Post by the Scribe on Feb 26, 2022 4:51:33 GMT
Diets Containing Pistachios Reduce Systolic Blood Pressure and Peripheral Vascular Responses to Stress in Adults With Dyslipidemia
www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC3862178/
Perspectives
Epidemiological studies show that individuals who regularly consume nuts are at lower risk of cardiovascular morbidity and mortality compared with individuals who do not eat nuts regularly.1–5 The American Heart Association recommends consuming ≥4 servings per week of nuts, legumes, and seeds.23,29 The 2010 Dietary Guidelines for Americans advises consumption of a variety of high-protein plant foods, including unsalted nuts and seeds.30 Taken together with improvements in dyslipidemia and antioxidant activity reported previously, reductions in peripheral vascular constriction (and the resulting decrease in hemodynamic load) may be important contributors to lower CVD risk in nut consumers. Future studies should examine the underlying mechanisms for peripheral vasodilation reported here and also seek to identify the bioactive components in pistachios that mediate this response. Furthermore, given the cost of certain nuts and the energy density of nuts, additional research is needed to establish the lowest required dose to achieve a reduction in left ventricular workload.
Novelty and Significance
What is new?
Moderate fat diets containing pistachios reduced BP and vascular resistance during acute stress.
Endothelial function was not affected by the pistachio diets
What is relevant?
Reductions in hemodynamic load during stress may be a mechanism through which nut consumption confers cardioprotection.
It is possible to integrate nuts into the habitual diet without weight gain, although this requires reducing intake of other high-fat/high-calorie foods in exchange for nuts.
Summary
Taken together with improvements in dyslipidemia and antioxidant activity reported previously, reductions in peripheral vascular constriction (and the resulting decrease in hemodynamic load) may be important contributors to lower CVD risk in nut consumers.
Abstract
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·s×cm−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.
Keywords: diet, stress, blood pressure, endothelium, total peripheral resistance, nuts, pistachios
Nut consumption is associated with significant reductions in cardiovascular disease (CVD) risk and all-cause mortality.1–5 In the Nurses' Health Study, women who consumed >2 servings of nuts per week had an 18% reduction in cardiac death compared with women who did not eat nuts regularly.5 In short-term, randomized trials, almonds,6,7 walnuts,8–10 and pistachios11,12 significantly reduced low-density lipoprotein (LDL) cholesterol and total cholesterol, when compared with a typical Western diet or diets low in saturated fat (SFA; for review, see Sabate et al13). We have shown previously that including 1 or 2 servings per day of pistachios in a healthy diet reduced LDL cholesterol by 9% to 12%.11 The effects of pistachios on the ratio of LDL cholesterol to high-density lipoprotein cholesterol were dose dependent, with larger improvements in LDL cholesterol/high-density lipoprotein cholesterol11 and greater reductions in oxidized LDL14 when participants consumed 2 servings per day.
In 1 epidemiological study, nut intake was associated with lower blood pressure (BP) and lower risk of hypertension.15 However, the protective effect of nuts was limited to lean individuals, and sodium was not considered (for review, see Casas-Agustench et al16). Relatively few clinical studies of nuts have reported BP data, and findings have been inconsistent, with some studies reporting significant reductions in BP when nuts are consumed,17,18 whereas others report no significant change.6,9 Little is known about the mechanism(s) that may underlie the relationship between nut consumption and BP, and dose-response relationships have not been studied. Based on our previous work with walnuts,18 we hypothesized that lower peripheral vascular resistance may mediate the relationship between nut consumption and BP. Furthermore, given the putative role of stress in the development of hypertension,19,20 it is important to confirm whether reductions in BP persist during exposure to acute stress. Three previous studies have shown significant improvements in flow-mediated dilation (FMD), a measure of endothelial function, after walnut consumption.21–23 One unrandomized trial suggests that pistachios also increase FMD.24 We hypothesized that adding pistachios to a healthy diet would lower BP at rest and during stress, and that this change would be mediated by reductions in peripheral vascular resistance and increases in FMD.
www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC3862178/
Perspectives
Epidemiological studies show that individuals who regularly consume nuts are at lower risk of cardiovascular morbidity and mortality compared with individuals who do not eat nuts regularly.1–5 The American Heart Association recommends consuming ≥4 servings per week of nuts, legumes, and seeds.23,29 The 2010 Dietary Guidelines for Americans advises consumption of a variety of high-protein plant foods, including unsalted nuts and seeds.30 Taken together with improvements in dyslipidemia and antioxidant activity reported previously, reductions in peripheral vascular constriction (and the resulting decrease in hemodynamic load) may be important contributors to lower CVD risk in nut consumers. Future studies should examine the underlying mechanisms for peripheral vasodilation reported here and also seek to identify the bioactive components in pistachios that mediate this response. Furthermore, given the cost of certain nuts and the energy density of nuts, additional research is needed to establish the lowest required dose to achieve a reduction in left ventricular workload.
Novelty and Significance
What is new?
Moderate fat diets containing pistachios reduced BP and vascular resistance during acute stress.
Endothelial function was not affected by the pistachio diets
What is relevant?
Reductions in hemodynamic load during stress may be a mechanism through which nut consumption confers cardioprotection.
It is possible to integrate nuts into the habitual diet without weight gain, although this requires reducing intake of other high-fat/high-calorie foods in exchange for nuts.
Summary
Taken together with improvements in dyslipidemia and antioxidant activity reported previously, reductions in peripheral vascular constriction (and the resulting decrease in hemodynamic load) may be important contributors to lower CVD risk in nut consumers.
Abstract
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·s×cm−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.
Keywords: diet, stress, blood pressure, endothelium, total peripheral resistance, nuts, pistachios
Nut consumption is associated with significant reductions in cardiovascular disease (CVD) risk and all-cause mortality.1–5 In the Nurses' Health Study, women who consumed >2 servings of nuts per week had an 18% reduction in cardiac death compared with women who did not eat nuts regularly.5 In short-term, randomized trials, almonds,6,7 walnuts,8–10 and pistachios11,12 significantly reduced low-density lipoprotein (LDL) cholesterol and total cholesterol, when compared with a typical Western diet or diets low in saturated fat (SFA; for review, see Sabate et al13). We have shown previously that including 1 or 2 servings per day of pistachios in a healthy diet reduced LDL cholesterol by 9% to 12%.11 The effects of pistachios on the ratio of LDL cholesterol to high-density lipoprotein cholesterol were dose dependent, with larger improvements in LDL cholesterol/high-density lipoprotein cholesterol11 and greater reductions in oxidized LDL14 when participants consumed 2 servings per day.
In 1 epidemiological study, nut intake was associated with lower blood pressure (BP) and lower risk of hypertension.15 However, the protective effect of nuts was limited to lean individuals, and sodium was not considered (for review, see Casas-Agustench et al16). Relatively few clinical studies of nuts have reported BP data, and findings have been inconsistent, with some studies reporting significant reductions in BP when nuts are consumed,17,18 whereas others report no significant change.6,9 Little is known about the mechanism(s) that may underlie the relationship between nut consumption and BP, and dose-response relationships have not been studied. Based on our previous work with walnuts,18 we hypothesized that lower peripheral vascular resistance may mediate the relationship between nut consumption and BP. Furthermore, given the putative role of stress in the development of hypertension,19,20 it is important to confirm whether reductions in BP persist during exposure to acute stress. Three previous studies have shown significant improvements in flow-mediated dilation (FMD), a measure of endothelial function, after walnut consumption.21–23 One unrandomized trial suggests that pistachios also increase FMD.24 We hypothesized that adding pistachios to a healthy diet would lower BP at rest and during stress, and that this change would be mediated by reductions in peripheral vascular resistance and increases in FMD.