Effects of Dietary Nitrate and Vitamin C Co-supplementation on Blood Pressure and Endothelial Function in Overweight Individuals

Inclusion Criteria: * Participant is willing and able to give informed consent for participation in the study. * Participant is willing and able to comply with the requirements of the study protocol. * Non-smoking men and women. * Aged between 50-75 years. * Overweight and obese (BMI: over 25.0 kg/m2). Exclusion Criteria: * Having taken part in a research study in the last 3 months involving invasive procedures or an inconvenience allowance. * Vegetarian. * Smoking. * Resting systolic blood pressure greater than 160 mmHg; diastolic blood pressure greater than 100 mmHg. * Active cancer and any diagnosis of malignant cancer in the last 5 years. * Excessive alcohol intake (\>21 units per week). * Allergy or intolerance to the intervention food (Beetroot juice). * Diagnosis of chronic or acute metabolic and inflammatory conditions that may interfere with the study outcomes. * Major surgical operations. * Use of prescribed psychiatric drugs (antidepressants, sedatives, antipsychotics), diuretics, organic nitrates, statins and proton pump inhibitors. * Use of prescribed hormonal therapies (oestrogens, thyroxin, and progesterone), anti-hypertensive (Calcium++ channel blockers, beta-blockers, and angiotensin-converting-enzyme (ACE) inhibitors), only if the prescription had started, or the dose had been started/changed, in the previous three months. * Non-prescribed dietary supplements if not stopped at least for 2 weeks before starting the trial. * Use of the mouthwash during the study was not allowed as it interferes with the conversion of oral nitrate into nitrite.