Gebauer S.K., S.G. West, C.D. Kay, P. Alaupovic, D. Bagshaw, P.M. Kris-Etherton, 2008. Effects of pistachios on cardiovascular risk factors and potential mechanisms of action: A dose-response study. Am J Clin Nutr. 88:651-9.
Background: Nut consumption lowers cardiovascular disease (CVD) risk. Studies are lacking about the effects of pistachios, a nutrient-dense nut, on CVD risk factors, dose-response relations, and lipid-lowering mechanisms. Objective: We 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. To investigate the mechanisms of action, we measured cholesteryl ester transfer protein and indexes of plasma stearoyl-CoA desaturase activity (SCD). Design: In a randomized crossover controlled-feeding study, 28 individuals with LDL cholesterol ≥ 2.86 mmol/L consumed 3 isoenergetic diets for 4 wk each. Baseline measures were assessed after 2 wk of a typical Western diet. The experimental diets included a lower-fat control diet with no pistachios [25% total fat; 8% saturated fatty acids (SFAs), 9% monounsaturated fatty acids (MUFAs), and 5% polyunsaturated fatty acids (PUFAs)], 1 serving/d of a pistachio diet (1 PD; 10% of energy from pistachios; 30% total fat; 8% SFAs, 12% MUFAs, and 6% PUFAs), and 2 servings/d of a pistachio diet (2 PD; 20% of energy from pistachios; 34% total fat; 8% SFAs, 15% MUFAs, and 8% PUFAs). Results: The 2 PD decreased (P < 0.05 compared with the control diet) total cholesterol (-8%), LDL cholesterol (-11.6%), non-HDL cholesterol (-11%), apo B (-4%), apo B/apo A-I (-4%), and plasma SCD activity (-1%). The 1 PD and 2 PD, respectively, elicited a dose-dependent lowering (P < 0.05) of total cholesterol/HDL cholesterol (-1% and -8%), LDL cholesterol/HDL cholesterol (-3% and -11%), and non-HDL cholesterol/HDL cholesterol (-2% and -10%). Conclusions: Inclusion of pistachios in a healthy diet beneficially affects CVD risk factors in a dose-dependent manner, which may reflect effects on SCD.
O’Keefe, J.H., N.M. Gheewala, J.O. O’Keefe, 2008. Dietary Strategies for Improving Post-Prandial Glucose, Lipids, Inflammation, and Cardiovascular Health. J Am Coll Cardiol. 51:249-55
The highly processed, calorie-dense, nutrient-depleted diet favored in the current American culture frequently leads to exaggerated supraphysiological post-prandial spikes in blood glucose and lipids. This state, called postprandial dysmetabolism, induces immediate oxidant stress, which increases in direct proportion to the increases in glucose and triglycerides after a meal. The transient increase in free radicals acutely triggers atherogenic changes including inflammation, endothelial dysfunction, hypercoagulability, and sympathetic hyperactivity. Post-prandial dysmetabolism is an independent predictor of future cardiovascular events even in nondiabetic individuals. Improvements in diet exert profound and immediate favorable changes in the post-prandial dysmetabolism. Specifically, a diet high in minimally processed, high-fiber, plant-based foods such as vegetables and fruits, whole grains, legumes, and nuts will markedly blunt the post-meal increase in glucose, triglycerides, and inflammation. Additionally, lean protein, vinegar, fish oil, tea, cinnamon, calorie restriction, weight loss, exercise, and low-dose to moderate-dose alcohol each positively impact post-prandial dysmetabolism. Experimental and epidemiological studies indicate that eating patterns, such as the traditional Mediterranean or Okinawan diets, that incorporate these types of foods and beverages reduce inflammation and cardiovascular risk. This anti-inflammatory diet should be considered for the primary and secondary prevention of coronary artery disease and diabetes.
Kris-Etherton, P.M., F.B. Hu, E. Ros, J. Sabaté, 2008. The role of tree nuts and peanuts in the prevention of coronary heart disease: multiple potential mechanisms. J Nutr. 138, 1746S-1751.
Epidemiologic and clinical trial evidence has demonstrated consistent benefits of nut and peanut consumption on coronary heart disease (CHD) risk and associated risk factors. The epidemiologic studies have reported various endpoints, including fatal CHD, total CHD death, total CHD, and nonfatal myocardial infarct. A pooled analysis of 4 U.S. epidemiologic studies showed that subjects in the highest intake group for nut consumption had a 35% reduced risk of CHD incidence. The reduction in total CHD death was due primarily to a decrease in sudden cardiac death. Clinical studies have evaluated the effects of many different nuts and peanuts on lipids, lipoproteins, and various CHD risk factors, including oxidation, inflammation, and vascular reactivity. Evidence from these studies consistently shows a beneficial effect on these CHD risk factors. The LDL cholesterol-lowering response of nut and peanut studies is greater than expected on the basis of blood cholesterol-lowering equations that are derived from changes in the fatty acid profile of the diet. Thus, in addition to a favorable fatty acid profile, nuts and peanuts contain other bioactive compounds that explain their multiple cardiovascular benefits. Other macronutrients include plant protein and fiber; micronutrients including potassium, calcium, magnesium, and tocopherols; and phytochemicals such as phytosterols, phenolic compounds, resveratrol, and arginine. Nuts and peanuts are food sources that are a composite of numerous cardioprotective nutrients and if routinely incorporated in a healthy diet, population risk of CHD would therefore be expected to decrease markedly.
Natoli, S., P. McCoy, 2007. A review of the evidence: nuts and body weight. Asia Pac J Clin Nutr. 16 (4):588-597 588.
There is currently no single dietary or lifestyle intervention that is effective in long-term weight loss. Traditional weight loss diets tend to be low in total fat and therefore often restrict nut consumption. However, nuts are an important source of many vitamins, minerals, monounsaturated and polyunsaturated fatty acids. This paper reviewed all the available evidence from the literature in relation to nut consumption and body weight. The findings show that the role of nut consumption in body weight management is varied. Nuts, when included as part of an energy-controlled diet, were found in some instances to assist with weight loss. However, when nuts were added to an existing diet without controlling for energy intake, body weight increased, although to a lesser extent than theoretically predicted. There is limited evidence on the effect nut consumption has on type 2 diabetes, although available evidence indicates that nuts as part of a healthy diet do not cause weight gain and can have a positive influence on the fatty acid profile of a person with diabetes. This review shows there is a lack of evidence to support the restriction of nut consumption in weight management, indicating that further research is needed to assess the role of nuts in weight management.
Fleischer, D.M., 2007. The natural history of peanut and tree nut allergy. Current Allergy and Asthma Reports. 7:175–181.
Peanut and tree nut allergies were once thought to be permanent. Recent studies have shown that about 20% and 10%, respectively, of young patients may outgrow peanut and tree nut allergies. For the majority of patients, however, the natural history is not favorable. In addition, approximately 8% of patients who outgrow peanut allergy may suffer a recurrence. The rising prevalence of these allergies, coupled with the knowledge that allergic reactions to these foods have the potential to be severe or fatal and that accidental exposures are common, makes developing effective treatments to alter the natural history of peanut and tree nut allergies even more crucial for those who will not outgrow them. At this time, avoidance of the offending foods and being prepared to treat a potential reaction after accidental ingestion is the only treatment, but many promising therapeutic interventions are being investigated.
Ritter, M.M.C., G.P. Savage, 2007. Soluble and insoluble oxalate content of nuts. Journal of Food Composition and Analysis. 20:169-174.
This study was conducted to determine the oxalate contents in common nuts either locally grown or imported into New Zealand. Samples of imported nuts were purchased from supermarkets in Christchurch while locally grown nuts were obtained directly from the growers. In this experiment gastric soluble and intestinal soluble oxalates were extracted from the nuts using an in vitro assay, which involved incubations of the food samples for 2 h at 37 1C in gastric and intestinal juice. The extracted oxalates were then determined by HPLC chromatography. Roasted pistachio nuts and chestnuts contained very low levels (<85 mg/100 g fresh weight (FW)) of gastric soluble oxalate. Peanuts, Spanish peanuts, peanut butter, ginkgo, cashew nuts and pecan nuts all contained relatively low levels of gastric soluble oxalate (147–250 mg gastric soluble oxalate/100 g FW). Almonds, Brazil, pine and candle nuts contained high levels of gastric soluble oxalate (492.0–556.8 mg/100 g FW). The intestinal soluble oxalate is the fraction that will be absorbed in the small intestine. Peanuts, Spanish peanuts, peanut butter, ginkgo and pecan nuts all contained relatively low levels of intestinal soluble oxalate (129–173 mg intestinal soluble oxalate/100 g FW). Almonds, Brazil, cashew and candle nuts contained higher levels of intestinal soluble oxalate (216–305 mg/100 g FW). Pine nuts contained the highest levels of intestinal soluble oxalate (581 mg/100 g FW), while chestnuts and roasted pistachio nuts were low (72 and 77 mg /100 g FW). Overall the mean soluble oxalate content of nuts was 78% of the gastric soluble oxalate content (41–100%). The results obtained in this study confirm that the intestinal soluble oxalate contents of nuts range widely and people who have a tendency to form kidney stones would be wise to moderate their consumption of certain nuts.
Sheridan, M.J., J.N. Cooper, M. Erario, C.E. Cheifetz, 2007. Pistachio nut consumption and serum lipid levels. Am Coll Nutr. 26(2):141-8.
Objective: Clinical and epidemiological studies have reported the beneficial effects of tree nuts and peanuts on serum lipid levels. We studied the effects of consuming 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). Methods: Design: Randomized crossover trial. Setting: Outpatient dietary counseling and blood analysis. Subjects: 15 subjects with moderate hypercholesterolemia. Intervention: Fours weeks of dietary modification with 15% caloric intake from pistachio nuts. Measures of Outcome: Endpoints were serum lipid levels of total cholesterol, HDL-C, LDL-C, VLDL-C, triglycerides and apolipoproteins A-1 and B-100. BMI, blood pressure, and nutrient intake (total energy, fat, protein, and fiber) were also measured at baseline, during, and after dietary intervention. Results: No statistically significant differences were observed for total energy or percent of energy from protein, carbohydrate or fat. On the pistachio nut diet, a statistically significant decrease was seen for percent energy from saturated fat (mean difference, -2.7%; 95% CI, -5.4% to -0.08%; p = 0.04). On the pistachio nut diet, statistically significant increases were seen for percent energy from polyunsaturated fat (mean difference, 6.5%; 95% CI, 4.2% to 8.9%; p<.0001) and fiber intake (mean difference, 15 g; 95% CI, 8.4 g to 22 g; p = 0.0003). On the pistachio diet, statistically significant reductions were seen in TC/HDL-C (mean difference, -0.38; 95% CI, -0.57 to -0.19; p = 0.001), LDL-C/HDL-C (mean difference, -0.40; 95% CI, -0.66 to -0.15; p = 0.004), B-100/A-1 (mean difference, -0.11; 95% CI, -0.19 to -0.03; p = 0.009) and a statistically significant increase was seen in HDL-C (mean difference, 2.3; 95% CI, 0.48 to 4.0; p = 0.02). No statistically significant differences were seen for total cholesterol, triglycerides, LDL-C, VLDL-C, apolipoprotein A-1 or apolipoprotein B-100. No changes were observed in BMI or blood pressure. Conclusion: A diet consisting of 15% of calories as pistachio nuts (about 2–3 ounces per day) over a four week period can favorably improve some lipid profiles in subjects with moderate hypercholesterolemia and may reduce risk of coronary disease.
Ryan, E., K. Galvin, T.P. O’Connor, A.R. Maguire, N.M. O’Brien, 2006. Fatty acid profile, tocopherol, squalene and phytosterol content of brazil, pecan, pine, pistachio and cashew nuts. International Journal of Food Sciences and Nutrition. 57(3/4):219-228.
Nuts contain bioactive constituents that elicit cardio-protective effects including phytosterols, tocopherols and squalene. The objective of the present study was to determine the total oil content, peroxide value, fatty acid composition and levels of tocopherols, squalene and phytosterols in oil extracted from freshly ground brazil, pecan, pine, pistachio and cashew nuts. The total oil content of the nuts ranged from 40.4 to 60.8% (w/w) while the peroxide values ranged from 0.14 to 0.22 mEq O2/kg oil. The most abundant monounsaturated fatty acid was oleic acid (C18:1), while linoleic acid (C18:2) was the most prevalent polyunsaturated fatty acid. The levels of total tocopherols ranged from 60.8 to 291.0 mg/g. Squalene ranged from 39.5 mg/g oil in the pine nut to 1377.8 mg/g oil in the brazil nut. β-Sitosterol was the most prevalent phytosterol, ranging in concentration from 1325.4 to 4685.9 mg/g oil. In conclusion, the present data indicate that nuts are a good dietary source of unsaturated fatty acids, tocopherols, squalene and phytosterols.
Seeram, N.P., Y. Zhang, S.M. Henning, R. Lee, Y. Niu, G. Lin, D. Heber, 2006. Pistachio skin phenolics are destroyed by bleaching resulting in reduced antioxidative capacities. J. Agric. Food Chem. 54:7036-7040.
Pistachio shells split naturally prior to maturity leading to their unique crack-shell form. Within 24 h of harvest, hull-trapped moisture may cause shell staining. The illegal process of bleaching has been used to restore a desirable white color to pistachio shells. It is not known whether bleaching adversely affects phytochemical levels in pistachios. Therefore, we identified for the first time multiple pistachio skin phenolics as quercetin (14.9 µg/g), luteolin (10.0 µg/g), eriodictyol (10.2 µg/g), rutin (1.6 µg/g), naringenin (1.2 µg/g), apigenin (0.2 µg/g), and the anthocyanins, cyanidin-3-galactoside (696 µg/g) and cyanidin-3-glucoside (209 µg/g). We investigated the effects of bleaching (0.1-50% hydrogen peroxide) on phenolic levels and antioxidative capacities in raw and roasted nuts. Because of their flavylium cation structures, anthocyanins were the most sensitive to bleaching. Bleaching decreased total anthocyanin levels [íg/g of skins (% hydrogen peroxide)]: 905 and 549 (0%); 653 and 145 (0.1%); 111 and 18.4 (5%); 6.1 and 3.2 (25%); 0 and 0 (50%) for raw and roasted nuts, respectively. Bleaching also reduced antioxidative capacity [µM/g of Trolox (% hydrogen peroxide)]: 945 and 725 (0%); 940 and 472 (0.1%); 930 and 455 (5%); 433 and 370 (25%); 189 and 173 (50%), for raw and roasted nuts, respectively. Raw nuts preserved phenolic levels and antioxidant capacity better than roasted nuts, suggesting contributing effects of other substances and/or matrix effects that are destroyed by the roasting process. The destruction of bioactive phenolics in pistachio skins may negatively impact the potential health benefits arising from pistachio consumption.
Wu, X., Beecher, G.R., Holden, J.M., Haytowitz, D.B., Gebhardt, S.E., R.L. Prior, 2006. Concentrations of anthocyanins in common foods in the United States and estimation of normal consumption. J. Agric. Food Chem. 54:4069-75.
Anthocyanins (ACNs) are water-soluble plant pigments that have important functions in plant physiology as well as possible health effects. Over 100 common foods were screened for ACNs, and 24 of them were found to contain ACNs. Concentrations of total ACNs varied considerably from 0.7 to 1480 mg/100 g of fresh weight in gooseberry (‘Careless’ variety) and chokeberry, respectively. Not only does the concentration vary, but the specific anthocyanins present in foods are also quite different. Only six common aglycones, delphinidin, cyanidin, petunidin, pelargonidin, peonidin, and malvidin, were found in all of these foods. However, their sugar moieties and acylation patterns varied from food to food. Results from this study will add to the available data for the USDA Nutrient Database of flavonoids. On the basis of the concentration data and updated food intake data from NHANES 2001-2002, the daily intake of ACNs is estimated to be 12.5 mg/day/person in the United States. Of the different aglycones, cyanidin, delphinidin, and malvidin were estimated to contribute 45, 21, and 15%, respectively, of the total ACN intake. Nonacylated contributed 77% compared to 23% from acylated ACNs.
