Effect of Beetroot Juice on Blood Pressure Regulation in Post Menopausal Women

Acute Blood Pressure-lowering Effects of Beetroot Juice in Postmenopausal Women With and Without Hypertension

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.

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.

Inclusion Criteria:

• Resting systolic blood pressure less than or equal to 160 mmHg
• Resting diastolic blood pressure less than or equal to 100 mmHg

Exclusion Criteria:

• Overt cardiovascular, metabolic, hematologic, pulmonary, renal, musculoskeletal, and/or neurological disease(s)

• Users of any tobacco and/or nicotine products (smokers, chewing tobacco, nicotine-containing patches/gum, smokeless cigarettes)

• Body mass index greater than 35

• Total cholesterol greater than 239 mg/dl

• LDL cholesterol greater than 159 mg/dl

• Fasting blood triglycerides greater than 199 mg/dl

• Fasting blood glucose greater than 109 mg/dl and HbA1c greater than 6.0%

• Individuals currently taking any of the following medications:

  1. blood pressure lowering medication (e.g., beta blockers, ACE inhibitors, angiotensin antagonists, calcium channel blockers, diuretics)
  2. lipid-lowering medication (e.g., statins)
  3. nitrates (e.g. nitroglycerin) for angina
  4. phosphodiesterase inhibitors (e.g., Viagra)
  5. anti-inflammatory drugs

• Individuals currently taking hormone replacement therapy