healthy diet.”

For more information and to read the full study, go to

About the Study

The research support was provided by the Western Pistachio Association, now known as the American Pistachio Growers, with partial support from the NIH-supported General Clinical Research Center at Pennsylvania State University. It was first reported on in 2007. It is relevant because lowering blood pressure may reduce the risk for stroke and heart disease.

Pistachios Pack Powerful Nutrition

In recent years the U.S. Food and Drug Administration (FDA) recognized that tree nuts, including pistachios, may help reduce the risk of heart disease when eaten as part of a diet low in saturated fat and cholesterol. Since then, the American Pistachio Growers have committed to learning more about the nutritional benefits of pistachios and the nuts’ impact on other health issues affecting Americans today.

Pistachio Facts

Pistachios are a naturally cholesterol-free and sodium-free snack that contains just 1.5 grams of saturated fat and 13 grams of fat per serving, the majority of which comes from monounsaturated and polyunsaturated fat. A one-ounce serving of pistachios equals 49 nuts, which is more nuts per serving than any other snack nut. One serving has as much potassium (290mg, 8 percent) as an orange (250 mg, 7 percent) and 3 g of fiber making it a nutritious snack choice or ingredient to incorporate into daily diets.

1 West SG, Gebaurer SK, Kay CD, Bagshaw DM, Savastano DM, Diefenbach C, Kris-Etherton P. Diets Containing Pistachios Reduce Systolic Blood Pressure and Peripheral Vascular Responses to Stress in Adults with Dyslipidemia. Hypertension. 2012 Jun 4. [Epub ahead of print] doi:10.1161/HYPERTENSIONAHA.111.182147

2 Gebauer SK, West SG, Kay CD, Alaupovic P, Bagshaw D, Kris-Etherton PM. “Effects of pistachios on cardiovascular disease risk factors and potential mechanisms of action: A dose-response study.” Amer J Clin Nutr. 2008;88:651–9.

3 Kay CD, Gebauer SK, West SG, Kris-Etherton PM. “Pistachios increase serum antioxidants and lower serum oxidized-LDL in hypercholesterolemic adults.” J Nutr. 2010;140:1093-98.