Role of Flavanols in Exercise and Aging

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.