title: Effects of a Dietary Beetroot Juice Treatment on Systemic and Cerebral Haemodynamics- A Pilot Study.
abstract: BACKGROUND
  Beetroot Juice (BJ) contains dietary nitrates that increase the blood Nitric Oxide (NO) level, decrease Blood Pressure (BP), increase athletic performance and improve cognitive functions but the mechanism remains unclear. Ultrasonographic measurement of middle cerebral artery blood flow velocity with computation of Cerebral Augmentation Index (CAIx) is a measure of the reflected flow signal, modulated by changes in cerebrovascular resistance and compliance.
  
  
  OBJECTIVE
  This pilot study tests the hypothesis that ingestion of an amount of BJ sufficient to raise the blood NO level two-to three-fold, decreases Transcranial Doppler (TCD) measured CAIx.
  
  
  METHODS
  Ten healthy young-adult African-American women were studied at two levels of submaximal exercise, 40% and 80% of their predetermined peak oxygen consumptions. The subjects ingested nitrate-free orange juice (OJ, control) and an isocaloric BJ beverage (1.5 mg/mL nitrate, 220 Cal), on different days, 1-2 weeks apart.
  
  
  RESULTS
  The BJ treatment increased blood NO and decreased systolic BP at rest and at the two levels of exercise. The BJ treatment decreased CAIx only at the two levels of exercise (from 79 ± 2% to 62 ± 2% and from 80 ± 2% to 60 ± 3%, p<0.05). Exercise increased TCD-measured resistance and pulsatility indices (RIx, PIx) without changing AIx. The BJ treatment had no effect on RIx and PIx.
  
  
  CONCLUSIONS
  These findings suggest that decreased CAIx associated with aerobic exercise reflects the change in cerebral haemodynamics resulting from dietary nitrate supplementation. Future studies should determine whether the BJ-induced decrement in CAIx is correlated with an improvement in brain function.
authors.affiliation: Professor, Department of Medicine, Division of Cardiology, Howard University College of Medicine and Howard University Hospital , Washington, DC 20060, United States of America .
authors.forename: Bryan Heath
authors.initials: BH
authors.lastname: Curry
authors.affiliation: Professor, Department of Recreation, Human Performance and Leisure Studies and Exercise Science and Human Nutrition Laboratory, Howard University Cancer Centre , Washington, DC 20060, United States of America .
authors.forename: Vernon
authors.initials: V
authors.lastname: Bond
authors.affiliation: Associate Professor, Department of Medical Pharmacology, AUA College of Medicine and Manipal University , Antigua .
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Pemminati
authors.affiliation: Assistant Professor, Department of Behavioural Sciences and Neuroscience, AUA College of Medicine , Antigua .
authors.forename: Vasavi Rakesh
authors.initials: VR
authors.lastname: Gorantla
authors.affiliation: Instructor, Department of Clinical Medicine, AUA College of Medicine , Antigua .
authors.forename: Yulia Andreevna
authors.initials: YA
authors.lastname: Volkova
authors.affiliation: Assistant Professor, Department of Medical Physiology, AUA College of Medicine , Antigua .
authors.forename: Kishan
authors.initials: K
authors.lastname: Kadur
authors.affiliation: Professor, Department of Medical Physiology, AUA College of Medicine , Antigua .
authors.forename: Richard Mark
authors.initials: RM
authors.lastname: Millis
keywords: Aerobic exercise; Blood pressure; Nitric oxide