This section briefly summarizes in less technical terms the results of scientific research related to pistachio nuts. Overall these studies demonstrate that pistachios can be part of a heart-healthy diet and pistachios promote heart-healthy blood lipid profiles. The studies are listed in chronological order.
Twenty-eight men and women with high blood cholesterol but otherwise healthy were provided meals that included either one, two or no servings of pistachios, while keeping total calories the same. Each diet was followed for four weeks. When participants were under stress as a result of a math test, those eating pistachios saw a reduction in systolic blood pressure (the top number), and heart rate. The positive effects of pistachios on blood vessels may be a reason why nut consumers tend to have better heart health.
West SG, Gebauer SK, Kay CD, Bagshaw DM, Savastano DM, Diefenbach C, Kris-Etherton PM. Diets containing pistachios reduce systolic blood pressure and peripheral vascular responses to stress in adults with dyslipidemia. Hypertension. 2012 Jul;60(1):58-63.
Sixteen men and women between the ages of 29 and 64 ate either 1.5 or 3 ounces of pistachios per day for 3 weeks as part of a controlled diet. Blood, urine and feces samples were collected. After eating either 1.5 or 3 ounces of pistachios, LDL ('bad') cholesterol levels were 6% lower. There was no change in total cholesterol, HDL ('good') cholesterol or triglyceride levels. The authors conclude that pistachios can be part of a heart-healthy diet.
Baer DJ, Gebauer SK, Novotny JA. 2011. Measured energy value of pistachios in the human diet. Br J Nutr. Jun 28:1-6.
After eating 100 grams (about 3.5 ounces) of pistachios daily for 3 weeks, 17 men between the ages of 38 and 59 years had a significant reduction in total blood cholesterol and LDL ('bad') cholesterol, and a significant increase in HDL ('good') cholesterol. The authors speculate that the healthy fats in pistachios, as well as the natural plant sterols, may have contributed to the improvement in blood lipids.
Aldemir M, Okulu E, Neşelioğlu S, Erel O, Kayıgil O. 2011. Pistachio diet improves erectile function parameters and serum lipid profiles in patients with erectile dysfunction. Int J Impot Res. 23(1):32-8.
Fifty-two overweight men and women ate a diet containing 500 fewer calories per day than needed, which included either 240 calories of salted pistachios or 220 calories of salted pretzels. After 12 weeks, both groups lost weight, but those eating pistachios tended to lose more weight. Blood triglyceride levels were significantly lower in those eating pistachios. There were no differences between the groups in total cholesterol, HDL or LDL cholesterol. The authors conclude that pistachios as a portion-controlled snack can be part of a successful weight-loss regimen and that eating pistachios instead of a snack such as pretzels may have benefits for blood triglyceride levels as well.
Li Z, Song R, Nguyen C, Zerlin A, Karp H, Naowamondhol K, Thames G, Gao K, Li L, Tseng CH, Henning SM, Heber D. 2010. Pistachio nuts reduce triglycerides and body weight by comparison to refined carbohydrate snack in obese subjects on a 12-week weight loss program. J Am Coll Nutr. 29(3):198-203.
Ten men and 18 women between the ages of 35 and 61 years with high cholesterol levels ate either a low-fat diet with no pistachios or 10% or 20% of their calories per day from pistachios for 4 weeks. This ranged from 32 to 63 grams (about 1 to 2 ounces) per day or 63 to 126 grams (about 2 to 4.5 ounces) per day. Those eating pistachios had lower LDL ('bad') cholesterol levels and higher blood levels of antioxidants. The authors suggest that pistachios can be an important part of a heart-healthy diet.
Kay CD, Gebauer SK, West SG, Kris-Etherton PM. 2010. Pistachios increase serum antioxidants and lower serum oxidized-LDL in hypercholesterolemic adults. J Nutr. Jun;140(6):1093-8.
Thirty-two healthy men ages 21-24 years ate a Mediterranean-type diet that substituted unsalted pistachios (between 60-100 grams, or about 2-4 ounces, daily) in place of other foods containing monounsaturated fats for 4 weeks. Those eating pistachios had significantly lower LDL ('bad') cholesterol, total cholesterol and triglycerides. They also saw improvement in several blood markers for inflammation and oxidation—both important factors for heart disease risk. Endothelial function, a measure of blood vessel ability to open and close, also improved with pistachio nuts. The authors conclude that even young men who eat pistachio nuts may see improvements in factors that promote heart health.
Sari I, Baltaci Y, Bagci C, Davutoglu V, Erel O, Celik H, Ozer O, Aksoy N, Aksoy M. 2010. Effect of pistachio diet on lipid parameters, endothelial function, inflammation, and oxidative status: A prospective study. Nutrition. Apr;26(4):399-404
Ten men and 18 women with elevated LDL cholesterol ate pistachios as either 10% (about 1 serving) or 20% (about 2 servings) of daily calorie needs. This ranged from 32 to 63 grams (about 1 to 2 ounces) per day or 63 to 126 grams (about 2 to 4.5 ounces) per day. Pistachios were often eaten as a snack in place of pretzels and potato chips, or in recipes. After four weeks, LDL ('bad') cholesterol levels were reduced with as little as one serving per day. The authors conclude that, as part of a heart-healthy diet, pistachios can help manage blood lipid levels, perhaps even more effectively than a low-fat diet.
Gebauer SK, West SG, Kay CD, Alaupovic P, Bagshaw D, Kris-Etherton PM. 2008. Effects of pistachios on cardiovascular risk factors and potential mechanisms of action: A dose-response study. Am J Clin Nutr. 88:651-9.
Fifteen overweight men and women, average age 60 years, with moderately high blood cholesterol levels ate about 15% of their daily calorie needs as pistachio nuts (about 2-3 ounces) for 4 weeks. Eating pistachios resulted in improvements in several measures of blood cholesterol levels, including an increase in HDL ('good') cholesterol. There were no differences seen for total cholesterol or triglycerides, and no changes in weight or blood pressure. The authors suggest that including 2-3 ounces of pistachios within calorie requirements over 4 weeks may support heart health in people with moderately high blood cholesterol levels.
Sheridan MJ, Cooper JN, Erario M, Cheifetz CE. 2007. Pistachio nut consumption and serum lipid levels. Am Coll Nutr. 26(2):141-8.
Twenty healthy women and 24 healthy men (average age 33 years) ate either a regular diet with no pistachios or a diet that substituted pistachios for 20% of their daily calorie intake. After three weeks, those on the pistachio diet had a significant decrease in total cholesterol levels, an increase in HDL ('good') cholesterol and an increase in blood antioxidants. Blood triglyceride and LDL ('bad') cholesterol levels decreased, but this change was not significant. There was no change in body weight. The authors conclude that including pistachios as part of a calorie appropriate diet can improve blood lipid levels without weight gain.
Kocyigit A, Koylu AA, Keles H. 2006. Effects of pistachio nuts consumption on plasma lipid profile and oxidative status in healthy volunteers. Nutrition, Metabolism & Cardiovascular Diseases. 16:202-9.
Nuts, including pistachios, are known to support heart health. This laboratory study determined the compounds in nuts that might be contributing to heart health. Pistachio nuts had a higher percentage of monounsaturated fats than cashews, pecans, pine and Brazil nuts. Pistachios also contained the highest amount of gamma-tocopherol (a type of vitamin E), as well as the highest amount of beta-sitersterol, a plant sterol, compared to those other nuts. The researchers conclude that nuts contain many beneficial attributes and could be used in heart-healthy diets in place of other high-calorie snacks.
Ryan E, Galvin K, O'Connor TP, Maguire AR, O'Brien NM. 2006. Fatty acid profile, tocopherol, squalene and phytosterol content of brazil, pecan, pine, pistachio and cashew nuts. Int J Food Sci Nutr. May-Jun;57(3-4):219-28.
Four men (ages 41-53) and six women (ages 28-64) with a blood cholesterol level over 210 mg/dl ate 20% of their daily calorie intake per day as pistachio nuts for 3 weeks. There was a significant decrease in total cholesterol and an increase in HDL ('good') cholesterol. Triglycerides and LDL ('bad') cholesterol decreased but not significantly. Body weight and blood pressure did not change. The authors conclude that eating pistachios instead of other dietary fat calories may improve blood lipid levels, and potentially decrease heart disease risk.
Edwards K, Kwaw I, Matud J, Kurtz I. 1999. Effect of pistachio nuts on serum lipid levels in patients with moderate hypercholesterolemia. J Am Coll Nutr. 18(3):229-32.
To learn more about the health benefits of nuts in general, visit nuthealth.org.