Effects of walnut intake on blood pressure: A systematic review and meta‐analysis of randomized controlled trials

Abstract

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 walnutenhanced 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 metaanalysis does not support walnut consumption as a BP-lowering strategy. K E Y W O R D S blood pressure, cardiovascular risk, diastolic blood pressure, meta-analysis, systolic blood pressure, walnut 1 | INTRODUCTION Hypertension or high blood pressure (BP) is a key modifiable risk factor for cardiovascular diseases (CVD), hence being the main cause of global morbidity and mortality (Bochud, Marques-Vidal, Burnier, &

Walnut intake, cognitive outcomes and risk factors: a systematic review and meta-analysis

“…Previous systematic reviews and meta-analyses did not show an effect of dietary walnut intake on blood pressure [71,74], or oxidative stress [74]. However, the meta-analysis by Guasch-Ferr e et al [74] found that walnut consumption resulted in significantly higher reduction of total cholesterol, LDL cholesterol, triglycerides, ApoA, and ApoB.…”

“…In addition to cognitive function and related outcomes, we aimed to evaluate the effect of walnut on risk factors for cognitive decline, including alterations in blood lipids, glucose metabolism, blood pressure, endothelial function, inflammation, and oxidative stress [2][3][4]10]. Since systematic reviews and metaanalyses examining the effects of walnuts on blood lipids, blood pressure [20,71], oxidative stress [20] and endothelial function [21,72] have been published prior to the end of our search date (April 2020), we report a systematic review and meta-analysis of measures of inflammation and glucose homeostasis. Our meta-analyses found no significant effect of walnut consumption on HbA1c or HOMA-IR across included studies.…”

Beyond Fish Oil Supplementation: The Effects of Alternative Plant Sources of Omega-3 Polyunsaturated Fatty Acids upon Lipid Indexes and Cardiometabolic Biomarkers—An Overview

“…The blood pressure of all participants in that study was monitored by the 24-h ambulatory blood pressure monitoring, which is considered the gold standard in the diagnosis of hypertension [ 64 ]. In contrast, a recent meta-analysis [ 65 ] did not support walnut consumption per se as a blood pressure-lowering strategy. Despite being a meta-analysis, that study [ 65 ] may have had a few limitations due to heterogeneity.…”

“…In contrast, a recent meta-analysis [ 65 ] did not support walnut consumption per se as a blood pressure-lowering strategy. Despite being a meta-analysis, that study [ 65 ] may have had a few limitations due to heterogeneity. The results of Domènech et al [ 63 ] provide what appears to be reliable evidence, based mainly on its long-term duration and sample size.…”

Identifying Usual Food Choice Combinations With Walnuts: Analysis of a 2005–2015 Clinical Trial Cohort of Overweight and Obese Adults

“…Although walnuts are rich in unsaturated fats, minerals, vitamins, fiber, and polyphenols, they stand out for their high polyunsaturated fatty acids content ( 25 ). Literature has suggested that the intake of walnuts was associated with decreasing the risk of cardiometabolic diseases ( 26 – 30 ). Thus, the aim of this study was to explore the food choices in relation to walnuts at meal occasions as reported by a sample of overweight and obese volunteers in weight loss trials.…”