A Single Dose of Beetroot Gel Rich in Nitrate Does Not Improve Performance but Lowers Blood Glucose in Physically Active Individuals.

Background. Beetroot consumption has been proposed to improve exercise performance, since the nitrate content of this food is able to stimulate the synthesis of nitric oxide. Objective. The acute effect of 100 g of a beetroot gel containing ~10 mmol of nitrate was tested on the nitric oxide synthesis, on metabolic and biochemical parameters, and on performance in physically active individuals. Methods. Through a double blind, crossover, placebo-controlled study, 25 healthy runners ingested a single dose of beetroot and placebo gels. Participants performed an aerobic exercise protocol on a treadmill (3 min warm-up of 40% peak oxygen consumption, 4 min at 90% of gas exchange threshold I and 70% (Δ) maximal end speed until volitional fatigue). Results. Urinary levels of nitrite and nitrate increased after 90 min of beetroot gel ingestion. Plasma glucose concentrations lowered after the exercise and the decrease was maintained for 20 min. Systolic and diastolic blood pressures, serum cortisol, and blood lactate were not altered after the beetroot gel ingestion compared to a placebo gel. Conclusion. The single dose of beetroot gel provoked an increase of nitric oxide synthesis although no improvement on the physical performance of athletes during aerobic submaximal exercise was observed.

Development of a beetroot-based nutritional gel containing high content of bioaccessible dietary nitrate and antioxidants.

Beetroot, a food rich in nitrate and antioxidants has gained attention because of its potential effect on improving cardiovascular health and exercise performance. This work had the purpose of developing a beetroot-based nutritional gel (BG) and estimating the in vitro bioaccessibility of the nitrate, total antioxidant capacity (TAC), total phenolic (TP) and potassium content, as compared to beetroot juice (BJ). Nitrate was assessed by a high-performance liquid chromatography system, TAC was assessed using the Trolox equivalent antioxidant capacity (TEAC) assay and TP was measured using the Folin-Ciocalteu method before and after an in vitro digestion. Significantly higher values of nitrate, TEAC, TP and potassium before and after digestion were observed in BG as compared to BJ. The results suggest a new nutritional strategy to give high contents of bioaccessible nutrients (nitrate, antioxidants and potassium) that are potentially relevant to improve cardiovascular health and exercise performance.

Comparison of total antioxidant potential, and total phenolic, nitrate, sugar, and organic acid contents in beetroot juice, chips, powder, and cooked beetroot.

Beetroot is a vegetable rich in nitrate (NO3 -), antioxidants and phenolic compounds that are related to improvements in cardiovascular function and exercise performance. However, it is unknown if convenient forms of beetroot administration provide different amounts of these nutrients. The total antioxidant potential (TAP), total phenolic (TPC), sugar, organic acid, and NO3 - contents of beetroot juice (BJ), chips (BC), powder (BP), and cooked beetroot (CB) were compared. Significant (p<0.01) differences in chemical compositions and functional properties were found between beetroot formulations. Higher amounts of TAP and organic acids were observed in BC and BP, compared with the other formulations. BJ exhibited the highest contents of total sugars, TPC, and NO3 -. All beetroot formulations were suitable and advantageous based on taste preferences and convenience for consumers and for nutrient amounts required to meet dietary recommendations.