Dietary nitrate modulates cerebral blood flow parameters and cognitive performance in humans

A double-blind, placebo-controlled, crossover investigation

Emma Wightman, Crystal Haskell-Ramsay, Kevin THOMPSON, Jamie Blackwell, Paul Winyard, Joanne Forster, Andrew Jones, David Kennedy

    Research output: Contribution to journalArticle

    46 Citations (Scopus)

    Abstract

    Nitrate derived from vegetables is consumed as part of a normal diet and is reduced endogenously via nitrite to nitric oxide. It has been shown to improve endothelial function, reduce blood pressure and the oxygen cost of sub-maximal exercise, and increase regional perfusion in the brain. The current study assessed the effects of dietary nitrate on cognitive performance and prefrontal cortex cerebral blood-flow (CBF) parameters in healthy adults. In this randomised, double-blind, placebo-controlled, parallel-groups study, 40 healthy adults received either placebo or 450. ml beetroot juice (~. 5.5. mmol nitrate). Following a 90. minute drink/absorption period, participants performed a selection of cognitive tasks that activate the frontal cortex for 54. min. Near-Infrared Spectroscopy (NIRS) was used to monitor CBF and hemodynamics, as indexed by concentration changes in oxygenated and deoxygenated-haemoglobin, in the frontal cortex throughout. The bioconversion of nitrate to nitrite was confirmed in plasma by ozone-based chemi-luminescence. Dietary nitrate modulated the hemodynamic response to task performance, with an initial increase in CBF at the start of the task period, followed by consistent reductions during the least demanding of the three tasks utilised. Cognitive performance was improved on the serial 3s subtraction task. These results show that single doses of dietary nitrate can modulate the CBF response to task performance and potentially improve cognitive performance, and suggest one possible mechanism by which vegetable consumption may have beneficial effects on brain function
    Original languageEnglish
    Pages (from-to)149-158
    Number of pages10
    JournalPhysiology and Behavior
    Volume149
    DOIs
    Publication statusPublished - 1 Oct 2015

      Fingerprint

    Cite this