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Effects of walnut intake on blood pressure: A systematic review and meta‐analysis of randomized controlled trials
Author(s) -
Li Jiayang,
Jiang Bo,
O. Santos Heitor,
Santos Dinamene,
Singh Ambrish,
Wang Lei
Publication year - 2020
Publication title -
phytotherapy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 129
eISSN - 1099-1573
pISSN - 0951-418X
DOI - 10.1002/ptr.6740
Subject(s) - medicine , randomized controlled trial , meta analysis , blood pressure , clinical trial , ingestion , subgroup analysis , surgery
The impact of walnuts on blood pressure (BP) is not a well‐established fact. Although several studies have assessed the effects of walnut consumption on BP, results are conflicting. Thus, we examined the effects of walnut doses and length of supplementation on BP. Biomedical databases were searched for published trials that compared walnut‐enhanced diet to control diet. Eighteen trials met eligibility criteria ( n = 1,799). Overall, walnut consumption neither did alter SBP (weighted mean difference [WMD]: 0.08 mmHg; 95% CI: −0.69, 0.85) nor DBP (WMD: 0.08 CI: −0.26, 0.42). In subgroup analyses, walnut ingestion ≤40 g was statistically correlated with reduction in SBP (WMD: −0.53 mmHg, 95% CI: −0.79, −0.26) and DBP (WMD: −0.191 mmHg, 95% CI: −0.384, −0.034). Moreover, the length of intervention ≥8 weeks was linked to a significant reduction in SBP (WMD: −1.18 mmHg, 95% CI: −1.30, −1.06). Following dose–response evaluation, walnut intake significantly changed SBP ( p = .015) and DBP ( p = .026) through a nonlinear fashion at walnut dose up to 40 g/d. Nevertheless, these statistical results cannot be translated into clinical practice, once the changes expressed as WMD are slight taking into consideration the absolute values of BP categories. In conclusion, this meta‐analysis does not support walnut consumption as a BP‐lowering strategy.