Effects of beetroot juice and folate supplementation on blood pressure

INTERVENTION:

The study is divided in four phases: selection of participants, screening, baseline/randomisation and intervention. Participants will be randomised into 3 groups using an online platform (sealed‐envelopes.com). A member of staff not involved in the study will be the custodian of the randomisation list and he/she will be responsible for the provision to the study participants of the nutritional interventions so as not to compromise the double‐blinding of the trial. Group 1 and Group 2 will be provided with a nutritional interventional, whereas Group 3 will be the control group. Participants in Group 1 will be asked to consume a small bottle (70 ml) of concentrated beetroot juice (Beet it shots, James White LTD, UK), which is naturally enriched in inorganic nitrate (approximately 400 mg of inorganic nitrate). Participants will be asked to drink the beetroot juice in the morning and will be provided with a form to record the time of the consumption and if they experience any problems. Participants will be considered not compliant to the intervention if they miss 7 or more supplementation days. Participants will be asked not to change their habitual dietary habits, physical activity level and alcohol and caffeinated drinks consumption during the trial. Participants will be provided with the specific amount of beetroot juice to be consumed during the intervention period. Participants in Group 1 will also be asked to take one folate capsule (5 mg folate) every morning after consumption of the beetroot juice, and will be provided with a form to record the time of consumption and if they experience any problems. Participants will be considered not compliant with the intervention if they miss seven or more supplementation days. Participants will be provided with the specific amount of capsules to be consumed during the intervention period. Capsules will be dispensed in plastic containers showing

CONDITION:

Hypertension ; Circulatory System ; Hypertension (high blood pressure)

PRIMARY OUTCOME:

Compliance to the intervention, assessed using self‐developed standardised feedback questionnaires at the baseline, 30 days and 60 days (end of the study).

INCLUSION CRITERIA:

1. Aged 50‐70 years old 2. Non‐smokers 3. Drug naïve 4. Hypertension (stage 1, systolic blood pressure 130‐170 mmHg) 5. BMI 18‐40 kg/m²

SECONDARY OUTCOME:

; 1. Changes in resting and 24 hour ambulatory blood pressure (BP):; 1.1. Resting blood pressure assessed using an automated BP monitor at the baseline, after 1 month and at the end of the study; 1.2. 24 hour ambulatory blood pressure assessed using a BP monitor with an inflatable cuff secured around the arm, which will regularly inflate and deflate over the 24 hour period; 2. Changes in whole‐body nitric oxide (NO) production, assessed using the Oral Nitrate Test (non‐invasive stable isotope method) at the baseline and after 60 days (end of the study); 3. Blood nitrate concentration, assessed using the ONT method, with samples then being derivatised using the nitromesitylene method and the enrichment level of the tracer will be determined using gas chromatography/mass spectrometry at the baseline and after 60 days (end of the study); 4. Blood folate concentration, assessed using the ONT method, with samples then being derivatised using the nitromesitylene method and the enrichment level of the tracer will be determined using gas chromatography/mass spectrometry at the baseline and after 60 days (end of the study); 5. Validity of Berkeley Life Nitric Oxide Saliva Test Strips for the assessment of nitrite concentrations, assessed at the baseline and after 30 and 60 days;