Effect of Beetroot Juice on Cardiovascular and Autonomic Responses to Exercise in Adults With Type 2 Diabetes

Summary

This study will investigate whether a single dose of beetroot juice can improve cardiovascular responses and recovery after exercise in adults with Type 2 Diabetes.

Type 2 Diabetes is associated with higher blood pressure, impaired blood vessel function, and reduced autonomic control of the heart, all of which increase cardiovascular risk and may affect how the body responds to and recovers from physical activity. Beetroot juice is naturally rich in dietary nitrate, which is converted in the body into nitric oxide, a molecule that helps blood vessels relax and improve blood flow. While these effects have been demonstrated in healthy individuals, less is known about their impact in people with Type 2 Diabetes.

In this study, approximately 16 to 20 adults aged 40 to 65 years with Type 2 Diabetes will take part. After an online screening and consent process, eligible participants will attend two laboratory visits at Oxford Brookes University. In a randomised, double-blind, placebo-controlled crossover design, participants will receive beetroot juice during one visit and a nitrate-depleted placebo during the other visit.

During each visit, participants will undergo physiological measurements, including blood pressure, heart rate, oxygen saturation, and capillary blood glucose. Participants will then complete a short session of supervised, light-to-moderate cycling exercise. Measurements will continue during the recovery period to assess how quickly the cardiovascular system returns to resting levels.

The main outcomes are systolic blood pressure and heart rate variability during recovery, which reflect cardiovascular regulation and autonomic function. Secondary outcomes include diastolic blood pressure, heart rate, blood glucose, and markers related to nitric oxide availability.

This study may help determine whether a simple, dietary-based intervention such as beetroot juice can support cardiovascular function and improve recovery after exercise in people living with Type 2 Diabetes.

Conditions

• Type 2 Diabetes Mellitus
• Hypertension
• Autonomic Nervous System Diseases

Interventions

DIETARY_SUPPLEMENT

Beetroot juice

A single dose of approximately 70 mL of nitrate-rich beetroot juice providing approximately 400 mg of inorganic nitrate will be administered. The product consists of concentrated beetroot juice with a small amount of lemon juice and is consumed prior to exercise testing. The timing of ingestion is standardized to allow peak nitrate-nitrite-nitric oxide conversion within approximately 2 to 3 hours. This intervention is intended to increase nitric oxide bioavailability and assess its acute effects on cardiovascular and autonomic responses.

DIETARY_SUPPLEMENT

Nitrate-depleted Beetroot Juice Placebo

A nitrate-depleted beetroot juice placebo matched for appearance, taste and packaging will be administered in a single dose of approximately 70 mL. The placebo is identical to the active intervention in all aspects except for nitrate content. It is consumed under the same standardized conditions and timing as the active intervention to maintain blinding and allow controlled comparison of physiological responses.

Sponsors & Collaborators

• Oxford Brookes University

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Model

CROSSOVER

Eligibility

Min Age

40 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-04-02

Primary Completion

2026-07-31

Completion

2026-07-31

Countries

• United Kingdom

Study Locations