Nitrate, Exercise and Vascular Function in Midlife Women
Effects of Dietary Nitrate From Beetroot Juice on Vascular Function and Adaptations to Exercise Training in Postmenopausal Women: a Randomized, Placebo-controlled Study
University of Vienna
54 participants
Mar 31, 2025
INTERVENTIONAL
Conditions
Summary
The purpose of this clinical study in women after menopause is to investigate whether the daily intake of nitrate from beetroot juice over 12 weeks enhances the positive effect of exercise training on vascular function, blood pressure and physical performance. The risk of cardiovascular diseases (CVD) increases with advancing age and women are particularly affected. In women, the decline in the sex hormone oestrogen in the blood circulation with menopause contributes to impaired vascular function and an increased CVD risk; in part through increased inflammatory processes, oxidative stress, and a reduced body's own production of nitric oxide (NO). NO is a signaling molecule that is important for vascular function. Endurance-based exercise training is a key lifestyle strategy to prevent CVD. However, studies indicate that exercise is less effective in terms of its health-promoting adaptations in women after menopause as compared with men of similar age. This study investigates the effect of exercise training in combination with the intake of nitrate-rich beetroot juice on functions of the cardiovascular system. Nitrate is a nitrogen compound that is found naturally in plant foods (e.g. beetroot juice) and is converted to NO in the human body. Results of previous studies indicate vasodilatory, blood pressure-lowering and performance-enhancing effects as well as positive influences on inflammatory processes and oxidative stress following nitrate intake. The hypothesis is that nitrate intake concomitant to training promotes training adaptations and further improves vascular function, blood pressure and physical performance compared to training without nitrate intake. For the study, 54 untrained postmenopausal women (with the ages between 45 and 65 years) will be recruited and randomly allocated into two groups. Both groups will undergo 12 weeks of endurance-based exercise training. One group will receive nitrate-rich beetroot juice, and the other nitrate-depleted beetroot juice (as placebo). Vascular function, blood pressure, maximum oxygen uptake, and blood biomarkers for nitrate metabolism, inflammation status and oxidative stress will be examined. The anticipated study results will provide new insights into whether nitrate as a 'training adjunct' improves health-promoting training adaptations in women after menopause. The overall aim is to improve the cardiovascular health and performance of middle-aged women and reduce their increased CVD risk.
Eligibility
Inclusion Criteria2
- Postmenopausal women (amenorrhoeic ≥1 year), between the ages of 45 and 65 years, inclusive, who are either normotensive or are medically treated for stage 1 hypertension
- Written informed consent
Exclusion Criteria19
- Current or recent (within previous 3 months) engagement in exercise training (i.e., planned, structured, and regular exercise) with an average net exercise time of >2 hours per week
- Above-average cardiorespiratory fitness levels (i.e., a V̇O2 max max above the 75th percentile of age- and sex-specific normative data: ≥43 mL/kg/min for women aged 45-49 years, ≥38 mL/kg/min for women aged 50-59 years, ≥35 mL/kg/min for women aged 60-65 years)
- Any evidence of acute or chronic diseases such as symptomatic cardiovascular or peripheral vascular disease, moderate or severe chronic kidney disease (estimated glomerular filtration rate (GFR) <50 mL/min), pulmonary, neural, or musculoskeletal disease, osteoporotic fractures, cancer, or type 1 or 2 diabetes mellitus
- Fasting glucose >7.0 mmol/L or HbA1c > 6.5 rel. %
- BMI <18.5 kg/m2 or >30kg/m2
- A mean 24-hour ambulatory systolic/diastolic blood pressure of ≥130/80 mm Hg
- Irregular resting electrocardiography (ECG)
- Inability to perform physical exercise
- Abnormal cardiovascular responses during the baseline V ̇O2 max test, including symptoms, ECG abnormalities, arrhythmias, or exaggerated blood pressure responses
- Current or recent (<12 months) oestrogen-based hormone-replacement therapy
- Chronic use of nitric oxide (NO) donors, organic nitrites/nitrates, Ticagrelor, sodium-glucose cotransporter 2 (SGLT2) inhibitors, high-dose statins (i.e., Simvastatin >40mg/day, Atorvastatin >20mg/day, Rosuvastatin >10mg/day), acetylsalicylic acid >100mg/day, non-steroidal anti-inflammatory drugs (NSAID)
- A change in drug therapy likely to influence major outcomes within the previous 2 months, or likelihood that drug therapy would change during the study
- Use of antibiotics (within previous 2 months)
- Use of antibacterial mouthwash (volunteers willing to cease using antibacterial mouthwash for a period of 4 weeks before randomization will be included)
- Being vegan or vegetarian or consumption of >5 serves of vegetables per day
- Current or recent (within previous 6 months) significant (>6%) loss or gain of body weight
- Current or recent (<12 months) regular smoking of >5 cigarettes per day
- Alcohol intake of >70 g per week and/or binge drinking behaviour
- Inability or unwillingness to follow the study protocol
Interested in this trial?
Get notified about updates and connect with the research team.
Interventions
Daily consumption of 70 mL beetroot juice containing \~400 mg nitrate over an intervention period of 12 weeks concomitant to exercise training, either 3 hours pre-exercise on training days or with breakfast on non-training days.
Daily consumption of 70 mL nitrate-depleted beetroot juice (placebo) over an intervention period of 12 weeks concomitant to exercise training, either 3 hours pre-exercise on training days or with breakfast on non-training days.
Locations(1)
View Full Details on ClinicalTrials.gov
For the most up-to-date information, visit the official listing.
NCT06527248