Clinical trial NCT01557738: Role of Flavanols in Exercise and Aging
Official title: Acute and Long-term Effects of Dietary Flavanols on Local Control of Skeletal Muscle Blood Flow During Exercise in Young and Old Humans
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Aging
Keywords: Exercise
Blood Flow
Nitric Oxide
Aging
Antioxidant
Flavanol
Young (18-30 yrs)
Aging (60 - 80 yrs)
Lead sponsor: University of Texas at Austin
Sponsor class: OTHER
First posted: 2012-03-19
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

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.


Eligibility criteria: Inclusion Criteria:

* Males and Females between 18 - 30 years old
* Males and Females between 60 - 80 years old

Exclusion Criteria:

* 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

Primary outcomes:
measure: Change in femoral blood flow during exercise following flavanol consumption
timeFrame: During knee extension exercise, change from baseline in blood flow 2 hours post flavanol ingestion
Secondary outcomes:
measure: Change in flow-mediated dilation (FMD) following flavanol consumption
timeFrame: Change from baseline in FMD 2 hours post flavanol ingestion
Other outcomes:
Locations:
city: Austin
country: United States
facility: University of Texas at Austin: Environmental and Autonomic Physiology Laboratory
state: Texas
Study officials:
affiliation: University of Texas at Austin
name: Michelle Harrison, M.A.
role: PRINCIPAL_INVESTIGATOR
References: