TY - JOUR

T1 - The effect of tree nut, peanut, and soy nut consumption on blood pressure

T2 - A systematic review and meta-analysis of randomized controlled clinical trials

AU - Mohammadifard, Noushin

AU - Salehi-Abargouei, Amin

AU - Salas-Salvadó, Jordi

AU - Guasch-Ferré, Marta

AU - Humphries, Karin

AU - Sarrafzadegan, Nizal

N1 - Publisher Copyright: © 2015 American Society for Nutrition.

PY - 2015

Y1 - 2015

N2 - Background: Although several studies have assessed the effects of nut consumption (tree nuts, peanuts, and soy nuts) on blood pressure (BP), the results are conflicting. Objective: The aim was to conduct a systematic review and metaanalysis of published randomized controlled trials (RCTs) to estimate the effect of nut consumption on BP. Design: The databases MEDLINE, SCOPUS, ISIWeb of Science, and Google Scholar were searched for RCTs carried out between 1958 and October 2013 that reported the effect of consuming single or mixed nuts (including walnuts, almonds, pistachios, cashews, hazelnuts, macadamia nuts, pecans, peanuts, and soy nuts) on systolic BP (SBP) or diastolic BP (DBP) as primary or secondary outcomes in adult populations aged $18 y. Relevant articles were identified by screening the abstracts and titles and the full text. Studies that evaluated the effects for ,2 wk or in which the control group ingested different healthy oils were excluded. Mean 6 SD changes in SBP and DBP in each treatment group were recorded for meta-analysis. Results: Twenty-one RCTs met the inclusion criteria. Our findings suggest that nut consumption leads to a significant reduction in SBP in participants without type 2 diabetes [mean difference (MD): 21.29; 95% CI: 22.35, 20.22; P = 0.02] but not in the total population. Subgroup analyses of different nut types suggest that pistachios, but not other nuts, significantly reduce SBP (MD: 21.82; 95% CI: 22.97, 20.67; P = 0.002). Our study suggests that pistachios (MD: 20.80; 95% CI: 21.43, 20.17; P = 0.01) and mixed nuts (MD: 21.19; 95% CI: 22.35, 20.03; P = 0.04) have a significant reducing effect on DBP. We found no significant changes in DBP after the consumption of other nuts. Conclusions: Total nut consumption lowered SBP in participants without type 2 diabetes. Pistachios seemed to have the strongest effect on reducing SBP and DBP. Mixed nuts also reduced DBP.

AB - Background: Although several studies have assessed the effects of nut consumption (tree nuts, peanuts, and soy nuts) on blood pressure (BP), the results are conflicting. Objective: The aim was to conduct a systematic review and metaanalysis of published randomized controlled trials (RCTs) to estimate the effect of nut consumption on BP. Design: The databases MEDLINE, SCOPUS, ISIWeb of Science, and Google Scholar were searched for RCTs carried out between 1958 and October 2013 that reported the effect of consuming single or mixed nuts (including walnuts, almonds, pistachios, cashews, hazelnuts, macadamia nuts, pecans, peanuts, and soy nuts) on systolic BP (SBP) or diastolic BP (DBP) as primary or secondary outcomes in adult populations aged $18 y. Relevant articles were identified by screening the abstracts and titles and the full text. Studies that evaluated the effects for ,2 wk or in which the control group ingested different healthy oils were excluded. Mean 6 SD changes in SBP and DBP in each treatment group were recorded for meta-analysis. Results: Twenty-one RCTs met the inclusion criteria. Our findings suggest that nut consumption leads to a significant reduction in SBP in participants without type 2 diabetes [mean difference (MD): 21.29; 95% CI: 22.35, 20.22; P = 0.02] but not in the total population. Subgroup analyses of different nut types suggest that pistachios, but not other nuts, significantly reduce SBP (MD: 21.82; 95% CI: 22.97, 20.67; P = 0.002). Our study suggests that pistachios (MD: 20.80; 95% CI: 21.43, 20.17; P = 0.01) and mixed nuts (MD: 21.19; 95% CI: 22.35, 20.03; P = 0.04) have a significant reducing effect on DBP. We found no significant changes in DBP after the consumption of other nuts. Conclusions: Total nut consumption lowered SBP in participants without type 2 diabetes. Pistachios seemed to have the strongest effect on reducing SBP and DBP. Mixed nuts also reduced DBP.

KW - Almond

KW - Blood pressure

KW - Cashew

KW - Nut

KW - Pistachio

KW - Randomized controlled trials

KW - Walnut

U2 - 10.3945/ajcn.114.091595

DO - 10.3945/ajcn.114.091595

M3 - Journal article

C2 - 25809855

AN - SCOPUS:84929660820

VL - 101

SP - 966

EP - 982

JO - American Journal of Clinical Nutrition

JF - American Journal of Clinical Nutrition

SN - 0002-9165

IS - 5

ER -