Abstract: In recent years, there has been a notable surge in the popularity of beetroot-based dietary supplements, driven by their rich nitrate composition. Several types of beetroot-based dietary supplements can be found in markets worldwide; however, ensuring the safety of dietary supplements is a crucial consideration, as there is limited evidence on their safety, especially for older populations. Therefore, the purpose of the current study was to evaluate the safety and tolerability of a nitrate-rich beetroot extract in older participants taking supplements over 12 weeks. The participants were randomly assigned to receive 20 g daily of beetroot extract or a matching placebo. The safety and tolerability of the supplementation were evaluated as the occurrence of adverse events and anthropometric, biochemical, and hemodynamic parameters were measured. No serious adverse events were reported in any group. Anthropometric, biochemical, and hemodynamic parameter changes between the baseline and the end of the study were not statistically significant in either group. However, interestingly, the group receiving beetroot extract supplementation exhibited a notable increase in plasma nitrate levels (p = 0.076, f = 0.50) and showed a decrease in insulin levels (p = 0.026, f = 0.59).
In conclusion, we found that 20 g of beetroot extract supplementation for 12 weeks was safe and well tolerated in older participants. It was necessary to conduct this study before investigating the efficacy of this dietary supplement in a larger sample of older people to detect changes in other health parameters, such as vascular function and muscle quality, and to promote the overall safety and efficacy of beetroot-based dietary supplements.
Keywords: dietary supplements; standardized beetroot extract; nitrate; food safety 1. Introduction
Evaluation of 12-Week Standardized Beetroot Extract Supplementation in Older Participants: A Preliminary Study of Human Health Safety Vivian dos Santos Pinheiro , Olavo João Frederico Ramos Junior, Caroline Flach Ortmann, Anurag Pande, Carlos Adam Conte-Junior and Thiago Silveira Alvares, Nutrients 2024, 16, 1942

Abstract : Most outcomes of COVID-19 are associated with dysfunction of the vascular system, particularly in the lung. Inhalation of nitric oxide (NO) gas is currently being investigated as a treatment for patients with moderate to severe COVID-19. In addition to the expected vasodilation effect, it has been also suggested that NO potentially prevents infection by SARS-CoV-2. Since NO is an unstable radical molecule that is easily oxidized by multiple mechanisms in the human body, it is practically difficult to control its concentration at lesions that need NO. Inorganic nitrate and/or nitrite are known as precursors of NO that can be produced through chemical as well enzymatic reduction. It appears that this NO synthase (NOS)-independent mechanism has been overlooked in the current developing of clinical treatments. Here, I suggest the missing link between nitrate and COVID-19 in terms of hypoxic NO generation.
Keywords : Covid-19 Nitrate Nitric oxide Nitrite Vitamin C SARS-CoV-2
Blood nitrate and nitrite modulating nitric oxide bioavailability: Potential therapeutic functions in COVID-19, Elsevier Inc., Hideo Yamasaki Faculty of Science, University of the Ryukyus, 13 July 2020