Aging
Conditions
Brief summary
Vascular and skeletal muscle function decline with age and are associated with decreased nitric oxide (NO) bioavailability. Dietary nitrate supplementation in the form of beet root juice increases NO bioavailability and improves exercise tolerance in younger adults, yet its effects on fatigability in older adults are largely unknown. The proposed research will investigate the impact of increased NO bioavailability on vascular function, skeletal muscle bioenergetics, and fatigability in older (≥65 yrs) men and women.
Interventions
DIETARY_SUPPLEMENTBeetroot Juice
7 days of 140 mL per day of beetroot juice
7 days of 140 mL per day of placebo beetroot juice
Sponsors
Marquette University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
60 Years to 90 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy men and women ≥ 60 years old
Exclusion criteria
1. body mass index ≥40 kg/m2; 2. type 1 or type 2 diabetes or HbA1c \>6.5% 3. uncontrolled hypertension; 4. active cancer, cancer in remission, or having received treatment for any form of cancer in the previous five years; 5. coronary artery disease; 6. cardiovascular disease (e.g., PAD, PVD); 7. abnormal and untreated thyroid function; 8. chronic and/or regular nonsteroidal anti-inflammatory drugs (NSAID) consumption, 9. tobacco use (includes smoking); 10. any condition that presents a limitation to exercise (e.g., severe arthritis, COPD, neuromuscular disorder, moderate or severe cognitive impairment, Alzheimer's Disease, severe untreated sleep apnea).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in fatigability of the knee extensor muscles with beetroot juice supplementation | Day 8 (after 7 days of placebo supplementation) and day 29 (after 14 days of a washout period with no supplementation plus 7 days of beetroot juice supplementation) | Fatigability will be quantified as the reduction in limb muscle power output during a 4-minute dynamic fatiguing exercise task using a dynamometer. Fatigability after 7 days of beetroot juice supplementation will be compared with fatigability after 7 days of placebo supplementation, with the outcome measure being the change (or difference) between these two supplementation conditions. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in femoral artery blood flow with beetroot juice supplementation | Day 8 (after 7 days of placebo supplementation) and day 29 (after 14 days of a washout period with no supplementation plus 7 days of beetroot juice supplementation) | Femoral artery blood flow will be quantified as the change in femoral artery blood flow during a 4-minute dynamic fatiguing exercise task using a ultrasonography. Femoral artery blood flow after 7 days of beetroot juice supplementation will be compared with Femoral artery blood flow after 7 days of placebo supplementation, with the outcome measure being the change (or difference) between these two supplementation conditions. |
| Change in muscle efficiency with beetroot juice supplementation | Day 8 (after 7 days of placebo supplementation) and day 29 (after 14 days of a washout period with no supplementation plus 7 days of beetroot juice supplementation) | Muscle efficiency will be quantified as the ATP cost of contraction using phosphorus magnetic resonance spectroscopy (P-MRS). Muscle efficiency after 7 days of beetroot juice supplementation will be compared with muscle efficiency after 7 days of placebo supplementation, with the outcome measure being the change (or difference) between these two supplementation conditions. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Change in plasma nitrate concentration with beetroot juice supplementation | Day 8 (after 7 days of placebo supplementation) and day 29 (after 14 days of a washout period with no supplementation plus 7 days of beetroot juice supplementation) | Plasma nitrate concentration will be quantified using a nitrate colorimetric assay. Plasma nitrate concentration after 7 days of beetroot juice supplementation will be compared with plasma nitrate concentration after 7 days of placebo supplementation, with the outcome measure being the change (or difference) between these two supplementation conditions. |
| Change in plasma nitrite concentration with beetroot juice supplementation | Day 8 (after 7 days of placebo supplementation) and day 29 (after 14 days of a washout period with no supplementation plus 7 days of beetroot juice supplementation) | Plasma nitrite concentration will be quantified using a nitrite colorimetric assay. Plasma nitrite concentration after 7 days of beetroot juice supplementation will be compared with plasma nitrite concentration after 7 days of placebo supplementation, with the outcome measure being the change (or difference) between these two supplementation conditions. |
Countries
United States
Contacts
Primary ContactTimothy Fulton, PhD
Outcome results
None listed