Dietary Nitrate Supplements and Ischemic Stroke Recovery

Overview

This is a double-blind, randomized, placebo-controlled, pilot study. Participants will be randomized to receive either beetroot juice or a beetroot juice placebo, as a dietary supplement, for 30 days. Beetroot juice is high in nitrates, a chemical when ingested is found to increase blood flow to the brain. The purpose of this research study is to determine the safety and feasibility of using this nutritional intervention in (ischemic)stroke survivors, and prove that plasma levels of nitrate and nitrite increase as expected. Secondary outcomes includes measuring a comprehensive set of outcomes related to functional status post-stroke, including mobility, upper extremity strength, cognition, depression, and disability. Patients will also be randomized to MRI perfusion scanning in the region of the stroke to measure cerebral blood flow.

In this proof of concept study, the investigators will for the first time, determine whether dietary nitrate (commercially available beetroot juice) is safe and feasible to administer in ischemic stroke patients, and whether its use is associated with increased plasma nitrate and nitrite levels and trends toward improvement during the standard 30-day rehabilitation period after a stroke. The investigators will test the hypotheses using a double-blinded randomized placebo-controlled trial of Beet It® shots once daily for 30 days for patients enrolled within 5 days of stroke onset. This novel study will provide key safety and feasibility data on dietary nitrate supplementation and preliminary information on the magnitude of its effect on improving mobility and functional status, cognition and cerebral blood flow. These data are needed to accelerate the pace of development of this novel therapeutic strategy: using a non-pharmacological approach for improving stroke outcomes. The specific aims are to: Aim 1) Test the proof of concept that beetroot juice consumption is feasible and safe in ischemic stroke patients when given during the post-acute rehabilitation period. Primary outcomes are adherence to the intervention, measurement of outcomes and follow-up (feasibility), as well as adverse events (safety), reported as proportions in each group and across the entire study cohort. Hypothesis: Beetroot juice is safe and feasible in this population, and leads to increased plasma nitrate and nitrite levels at 30 days. Secondary outcomes of interest include change in gait speed (m/sec), Modified Rankin score (disability scale), NIHSS, EuroQOL-5D (quality of life),Patient Health Questionnaire-9 (depression), Stroke Impact Scale-16 (SIS-16), Barthel Index, Short Physical Performance Battery, grip strength and the Montreal Cognitive Assessment (MoCA). Aim 2) Determine whether beetroot juice consumption increases cerebral blood flow vs. placebo juice. Cerebral blood flow will be determined from MRI collected 2 hours following ingestion of the beetroot juice on day 30. Anatomic and perfusion imaging (PASL) will be performed. A region of interest will be used to measure blood flow in a 20mm sphere placed adjacent to the ischemic stroke and in the contralateral hemisphere. Hypothesis: Ischemic stroke patients randomized to the beetroot juice intervention will show increased cerebral blood flow as measured by MRI perfusion scanning in the region of the stroke compared with the placebo group at 30 days.