Role of Flavanols in Exercise and Aging
Acute and Long-term Effects of Dietary Flavanols on Local Control of Skeletal Muscle Blood Flow During Exercise in Young and Old Humans
1 other identifier
interventional
20
1 country
1
Brief Summary
It has well known that diets rich in fruits, vegetables and cocoa products are associated with positive health benefits and these positive effects have been shown to be due to compounds they contain called flavanols. Flavanols have been shown to exert their positive effects by indirectly increasing nitric oxide (NO) bioavailability. NO is a potent vasodilator that is believed to play a role in increasing blood flow to active muscle during exercise. This regulatory process is impaired with healthy aging. The underlying premise to this study is that if NO bioavailability can be increased following flavanol ingestion, will there be a restoration of blood flow during exercise in older individuals? Accordingly, the first part of this research project will compare the acute vascular effects of flavanol ingestion between a young and old group. The investigators have hypothesized that both groups will show an improvement in blood flow to active muscle during exercise, though the magnitude of the change will be greater in the older group. The second part of this project will look at the effects of 4 weeks of daily flavanol ingestion in the old group. The investigators hypothesize that subjects will demonstrate an improvement in blood flow to active muscle during exercise after the 4 week intervention and that the magnitude of the change will be greater than the acute effects. Findings from this proposal will provide evidence for the efficacy of flavanols to be used (as a simple and safe lifestyle intervention) to reverse or combat impaired blood flow regulation in older individuals.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at below P25 for not_applicable
Started Dec 2012
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
March 8, 2012
CompletedFirst Posted
Study publicly available on registry
March 19, 2012
CompletedStudy Start
First participant enrolled
December 1, 2012
CompletedPrimary Completion
Last participant's last visit for primary outcome
April 1, 2014
CompletedStudy Completion
Last participant's last visit for all outcomes
April 1, 2014
CompletedJune 25, 2014
May 1, 2014
1.3 years
March 8, 2012
June 24, 2014
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Change in femoral blood flow during exercise following flavanol consumption
Blood flow regulation to active muscles during knee extension exercise can be assessed by using ultrasound to measure blood flow in the femoral artery. This will be done before and after stimulation of the sympathetic nervous system. A baseline value will be obtained and then the measurement will be performed again 2 hours after flavanol ingestion.
During knee extension exercise, change from baseline in blood flow 2 hours post flavanol ingestion
Secondary Outcomes (1)
Change in flow-mediated dilation (FMD) following flavanol consumption
Change from baseline in FMD 2 hours post flavanol ingestion
Study Arms (4)
Acute effects of flavanol consumption
EXPERIMENTALThe outcome measurements will be made on all study participants before and 2 hours after consumption of the high flavanol beverage.
Low Flavanol Trial; acute effects
PLACEBO COMPARATOROnce again, the outcome measurements will be made on all study participants before and 2 hours after consumption of the low flavanol beverage.
Long-term effects of flavanol consumption
EXPERIMENTALOnly those study participants over 60 years of age will continue with this arm of the trial. The same outcome measures will be performed following 4 weeks of daily consumption of a high flavanol beverage.
Low Flavanol Trial; long-term effects
PLACEBO COMPARATOROnly those study participants over 60 years of age will continue with this arm of the trial. The same outcome measures will be performed following 4 weeks of daily consumption of a low flavanol beverage.
Interventions
The experimental trial (high flavanol content) will involve the consumption of a beverage containing about 1000mg of cocoa flavanols.
The placebo trial (low flavanol content) will involve the consumption of a beverage containing 75 mg of cocoa flavanols.
The experimental trial (high flavanol content) will involve the daily consumption of a beverage containing about 1000mg of cocoa flavanols for 4 weeks. Subjects will be provided with 28 packets of the beverage to take home with them.
The placebo trial (low flavanol content) will involve the daily consumption of a beverage containing 75 mg of cocoa flavanols for 4 weeks. Subjects will be provided with 28 packets to take home with them.
Eligibility Criteria
You may qualify if:
- Males and Females between 18 - 30 years old
- Males and Females between 60 - 80 years old
You may not qualify if:
- cardiovascular and/or microvascular disease
- blood clotting disorder
- pregnant lady
- current smoker (or regularly smoked within last year)
- a history of an adverse reaction to cold
- taking medications known to effect the autonomic nervous system
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
University of Texas at Austin: Environmental and Autonomic Physiology Laboratory
Austin, Texas, 78712, United States
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Michelle Harrison, M.A.
University of Texas at Austin
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- DOUBLE
- Who Masked
- PARTICIPANT, INVESTIGATOR
- Purpose
- BASIC SCIENCE
- Intervention Model
- CROSSOVER
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Assistant Professor
Study Record Dates
First Submitted
March 8, 2012
First Posted
March 19, 2012
Study Start
December 1, 2012
Primary Completion
April 1, 2014
Study Completion
April 1, 2014
Last Updated
June 25, 2014
Record last verified: 2014-05