Numerous studies have looked at the effects of eating pistachios on various risk factors for heart health. These studies suggest that eating pistachios daily (one to three ounces or as 10%-20% of calories) may help to improve heart health in five ways:
1) Lowering total cholesterol, LDL cholesterol and non-HDL cholesterol;
2) Increasing antioxidants in the blood and decreasing oxidized-LDL;
3) Decreasing small dense LDL and increasing phytosterols levels in the blood;
4) Providing beneficial anti-inflammatory properties;
5) Reducing acute stress by lowering blood pressure, heart rate and peripheral vascular responses.
• A study published in the Journal of American College of Nutrition showed 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. Researchers looked at 52 overweight men and women who were asked to eat 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. Additionally, blood triglyceride levels were significantly lower in those eating pistachios.
[Li Z, et al. 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. 2010; 29(3):198-203.]
• In February 2013, the landmark PREDIMED study published in the New England Journal of Medicine showed a Mediterranean diet supplemented with nuts, such as pistachios, significantly reduced cardiac events. In this clinical trial of about 7,400 subjects, those who ate a Mediterranean diet with either one ounce of nuts per day or one liter of olive oil per week had a 30% risk reduction in heart disease-related events. Importantly, this risk reduction is the same as for statins, which are cholesterol-lowering drugs.
[Estruch R, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. New Engl J Med. 2013 Apr 4;368(14):1279-1290.]
• Published in 2010 in the Archives of Internal Medicine, a pooled analysis of 25 studies suggests that eating nuts, such as pistachios, has a total and LDL (bad) cholesterol-lowering effect, further confirming the evidence that regular nut consumption can lower the risk of coronary heart disease.
[Sabate J, et al. Nut consumption and blood lipids: A pooled analysis of 25 intervention trials. Arch Intern Med. 2010; 170(9):821-827.]
• Two PREDIMED study papers, published in 2013 in the Public Library of Science Online Journal and BioMed Central, presented cross-sectional data from the beginning of the trial. Both assessed 7,216 subjects and the associations between the frequency and amount of nuts participants ate. Those subjects who ate more than three servings of nuts, including pistachios, per week had a 39% lower mortality risk. Notably, the researchers also found similar reductions for cancer and cardiovascular mortality risk.
[Ibarrola-Jurado N, et al. Cross-sectional assessment of nut consumption and obesity, metabolic syndrome and other cardiometabolic risk factors: The PREDIMED study. PLoS One. February 2013; 8(2): e57367.]
[Guasch-Ferré M, et al. Frequency of nut consumption and mortality risk in the PREDIMED nutrition intervention trial. BMC Medicine 2013. Jul 16;11:164.]
Below you’ll find a handful of additional recent studies on pistachios and heart health.
Aldemir M, et al. Pistachio diet improves erectile function parameters and serum lipid profiles in patients with erectile dysfunction.
Internat J Impotence Res. 2011;23:32-38.
• Researchers investigated the effects of Antep pistachios on erectile function and serum lipid levels in patients with erectile dysfunction.
• A total of 17 married male patients between the ages of 38 and 59 years with erectile dysfunction participated in the study for at least 12 months. The participants ate 100 grams (about 3.5 ounces) of pistachios daily for 3 weeks.
• The results demonstrated that a pistachio diet improved erectile function parameters without any associated side effects. Furthermore, the lipid parameters showed statistically significant improvements after this diet, including a significant reduction in total blood cholesterol and LDL ('bad') cholesterol, and a significant increase in HDL ('good') cholesterol.
Baer DJ, et al. Measured energy value of pistachios in the human diet.
Br J Nutr. 2011;Jun 28:1-6.
• Researchers set out to measure energy value of pistachios when eaten.
• In the study, 16 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.
• 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.
• Given the results, the authors concluded that pistachios can be part of a heart-healthy diet.
Dreher ML. Pistachio nuts: composition and potential health benefits.
Nutr Rev. 2012;70(4):234-40.
• This review examines the nutrients and phytochemicals in pistachios as well as the potential health effects of pistachios.
• Five published randomized clinical studies have shown that pistachios have a beneficial effect on blood lipid profiles.
• Emerging clinical evidence suggests that pistachios may help reduce oxidative and inflammatory stress and promote vascular health, glycemic control, appetite management, and weight control.
Edwards K, et al. Effect of pistachio nuts on serum lipid levels in patients with moderate hypercholesterolemia.
J Am Coll Nutr. 1999; 18(3):229-32.
• The goal of the study was to determine whether substituting 20% of the daily caloric intake in the form of pistachios will improve the lipid profiles of humans with primary, moderate hypercholesterolemia.
• In the study, 4 men (ages 41-53) and 6 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.
• After three weeks, there was a decrease in total cholesterol, an increase in HDL, a decrease in the total cholesterol/HDL ratio and a decrease in the LDL/HDL ratio.
• The authors conclude that eating pistachios instead of other dietary fat calories may improve blood lipid levels, and potentially decrease heart disease risk.
Gebauer SK, et al. Effects of pistachios on cardiovascular risk factors and potential mechanisms of action: A dose-response study.
Am J Clin Nutr. 2008; 88:651-9.
• Researchers evaluated the effects of 2 doses of pistachios, added to a lower-fat diet, on lipids and lipoproteins, apolipoprotein (apo)-defined lipoprotein subclasses, and plasma fatty acids.
• The subjects - 10 men and 18 women with elevated LDL cholesterol - ate pistachios as either 10% (about one serving) or 20% (about two 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 of pistachios 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.
Holligan S, et al. A moderate-fat diet with pistachios lowers small-dense LDL and improves markers of insulin sensitivity in subjects with moderately-elevated cholesterol levels.
FASEB J. 2013:27; A5071, 1057.3.
• Researchers evaluated the dose-response effects of pistachios over 4 weeks, on markers of insulin sensitivity in 28 individuals with moderately elevated LDL-C.
• Three test diets (SFA ≈ 8%; cholesterol
• Results showed a significant effect of dietary modifications on small-dense LDL levels and TG/HDL-C ratio.
• Pistachio inclusion in a moderate-fat diet (≈ 35%) favorably affects insulin sensitivity and contributes to a beneficial cardio-metabolic profile.
Kay CD, et al. Pistachios increase serum antioxidants and lower serum oxidized-LDL in hypercholesterolemic adults.
J Nutr. 2010;Jun;140(6):1093-8.
• The goal of the study was to measure the effect of pistachios on oxidative status.
• 10 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.
Kocyigit A, et al. Effects of pistachio nuts consumption on plasma lipid profile and oxidative status in healthy volunteers.
Nutr Metab Cardiovasc Dis. 2006; 16:202-9.
• Effects of pistachio nuts consumption on plasma lipid profile and oxidative status were investigated in healthy volunteers with normal lipid levels.
• 20 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 for 3 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. 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.
Ryan E, et al. acid profile, tocopherol, squalene and phytosterol content of brazil, pecan, pine, pistachio and cashew nuts.
Int J Food Sci Nutr. 2006; May-Jun;57(3-4):219-28.
• This laboratory study determined the compounds in nuts that may contribute 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 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.
Sari I, et al. Effect of pistachio diet on lipid parameters, endothelial function, inflammation, and oxidative status: a prospective study.
• Researchers investigated the effect of the Antep pistachio (Pistacia vera L.) on blood glucose, lipid parameters, endothelial function, inflammation, and oxidation in healthy young men living in a controlled environment.
• Subjects were 32 normolipidemic, healthy young men between the ages of 21-24 years.
• A Mediterranean-type diet was substituted with unsalted pistachios (between 60-100 grams, or about 2-4 ounces ,daily) in place of other foods containing monounsaturated fats for four 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 the pistachio diet.
• The authors conclude that young men who eat pistachio nuts may see improvements in factors that promote heart health.
Sheridan MJ, et al. Pistachio nut consumption and serum lipid levels.
Am Coll Nutr. 2007; 26(2):141-8.
• Researchers studied the effects of eating 15% of the daily caloric intake in the form of pistachio nuts on the lipid profiles of free-living human subjects with primary, moderate hypercholesterolemia (serum cholesterol greater than 210 mg/dL).
• 15 overweight men and women, average age 60 years, with moderately high blood cholesterol levels ate about 15% of their daily calories from pistachio nuts (about 2-3 ounces) for 4 weeks.
• The pistachio diet 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.
West SG, et al. Diets containing pistachios reduce systolic blood pressure and peripheral vascular responses to stress in adults with dyslipidemia.
• Researchers evaluated effects of pistachios on flow-mediated dilation and blood pressure response to acute stress.
• 28 men and women with high blood cholesterol but who were otherwise healthy ate meals that included one, two or no servings of pistachios, while keeping total calories the same for four weeks.
• When participants were under stress as a result of a math test, those who had eaten the pistachios saw a reduction in systolic blood pressure (the top number), and heart rate.
• The authors conclude the positive effects of pistachios on blood vessels may be a reason why nut consumers tend to have better heart health.