Role of Flavanols in Exercise and Aging

Not Applicable

Completed

• Conditions: Aging
• Interventions: Dietary Supplement: High Flavanol Trial; Dietary Supplement: Low Flavanol Trial; Dietary Supplement: High Flavanol Trial; long-term; Dietary Supplement: Low Flavanol Trial; long-term effects

• Registration Number: NCT01557738
• Lead Sponsor: University of Texas at Austin

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2012-03-08
• Study First Submitted QC: 2012-03-15
• Study First Posted: 2012-03-19
• Study Start: 2012-12
• Primary Completion: 2014-04
• Study Completion: 2014-04
• Status Verified: 2014-05
• Last Update Submitted: 2014-06-24
• Last Update Posted: 2014-06-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 20

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Acute effects of flavanol consumption	High Flavanol Trial	The 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	Low Flavanol Trial	Once 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	High Flavanol Trial; long-term	Only 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	Low Flavanol Trial; long-term effects	Only 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.

Primary Outcome Measures

Name	Time	Method
Change in femoral blood flow during exercise following flavanol consumption	During knee extension exercise, change from baseline in blood flow 2 hours post flavanol ingestion	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.

Secondary Outcome Measures

Name	Time	Method
Change in flow-mediated dilation (FMD) following flavanol consumption	Change from baseline in FMD 2 hours post flavanol ingestion	Flow-mediated dilation is commonly used as an index of nitric oxide bioavailability. Nitric oxide is believed to play a role in blood flow regulation during exercise. A baseline value will be obtained and then the measurement will be performed again 2 hours after flavanol ingestion.

Trial Locations

Locations (1)

University of Texas at Austin: Environmental and Autonomic Physiology Laboratory; 🇺🇸 Austin, Texas, United States