Effects of Dietary Nitrate From Vegetable/Fruit Juice on Cerebral Blood Flow Parameters

Northumbria University40 enrolled

Overview

Nitrate provides the body with an alternative source of Nitric Oxide which plays a large role in promoting blood flow and reducing blood pressure. Nitrate supplementation with vegetable/fruit juice has recently been shown to reduce blood pressure and reduce energy expenditure during low intensity exercise. Such findings combined with the previously known biological effects of nitric oxide would suggest that nitrate supplementation would also impact on blood flow. The aim of this study is to examine the effects of dietary nitrate supplementation via vegetable/fruit juice drink on cerebral (brain) blood flow (using Near Infrared Spectroscopy).

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Enrollment

Conditions

Cerebrovascular Circulation Cognitive Impairment

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 35 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * healthy young (18-35 years) male and female adults, not vulnerable. Exclusion Criteria: * smoke or consume any tobacco products (even occasionally) * not proficient in English * pregnant (or are seeking to become) * currently taking recreational, over the counter/prescription medication (excluding the contraceptive pill), and/or dietary/herbal supplements. * any food allergies or sensitivities that are relevant to the study * history of/current head trauma, learning difficulties, ADHD, dyslexia, migraines or any gastric problems.

Outcomes

Primary Outcomes

Change from baseline cerebral blood flow

Near infrared spectroscopy monitoring of cerebral blood flow in the frontal cortex during demanding tasks. Monitored from baseline, through 90 minutes of drink absorption and 60 minutes of cognitive task performance.

Time frame: From baseline to 2.5 hours post-dose

Change from baseline cognitive function

Performance of the cognitive demand battery (CDB), which assesses aspects of psychomotor speed, working memory and executive function. The CDB involves 6 repetitions of the following tasks: serial three subtractions (2 mins); serial seven subtractions (2 mins); Rapid Visual Information Processing (5 mins) and a subjective rating of mental fatigue

Time frame: 90 minutes post-dose

Change from baseline mood

Bond-Lader visual analogue mood scales assessing the mood factors 'alert'; 'calm'; and 'content'

Time frame: 2.5 hours post-dose

Secondary Outcomes

Change from baseline blood pressure, heart rate and venous nitrate and nitrite levels

Diastolic and systolic blood pressure and heart rate monitored after completion of cognitive tasks to assess peripheral blood flow effects. Plasma nitrate and nitrite levels assessed at 2.5 hours post-dose.