A recent double-blind, randomized, placebo-controlled trial investigated the effect of a branded beetroot extract on cognitive health. The intervention was consumed as a chewable tablet.
A recent double-blind, randomized, placebo-controlled two-period crossover trial investigated the effect of a branded beetroot extract on cognitive health. Forty-four subjects were randomized to receive either four chewable tablets containing a placebo or four chewable tablets containing 3 g of beetroot extract 90 minutes prior to neuropsychological tests. The beetroot extract is sold under the name RedNite by Enovate Biolife (Wilmington, DE) and is standardized for 1.5%-2.75% natural nitrate. After a four-day washout period, subjects switched interventions and were once again subjected to neuropsychological tests.
Results showed that subjects taking the beetroot extract saw significant improvements in memory consolidation in the short and long-term demonstrated by the Rey Auditory Verbal Learning Test, in which these subjects saw a 20.69% and 12.34% increase in intermediate and delayed recall, respectively. Researchers also detected an enhancement of 2.57% in frontal lobe function in subjects taking the beetroot extract and an enhancement of 11.16% in cognitive flexibility. There were no significant changes in verbal memory of short-term digits, working memory, and information processing speed, while mood and anxiety outcomes were mixed.
The researchers also noted that the beetroot extract was well tolerated and palatable. “[Palatability] should not be underestimated, not only for what concerns the compliance in use, but also this has allowed a longer stay in the mouth with consequent greater exposure to the salivary microbiota, with the consequent possible greater conversion of [nitrate] into [nitrogen dioxide] and absorption in the plasma circulation,” wrote the researchers. “It might be possible that the increase in cerebral blood flow, and thereby the higher nutrient supply, after the supplementation with the chewable [nitrate]-rich BR-based product might have impacted the cognitive performance.”
The study has a number of limitations that future research should correct. For example, in this current study, the researchers did not measure blood concentrations of nitrate, nitrogen dioxide or nitric oxide to ensure the metabolite was increased post-supplementation. Nor did the researchers employ near-infrared spectroscopy to detect changed in cerebral blood flow, which is an indirect measure of brain activity. Finally, the subjects ranged in age, which could lead to differenced in cognitive performance that were not counterbalanced by the supplement.
Vaccaro, M.G.; Innocenti, B.; Cione, E.; Gallelli, L.; De Sarro, G.; Bonilla, D.A.; Cannataro, R. Acute Effects of a Chewable Beetroot‑Based Supplement on Cognitive Performance: A Double‑Blind Randomized Placebo‑Controlled Crossover Clinical Trial. European Journal of Nutrition. 2023. Article ASAP. DOI: 10.1007/s00394-023-03265-y