A randomized clinical trial of beetroot juice consumption on inflammatory markers and oxidative stress in patients with type 2 diabetes

Abstract

Background/Objectives Oxidative stress and chronic in ammation are both major underlying factors for the initiation and progression of diabetes as well as for the development of long-term diabetes-related consequences in patients with type 2 diabetes mellitus (T2DM). This study was designed to evaluate the effects of concentrated beetroot juice (BJ) consumption on oxidative stress and in ammatory markers in patients with T2DM.Methods In this 12-weeks randomized clinical trial, forty-six patients with T2DM were randomly assigned to either the concentrated BJ or the control group. The BJ group received 12 ml concentrated beetroot juice twice daily, whereas the control group received no intervention. At baseline and the end of week 12, plasma levels of malondialdehyde (MDA), high sensitive C-reactive protein (hs-CRP), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), and nuclear factor-κB (NF-κB) were measured.Results Compared with control group, concentrated BJ reduced IL-6 (−0.1 vs. 0.83, p = .001), TNF-α (−1.28 vs. 5.51, p = .001), and NF-κB (−0.03 vs. 0.36, p = .005) after 12 weeks intervention; plasma concentration of MDA and hs-CRP did not change between groups after intervention. Intra-group comparison with paired t-test disclosed that daily BJ consumption could not change oxidative stress and in ammatory markers except for TNF-α compared with baseline values. However, the concentrations of IL-6, TNF-α, and NF-κB increased signi cantly in the control group at the end of week 12 compared to baseline (p = .001, p = .001, p = .021, respectively).Conclusions In conclusion, our study indicates that daily consumption of 24 ml concentrated BJ to patients with T2DM reduces the concentrations of some in ammatory markers including IL-6, TNF-α, and NF-κB which are involved in the pathogenesis of complications of T2DM.Trial Registration This study was registered at the Iranian Registry of Clinical Trials (IRCT) with the following identi cation: IRCT20150815023617N5.

The effects of beetroot and nitrate supplementation on body composition: a GRADE-assessed systematic review and meta-analysis

“…The trials were carried out among triathletes (29) , baseball players (27) , elite fencers (14,25) , older healthy participants (21) , elderly men and women (28) . In addition, the studies enrolled patients with pre-hypertension (26,31) , hypertension (30) , non-alcoholic fatty liver disease (24) , type 2 diabetes mellitus (23) and polycystic ovary syndrome (22) . A daily dose of BR or nitrate supplements was between 2 and 200 g. Table 2 presents the risk of bias assessment in the twelve included studies.…”

“…Two RCTs (23,31) with three arms ( n 98) reported the impact of BR or nitrate intake on the WHR of participants (intervened v . untreated group) (Fig.…”

“…The majority of the included studies in the current meta-analysis were conducted to determine the effects of BRJ on inflammation, oxidative stress, lipid profile levels, blood pressure and liver enzymes in patients; thus, none of these studies was designed to assess the effect of partial substitution of carbohydrate intake with BR or nitrate on weight loss. In this regard, one of the included RCT was conducted to evaluate the effects of BRJ on oxidative stress and inflammatory markers in patients with type 2 diabetes mellitus who were asked to maintain their regular dietary habits during the study (23) . In that study, supplementation with 24 ml BRJ for 12 weeks did not show any changes in body weight, BMI, WC and WHR compared with the control group; no changes in body composition indices may partially be explained by no differences in energy content intake between the two groups and in each group at the end of the study (23) .…”

“…In this regard, one of the included RCT was conducted to evaluate the effects of BRJ on oxidative stress and inflammatory markers in patients with type 2 diabetes mellitus who were asked to maintain their regular dietary habits during the study (23) . In that study, supplementation with 24 ml BRJ for 12 weeks did not show any changes in body weight, BMI, WC and WHR compared with the control group; no changes in body composition indices may partially be explained by no differences in energy content intake between the two groups and in each group at the end of the study (23) . In another included RCT among patients with non-alcoholic fatty liver disease, supplementation with 5 mg of BR powder daily for 3 months could reduce liver enzyme levels, lipid profiles and liver size compared with controls, but BMI remained unchanged (24) .…”

“…A total of twelve RCTs involving 500 participants (301 cases and 299 controls) were included in this meta-analysis (14,(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31) . Six of the studies had two trial arms (14,25,26,28,29,31) .…”