NO3-rich Beet Juice and Exercise on Postmenopausal Women Cardiovascular Health

Nitrate-rich Beet Juice Intake and Aerobic Exercise on Cardiovascular Health of Postmenopausal Women With Arterial Hypertension

In the context of physical exercise, there is no evidence of the acute and continued use of beetroot juice with a previously recommended dose of nitrate (NO3) (>300mg) on the cardiovascular performance of hypertensive and postmenopausal women. We will investigate the effects of beetroot juice rich in NO3 acutely (first day: 140mL/800mg) and during a week with daily doses (second to the seventh day: 70mL/400mg) on blood pressure, heart rate (HR), cardiac autonomic control, EF, inflammatory, hormonal, and stress biomarkers oxidative stress and enzymes involved in nitric oxide synthesis and mitochondrial regulation, under resting conditions, as well as mediated by submaximal aerobic exercise sessions. Through a randomized, crossover, triple-blind, placebo-controlled clinical trial, 20 physically inactive hypertensive women will undergo an acute and 7-day trial, each with two intervention protocols: 1) placebo and 2) beetroot; in which will ingest beet juice with or without NO3 in its composition with a 7-day washout interval. On collection days, exercise will be performed on a treadmill for 40 minutes at a speed corresponding to 65-70% of VO2peak. The collection of variables (cardiovascular, autonomic, and blood samples for molecular analyses) of the study will take place at rest (120 minutes after ingestion of the intervention), during exercise (40 minutes), and in the effort recovery stage (during 65 minutes) based on previously validated protocols. The collections were arranged so that the measurement of one variable does not interfere with the other and that they have adequate intervals between them.

Acute intervention: 1st day [140 ml - Beet It Juice, 800mg nitrate/day] Continued intervention: 2nd to 7th day [70 ml - Beet It Juice, 400mg nitrate/day] Exercise intervention [Treadmill - 40 minutes duration, 65% - 70% VO2 Peak]: Acute [Just on day] / Continued [First and latest day] Washout: 7 days

Acute intervention (1st day): [140 ml - Beet It Juice, 0mg nitrate/day] Continued intervention (2nd to 7th day): [70 ml - Beet It Juice, 0mg nitrate/day] Exercise intervention [Treadmill - 40 minutes duration, 65% - 70% VO2 Peak]: Acute [Just on day] / Continued [First and latest day] Washout: 7 days

On the first day, an acute test will be carried out with beet juice rich in nitrate, in which two units of juice will be provided, totaling 140 ml (800 mg of nitrate) for each protocol. That is, each participant will receive 2 units of juice bottles. From the second to the seventh day, participants will receive 6 units of vials of the juice corresponding to the first intervention on the first visit to the laboratory and will drink one vial a day for a week. Of the 8 units (100%), six bottles (75%) will be provided for the participants to take home. On the seventh day of the intervention, the participants will return to the laboratory for the consumption of the seventh and last bottle of juice. Between one protocol and another, a 7-day washout interval will be given for the purification of the compounds provided by the protocols.

Inclusion Criteria: Women with 50 to 65 old years; Physically inactive; Postmenopausal diagnosis (amenorrhea for 12 months or more); Arterial hypertension diagnosis (previously); Systolic blood pressure values >120mmHg up to 159mmHg and diastolic blood pressure values >80mmHg up to 99mmHg. Exclusion Criteria: Previous history of acute myocardial infarction and/or stroke; Allergy or intolerance to nitrate, gluten, or milk; Medications (proton pump inhibitors, beta-blockers, calcium channels antagonists).