Archive

Research Area: Cardiovascular Health

Diets containing pistachios reduce systolic blood pressure and peripheral vascular responses to stress in adults with dyslipidemia.

West, S.G., S.K. Gebauer, C.D. Kay, D.M. Bagshaw, D.M. Savastano, C. Diefenbach, P.M. Kris-Etherton, 2012. Diets containing pistachios reduce systolic blood pressure and peripheral vascular responses to stress in adults with dyslipidemia. Hypertension. 60:58-63.

Nut consumption reduces cardiovascular risk, and reductions in blood pressure and peripheral vascular resistance may be important mediators of this relationship. We evaluated effects of pistachios on flow-mediated dilation and blood pressure response to acute stress. Twenty-eight adults with dyslipidemia completed a randomized, crossover, controlled-feeding study. All of the meals were provided and calories were controlled. After 2 weeks on a typical Western diet (35% total fat and 11% saturated fat), test diets were presented in counterbalanced order for 4 weeks each, a low-fat control diet (25% total fat and 8% saturated fat), a diet containing 10% of energy from pistachios (on average, 1 serving per day; 30% total fat and 8% saturated fat), and a diet containing 20% of energy from pistachios (on average, 2 servings per day, 34% total fat and 8% saturated fat). None of the resting hemodynamic measures significantly differed from pretreatment values. When resting and stress levels were included in the repeated-measures analysis, average reductions in systolic blood pressure were greater after the diet containing 1 serving per day versus 2 servings per day of pistachios (mean change in systolic blood pressure, -4.8 vs -2.4 mm Hg, respectively; P<0.05). After the higher dose, there were significant reductions in peripheral resistance (-62.1 dyne·sXcm-5) and heart rate (-3 bpm) versus the control diet (P<0.0001). These changes were partially offset by increases in cardiac output. There was no effect of diet on fasting flow-mediated dilation. Reductions in peripheral vascular constriction and the resulting decrease in hemodynamic load may be important contributors to lower risk in nut consumers.

Pistachio nuts: composition and potential health benefits.

Dreher, M.L., 2012. Pistachio nuts: composition and potential health benefits. Nutrition Reviews. Vol.70(4):234–240.

The pistachio is a nutrient-dense nut with a heart-healthy fatty-acid profile as well as protein, dietary fiber, potassium, magnesium, vitamin K, γ-tocopherol, and a number of phytochemicals. The pistachio’s unique green and purple kernel color is a result of its lutein and anthocyanin content. Among nuts, pistachios contain the highest levels of potassium, γ-tocopherol, vitamin K, phytosterols, and xanthophyll carotenoids. Five published randomized cardiovascular trials have shown that pistachios promote heart-healthy blood lipid profiles. Exploratory clinical studies suggest that pistachios help maintain healthy antioxidant and anti-inflammatory activity, glycemic control, and endothelial function. When consumed in moderation, pistachios may help control body weight because of their satiety and satiation effects and their reduced net metabolizable energy content. One study with subjects in a weight-loss program demonstrated lower body mass index and triglyceride levels in individuals who consumed pistachios compared with those who consumed an isocaloric pretzel snack. Emerging research suggests that the addition of pistachios to high-glycemic meals may lower the overall postprandial glycemic response. This review examines the nutrients and phytochemicals in pistachios as well as the potential health effects of these nuts.

Effects of pistachios on body weight in Chinese subjects with metabolic syndrome.

Wang, X., Z. Li, Y. Liu, X. Lv, W. Yang, 2012. Effects of pistachios on body weight in Chinese subjects with metabolic syndrome. Nutrition Journal. 11:20.

Background: Studies have shown that pistachios can improve blood lipid profiles in subjects with moderate hypercholesterolemia which could reduce the risk of cardiovascular disease. However, there is also a widely perceived view that eating nuts can lead to body weight gain due to their high fat content. Purpose: To investigate the impact of different dosages of pistachios on body weight, blood pressure, blood lipids, blood glucose and insulin in subjects with metabolic syndrome. Methods: Ninety subjects with metabolic syndrome (consistent with 2005 International Diabetes Federation metabolic syndrome standard without diabetes) were enrolled in three endocrinology outpatient clinics in Beijing. All subjects received dietary counseling according to the guidelines of the American Heart Association Step I diet. After a 4 week run-in, subjects were randomized to consume either the recommended daily serving of 42 g pistachios (RSG), a higher daily serving of 70 g pistachio (HSG) or no pistachios (DCG) for 12 weeks. Results: Subjects in all three groups were matched at baseline for BMI: DCG 28.03 ± 4.3; RSG 28.12 ± 3.22; and HSG 28.01 ± 4.51 kg/m2. There were no significant changes in body weight or BMI in any groups during the study nor any change from baseline at any time point in any group. During the entire study, there were no significant differences in waist-to-hip ratio among the groups or any change from baseline in any group (DCG -0.00 ± 0.03, RSG -0.01 ± 0.02 and HSG 0.01 ± 0.04). There were no significant differences detected among groups in triglycerides, fasting glucose and 2 hour postprandial glucose following a 75 gram glucose challenge. Exploratory analyses demonstrated that glucose values 2 h after a 75 gm glucose challenge were significantly lower at week 12 compared with baseline values in the HSG group (-1.13 ± 2.58 mmol/L, p = 0.02), and a similar trend was noted in the RSG group (-0.77 ± 2.07 mmol/L, p = 0.06), while no significant change was seen in the DCG group (-0.15 ± 2.27 mmol/L, p = 0.530). At the end of study, serum triglyceride levels were significantly lower compared with baseline in the RSG group (-0.38 ± 0.79 mmol/L, p = 0.018), but no significant changes were observed in the HSG or DCG groups. Conclusion: Despite concerns that pistachio nut consumption may promote weight gain, the daily ingestion of either 42 g or 70 g of pistachios for 12 weeks did not lead to weight gain or an increase in waist-to-hip ratio in Chinese subjects with metabolic syndrome. In addition, pistachio consumption may improve the risk factor associated with the metabolic syndrome.

Out-of-hand nut consumption is associated with improved nutrient intake and health risk markers in US children and adults: National Health and Nutrition Examination Survey 1999-2004.

O’Neil, C.E., D.R. Keast, T.A. Nicklas, V.L. Fulgoni, 2012. Out-of-hand nut consumption is associated with improved nutrient intake and health risk markers in US children and adults: National Health and Nutrition Examination Survey 1999-2004. Nutrition Research. 32:185-194.

The purpose of this study was to determine the association of out-of-hand nut (OOHN) consumption with nutrient intake, diet quality, and the prevalence of risk factors for cardiovascular disease and metabolic syndrome. Data from 24-hour recalls from individuals aged 2+ years (n = 24,385) participating in the 1999-2004 National Health and Nutrition Examination Survey were used. The population was divided into children aged 2 to 11, 12 to 18, and adults 19+ years, and each group was dichotomized into OOHN consumers and nonconsumers. Out-of-hand nut consumers were defined as those individuals consuming ¼ oz of nuts or more per d. Means, standard errors, and covariate-adjusted analyses of variance were determined using appropriate sample weights. Diet quality was determined using the Healthy Eating Index-2005. Significance was set at P < .05. The percent of OOHN consumers increased with age: 2.1% ± 0.3%, 2.6% ± 0.3%, 6.5% ± 0.5%, and 9.6% ± 0.5% those aged 2 to 11, 12 to 18, 19 to 50, and 51+ years, respectively. The 2 latter groups were combined into a single group of consumers aged 19+ years for subsequent analyses. Consumers of OOHN from all age groups had higher intakes of energy, monounsaturated and polyunsaturated fatty acids, dietary fiber, copper, and magnesium and lower intakes of carbohydrates, cholesterol, and sodium than did nonconsumers. Diet quality was higher in OOHN consumers of all age groups. In children aged 2 to 11 years, consumers had a higher prevalence of overweight/obesity. In those aged 12 to 18 years, weight and percent overweight were lower in consumers. Adult consumers had higher high-density lipoprotein cholesterol, red blood cell folate, and serum folate levels and lower insulin, glycohemoglobin, and C-reactive protein levels than did nonconsumers. Adult consumers also had a 19% decreased risk of hypertension and a 21% decreased risk of low high-density lipoprotein cholesterol levels. Data suggested that OOHN consumption was associated with improved nutrient intake, diet quality, and, in adults, a lower prevalence of 2 risk factors for metabolic syndrome. Consumption of OOHN, as part of a healthy diet, should be encouraged by health professionals.

Nut consumption is associated with decreased health risk factors for cardiovascular disease and metabolic syndrome in U.S. adults: NHANES 1999–2004.

O’Neil, C.E., D.R. Keast, T.A. Nicklas, V.L. Fulgoni, 2011. Nut consumption is associated with decreased health risk factors for cardiovascular disease and metabolic syndrome in U.S. adults: NHANES 1999–2004. Journal of the American College of Nutrition. 30(6):502–510.

Background: Few recent epidemiologic studies have assessed the effect that nut consumption (including tree nuts and peanuts) has on health risks, including metabolic syndrome (MetS). Objective: This study compared the health risk for cardiovascular disease, type 2 diabetes, and MetS of nut consumers with that of nonconsumers. Design: Adults 19+ years (n = 13,292) participating in the 1999–2004 National Health and Nutrition Examination Survey were used. Intake from 24-hour recalls was used to determine intake. Nut/tree nut consumers consumed ≥¼ ounce per day. Covariate-adjusted means, standard errors, and prevalence rates were determined for the nut consumption groups. Results: The prevalence of nut consumers was 18.6% ± 0.7% and 21.0% ± 0.9% in those 19–50 years and 51 years and older, respectively. Nut consumption was associated with a decreased body mass index (27.7 kg/m2 ± 0.2 vs 28.1 ± 0.1 kg/m2, p<0.05), waist circumference (95.6 ± 0.4 cm vs 96.4 ± 0.3 cm, p < 0.05), and systolic blood pressure (121.9 ± 0.4 mmHg vs 123.20 ± 0.3 mmHg, p < 0.01) compared with nonconsumers. Tree nut consumers also had a lower weight (78.8 ± 0.7 kg vs 80.7 ± 0.3 kg, p < 0.05). Nut consumers had a lower percentage of two risk factors for MetS: hypertension (31.5% ± 1.0% vs 34.2% ± 0.8%, p < 0.05) and low high density lipoprotein-cholesterol (HDL-C) (29.6% ± 1.0% vs 34.8% ± 0.8%, p < 0.01). Tree nut consumers had a lower prevalence of four risk factors for MetS: abdominal obesity (43.6% ± 1.6% vs 49.5% ± 0.8%, p < 0.05), hypertension (31.4% ± 1.2% vs 33.9% ± 0.8%, p < 0.05), low HDL-C (27.9% ± 1.7% vs 34.5% ± 0.8%, p < 0.01), high fasting glucose (11.4% ± 1.4% vs 15.0% ± 0.7%, p < 0.05), and a lower prevalence of MetS (21.2% ± 2.1% vs 26.6% ± 0.7%, p < 0.05). Conclusion: Nut/tree nut consumption was associated with a decreased prevalence of selected risk factors for cardiovascular disease, type 2 diabetes, and MetS.

Total polyphenol excretion and blood pressure in subjects at high cardiovascular risk.

Medina-Remón, A., R. Zamora-Ros, M. Rotchés-Ribalta, C. Andres-Lacueva, M.A. Martínez-González, M.I. Covas, D. Corella, J. Salas-Salvadó, E. Gómez-Gracia, V. Ruiz-Gutiérrez, F.J. García de la Corte, M. Fiol, M.A. Pena, G.T. Saez, E. Ros, L. Serra-Majem, X. Pinto, J. Warnberg, R. Estruch, R.M. Lamuela-Raventos, on behalf of the PREDIMED Study Investigators, 2011. Total polyphenol excretion and blood pressure in subjects at high cardiovascular risk. Nutrition, Metabolism & Cardiovascular Diseases. 21: 323-331.

Background and aims: Dietary factors are critical for the prevention and treatment of hypertension, but data on the effects of specific nutrients on blood pressure (BP) are scarce. The aim of this study was to assess the relationship between total polyphenol excretion (TPE) in urine, as an objective measurement of total polyphenol intake and BP in an elderly population at high cardiovascular risk. Methods and results: Cross-sectional substudy of 589 high-risk participants entering in the PREDIMED trial. BP was measured and TPE was determined in urine by FolineCiocalteu assay. A significant positive association was observed between TPE in urine and daily intake of fruit and vegetables (F&V), coffee or wine after adjusting for potential confounders. The intake of 100 g of F&V (Beta=0.150;P < 0.001) had a greater contribution to TPE than 100 mL of coffee (Beta=0.141;P=0.001), and the latter two foods contributed more than the consumption of 100 mL of wine  Beta=0.120;P=0.019). An inverse association was observed between urinary TPE and the prevalence of hypertension. Participants in the highest quartile of urinary TPE had a reduced prevalence of hypertension compared to those in the lowest quartile (Odds Ratio=0.64; 95% confidence interval 0.45 to 0.92; P=0.015). Systolic and diastolic BP were inversely associated with urinary TPE after adjustment for potential confounders (P=0.024 and P=0.003, respectively). Conclusions: Polyphenol intake, assessed via TPE in urine, was negatively associated with BP levels and prevalence of hypertension in an elderly Mediterranean population at high cardiovascular risk. Participants with the highest intake of polyphenol-rich foods showed the lowest BP measurements.

Association between a healthy lifestyle and general obesity and abdominal obesity in an elderly population at high cardiovascular risk.

Bulló, M., M. Garcia-Aloy, M.A. Martínez-González, D. Corella, J.D. Fernández-Ballart, M. Fiol, E. Gómez-Gracia, R. Estruch, M. Ortega-Calvo, S. Francisco, G. Flores-Mateo, L. Serra-Majem, X. Pintó,  M.–I. Covas, E. Ros, R. Lamuela-Raventós, J. Salas-Salvadó, 2011. Association between a healthy lifestyle and general obesity and abdominal obesity in an elderly population at high cardiovascular risk. Preventive Medicine. 53:155–161.

Background: Diet, smoking and physical activity are important modifiable lifestyle factors that can influence body weight and fat accumulation. We assessed the relationship between lifestyle and obesity risk in a baseline analysis of the PREDIMED study, a randomized dietary primary prevention trial conducted in Spain. Methods: 7000 subjects at high cardiovascular risk were assessed cross-sectionally. A healthy lifestyle pattern (HLP) was determined using a score including: adherence to the Mediterranean diet, moderate alcohol consumption, expending  ≥ 200 kcal/day in leisure-time physical activity, and non-smoking. Results: Inverse linear trends were observed between the HLP-score and body-mass-index (BMI) or waist circumference (p<0.001). The BMI and waist circumference of participants with a HLP-score = 4 were, respectively, 1.3 kg/m2 (95% CI: 0.9 to 1.7) and 4.3 cm (3.1 to 5.4) lower than those of subjects with an HLP ≤ 1. The odds ratios of general obesity and abdominal obesity for an HLP score of 4 compared to an HPL score ≤ 1were 0.50 (0.42 to 0.60) and 0.51 (0.41 to 0.62), respectively. Conclusion: A combination of four healthy lifestyle behaviors was associated with a lower prevalence of general obesity and abdominal obesity in Mediterranean elderly subjects at high cardiovascular risk.

Influence of body mass index and serum lipids on the cholesterol-lowering effects of almonds in free-living individuals.

Jaceldo-Siegl, K., J. Sabate´, M. Batech, G.E. Fraser, 2011. Influence of body mass index and serum lipids on the cholesterol-lowering effects of almonds in free-living individuals. Nutrition, Metabolism & Cardiovascular Diseases. 21:S7-S13.

Background and aims: Short-term (4-9 weeks) human feeding trials have shown nut consumption to reduce serum total cholesterol (TC) and LDL-cholesterol (LDL). We hypothesized that individual levels of BMI, LDL, TC and triglycerides modify the cholesterol-lowering effect of almonds in a 24-week almond supplementation trial in a free-living population. Methods and results: We performed secondary analysis on data from a previously published study. Using a sequential study design, all participants followed their habitual diets during the first six months (control), and then consumed an almond-supplemented diet (habitual þ almonds) for another six months. 100 adults enrolled; 19 were lost to attrition. Those who completed the study were men (n=43) and women (n=38) with mean (SD) age 49.4 (13.6) years. During almond supplementation, we found statistically significant changes in TC (-0.22 mmol/L), LDL (-0.22 mmol/L), TC:HDL (-0.35), and LDL:HDL (-0.28) in participants with baseline LDL levels ≥ 3.30 mmol/L, but not among normocholesterolemic individuals. Direction and magnitude of change were similar among individuals with TC ≥ 5.20 mmol/L but not in the lower strata. Tests of interaction (diet × TC and diet × LDL) were significant. Reductions in the ratios TC:HDL, and LDL:HDL  were significant among those with BMI < 25 kg/m2, but not in heavier individuals; however, formal tests of interaction did not reach significance.

Effects of almond consumption on the reduction of LDL-cholesterol: a discussion of potential mechanisms and future research directions.

Berryman, C.E., A.G. Preston, W. Karmally, R.J. Deckelbaum, P.M. Kris-Etherton, 2011. Effects of almond consumption on the reduction of LDL-cholesterol: a discussion of potential mechanisms and future research directions. Nutrition Reviews. 69(4):171–185.

Diet plays a seminal role in the prevention and treatment of cardiovascular disease. Consumption of tree nuts has been shown to reduce low-density lipoprotein cholesterol (LDL-C), a primary target for coronary disease prevention, by 3–19%. Almonds have been found to have a consistent LDL-C-lowering effect in healthy individuals, and in individuals with high cholesterol and diabetes, in both controlled and free-living settings. Almonds are low in saturated fatty acids, rich in unsaturated fatty acids, and contain fiber, phytosterols, and plant protein. Other cardioprotective nutrients unique to almonds include α-tocopherol, arginine, magnesium, copper, manganese, calcium, and potassium. Mechanisms responsible for the LDL-C reduction observed with almond consumption are likely associated with the nutrients almonds provide. Biologically active by nature, these nutrients target primary mechanistic routes of LDL-C reduction, including decreased (re)absorption of cholesterol and bile acid, increased bile acid and cholesterol excretion, and increased LDL-C receptor activity. The nutrients present in almonds may regulate enzymes involved in de novo cholesterol synthesis and bile acid production. Research is needed to understand all mechanisms by which almonds reduce cardiovascular disease risk.

Crossover study of diets enriched with virgin olive oil, walnuts or almonds. Effects on lipids and other cardiovascular risk markers.

Damasceno, N.R.T., A. Pe´rez-Heras, M. Serra, M. Cofa´n, A. Sala-Vila, J. Salas-Salvado´, E. Ros, 2011. Crossover study of diets enriched with virgin olive oil, walnuts or almonds. Effects on lipids and other cardiovascular risk markers. Nutr Metab Cardiovasc Dis. 21 (Suppl 1):S14-20.

Background and aims: Virgin olive oil (VOO) and nuts are basic components of the Mediterranean diet, a heart-healthy dietary pattern. Nuts have well known cholesterol lowering effects, while evidence is unclear for VOO. We designed a study in hypercholesterolemic patients to assess the effects on serum lipids and other intermediate markers of cardiovascular risk of replacing 40% of the fat in the background diet with VOO, walnuts or almonds. Methods and Results: After a 4 week run-in period with a healthy diet, eligible candidates were randomized into three diet sequences in a crossover design, with a common background diet enriched with VOO, walnuts or almonds, lasting 4 weeks each. Outcomes were changes of serum lipids and oxidation and inflammation markers, measured by standard methods. Plasma fatty acids were determined by gas chromatography to assess compliance. In 18 participants completing the study (9 women, mean age 56 y, BMI 25.7 kg/m2), LDL cholesterol was reduced from baseline by 7.3%, 10.8% and 13.4% after the VOO, walnut and almond diets, respectively (P Z 0.001, Friedman test). Total cholesterol and LDL/HDL ratios decreased in parallel. LDL-cholesterol decreases were greater than predicted from dietary fatty acid and cholesterol exchanges among diets. No changes of other lipid fractions, oxidation analytes or inflammatory biomarkers were observed. Plasma fatty acid changes after each diet sequence supported good compliance.