Abstracted by Greg Arnold, DC, CSCS. Participants consuming pistachios had a 6.4% decrease in the total cholesterol, HDL cholesterol ratio, 43% increase in blood vessel relaxation, 4.5 % decrease in Body Mass Index, and 24% improvement in a marker for inflammation.
Nuts like pistachios consumed in moderation help reduce intake of saturated fat and increase intake of both monounsaturated fats and polyunsaturated fatty acids](PUFA) (1,2 3). One ounce of pistachios provides 160 calories, 12.7 grams of fat (6.7 grams monounsaturated, 3.8 grams polyunsaturated fat, 1.5 grams saturated fat), 5.9 grams protein, and 2.8 grams of fiber. They also provide 470 milligrams of antioxidants called polyphenols, which play a role in the “prevention of degenerative diseases, particularly cardiovascular diseases and cancers” (4).
Now a new review of research on pistachios (5) finds three specific ways pistachios improve health.
Improving Cholesterol Profiles
In a 2007 study (6), 2-3 ounces of pistachios per day in 15 subjects (comprising 15% of their daily calorie intake) for 4 weeks showed a 10% decrease in LDL cholesterol (164 to 148 mg/dL), compared to no change in the placebo group. The pistachio group also had a 6.4% decrease in the Total Cholesterol/HDL cholesterol ratio (4.7 to 4.4) to compared to a slight increase (4.7 to 4.8) in the placebo group. These results led the researchers to conclude that “the addition of pistachio nuts at 15% of daily fat calories (2–3 ounces per day)…can favorably modify lipoprotein levels in subjects with [elevated cholesterol levels].”
Inflammation and Blood Vessel Health
In a 2010 study (7), one group of participants replaced 20% of its daily intake with pistachios, while another group ate a standard Mediterranean Diet for 4 weeks. The pistachio substitution produced 19% lower saturated fat intake (4.9 vs. 5.8% total calories), 52% higher monounsaturated fat intake (20.2 vs. 13.3% total calories), and 50% less polyunsaturated fat intake (7.1 vs. 14.2% total calories) with nearly identical calorie intake (1983 vs. 1966 calories/day).
The pistachio group had “significantly enhanced” blood vessel relaxation (called “endothelium-dependent vasodilation”), with a 43% increase in the pistachio group (7.19 to 10.29%) compared to an 8.6% increase (7.19 to 7.86%) in the Mediterranean Diet group. This significant increase was also seen in levels of an enzyme called superoxide dismutase (43.5% increase in the pistachio group (1.08 to 1.55 Units/milliliter) compared to 61% decrease in the Mediterranean Diet group (1.08 to 0.42 U/mL)) as well as a 45% decrease in levels of an inflammatory enzyme called interleukin-6 (1.44 to 0.79 picograms/milliliter) compared to a 21% decrease (1.44 to 1.14 pg/mL) in the Mediterranean Diet group.
In a 2010 study (8), two groups consumed 500 less calories per day than their resting metabolic rate. One group (31 subjects) consumed 1.5 ounces of pistachios (240 calories) while the other group consumed 220 calories of salted pretzels (28 subjects) for 12 weeks. While both groups lost similar amounts of weight, those in the pistachio group had a 4.5% decrease in Body Mass Index (30.1 to 28.8 kg/m2) compared to a 2% decrease in the pretzel group (30.9 to 30.3 kg/m2). The researchers pointed to the ability of pistachios to improve feelings of fullness (“satiety”) and concluded that “pistachios can be consumed as a portion-controlled snack for individuals restricting calories to lose weight without concern that pistachios will cause weight gain.”
Abstracted from “Pistachio nuts: composition and potential health benefits” in the April 2012 issue of Nutrition Reviews. Posted April 20, 2012. r/km
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- US Department of Agriculture and US Department of Health and Human Services. Dietary Guidelines for Americans, 2010: 7th ed. Washington, DC: US Dept of Agriculture and US Dept of Health and Human Services; 2010.
- Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010. Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010. Part D. Section 3: Fatty Acids and Cholesterol.Washington, DC: US Dept of Agriculture and Dept of Health and Human Services; 2010: D3-41–D3-44.
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