Conditions: Postmenopausal Women
Keywords: Dietary nitrate supplementation Beetroot juice
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 16
Healthy volunteers: yes

Brief summary:
In this study the investigators will test the hypothesis that acute consumption of inorganic nitrate (supplied in concentrated beetroot juice) reduces artery stiffness and resting blood pressure, and lessens the rise in blood pressure during handgrip exercise in postmenopausal women. Understanding and improving artery function and blood pressure regulation in women is important because they undergo accelerated arterial stiffening after menopause and have much larger increases in blood pressure when they exercise compared with either premenopausal women or men of similar age.

Detailed description:
Postmenopausal women have stiff central arteries and exaggerated blood pressure (BP) responses during exercise compared with either premenopausal women or men of similar age. Arterial stiffness and exaggerated BP responses to exercise are prognostic for heart wall thickening, future hypertension, adverse cardiovascular events, and mortality. Previous studies have reported that acute consumption of nitrate-rich beetroot juice can lower resting and exercising BP responses in older adults. However, these studies included both sexes and did not compare the effects of beetroot juice to a nitrate-depleted placebo (a true control). Thus, the potential BP lowering effects of nitrate supplementation per se have not been established in postmenopausal women. The present study examines the acute (single dose) effects of nitrate-rich beetroot juice on resting hemodynamics (peripheral and central BP, arterial wave properties, etc), and physiological responses to handgrip exercise in metabolically healthy post-menopausal women.

Arms:
arm 1: Subjects will consume 140 ml of beetroot juice (Beet-It Organic Shot) approximately 90 min before physiological testing. arm 2: Subjects will consume 140 ml of beetroot juice (Beet-It Organic Placebo) approximately 90 min before physiological testing.

Interventions: intervention 1: Beetroot juice intervention 2: Beetroot juice placebo
Intervention descriptions: intervention 1: This beverage contains 0.3 g of inorganic nitrate per 70 ml container, and is bottled and supplied by James White Drinks (UK). intervention 2: This beverage is identical in look and taste to the Beet-It organic shot, but has the nitrate removed. It is also bottled and supplied by James White Drinks (UK).

Protocol document:
Prot_SAP_000.pdf: 





















































ICF_001.pdf: