Changes in Oxidative Stress, Inflammation, and Muscle Damage Markers Following Diet and Beetroot Juice Supplementation in Elite Fencers

Abstract

<jats:p>The aim of this study was to assess the impact of diet and active substances in beetroot juice on the parameters of oxidative stress, inflammation, and muscle damage as well as on the maximum rate of oxygen uptake (VO2max) in elite fencers (10 women, 10 men). Athletes during four weeks realized dietary recommendations (ID) and, after that, diet with freeze-dried beetroot juice supplementation (ID&amp;BEET). At baseline and after each stage, fasting antioxidants, biomarkers of oxidative stress, inflammation, and skeletal muscle damage were measured, and a VO2max test was performed. Only after ID&amp;BEET was a significant increase of VO2max observed, and changes of this parameter were negatively related with changes of serum lactate dehydrogenase (∆LDH) activity, as well as with serum ∆β-carotene and malondialdehyde concentration (∆MDA). Additionally, positive relationships were observed between ∆β-carotene versus changes of the serum concentration of advanced oxidation protein products (∆AOPP), changes of serum glutathione peroxidase activity (∆GPx3) versus both changes of physical activity level and ∆LDH, as well as erythrocyte glutathione peroxidase activity (∆GPx1) versus ∆LDH. To summarize, we showed that long-term beetroot juice supplementation increases lipid peroxidation, and improvement of VO2max after ID&amp;BEET seems to be dependent on LDH activity, as well as on the serum concentration of MDA and β-carotene.</jats:p>

Dietary Supplementation for Attenuating Exercise-Induced Muscle Damage and Delayed-Onset Muscle Soreness in Humans

“…The authors of a previous study speculated that beetroot juice consumption might have increased physical activity, ultimately increasing oxidative stress. Additionally, a significant increase in VO 2max was observed after ingestion of beetroot juice without attenuated muscle damage markers, such as CK and LDH [ 68 ].…”

“…One parallel study showed no effect on oxidative stress [ 63 ], whereas one crossover study showed that beetroot juice increased oxidative stress [ 68 ]. Previous studies demonstrated that beetroot juice had no effect on inflammatory responses (IL-6, IL-8, CRP, and TNF-α) following exercise modalities (sprint, plyometric, intermittent, and endurance exercise) regardless of parallel [ 61 , 62 , 63 , 64 ] or crossover [ 67 , 68 ] study design. From these results, it is thought that the antioxidant and anti-inflammatory effects of beetroot juice after exercise may be minimal based on the blood indices.…”

Antioxidant Responses in Hypertensive Postmenopausal Women after Acute Beetroot Juice Ingestion and Aerobic Exercise: Double Blind and Placebo‐Controlled Crossover Trial

“…In vitro [40], it was observed that a shot of BJ manages to supply a large number of bioaccessible antioxidants in gastric and duodenal cells, hypothesizing that this would be an interesting strategy to increase the body's antioxidant status. Some authors showed, in a study with diet control over four weeks of BJ [41], an increase in lipid peroxidation, indicating a change in oxidative behavior.…”

Possible Effects of Beetroot Supplementation on Physical Performance Through Metabolic, Neuroendocrine, and Antioxidant Mechanisms: A Narrative Review of the Literature

“…Kozlowska et al stated that the chronic BR consumption enhances lipid peroxidation, and improvement of VO 2max after the BR supplement consumption seems to be dependent on baseline lactic acid dehydrogenase (LDH) activity, and also, on the serum concentrations of malondialdehyde (MDA) and β-carotene. It is suggested that alterations in the ergogenic effect of BR are negatively dependent to alter in serum concentration of MDA, β-carotene, and the activity of LDH ( 57 ). Singh et al stated that the BR ingestion significantly declined the stress markers of plasma hydroperoxides and improves the antioxidant status ( 40 ).…”