Influence of High Polyphenol Beverage on Stress-Induced Platelet Activation.
Platelets are playing a crucial role in acute cardiovascular events. We investigated if physical stress activates platelets and whether this activation can be inhibited by a polyphenol-enriched diet.



Blood samples were taken from a total of 103 athletes three weeks before, one day before, immediately as well as 24 hours and 72 hours after a marathon run. Participants were randomized, double-blinded and divided into two groups. One group received a polyphenol-rich beverage the other the same beverage without polyphenols. Besides analysis of platelet counts and impedance-aggregometric-measurement of platelet activity, soluble P-selectin and Endothelin-A measurements were performed.



In the control group, runners showed a 2.2-fold increased platelet aggregation directly after completing a marathon and within the following three days when compared with baseline values (p<0.01). In accordance, significant increases in sP-selectin (57.52ng/ml vs. 94.86ng/ml;p<0.01) were detectable. In contrast, for the group consuming a beverage with increased polyphenol content (upper quartile of study beverage intake) we did not find any increase of platelet aggregation.



Physical stress causes a significant increase in platelet activity. Our results demonstrate that a diet enriched in polyphenols is capable of preventing platelet activation. These findings might indicate a diminished cardiovascular stress-reaction following pre-exposition to polyphenol-enriched diet.
Thomas Nickel, MD, Med. Klinik und Poliklinik I, Campus Großhadern, Marchioninistr.15, DE -81377 Munich, Germany; Tel.: +49+89 44007 0; Fax: +49+89 44007-3100; E-mail: tsnickel@web.de.
T
T
Nickel
K
K
Lackermair
J
J
Scherr
A
A
Calatzis
M
M
Vogeser
H
H
Hanssen
G
G
Waidhauser
U
U
Schönermark
H
H
Methe
S
S
Horster
U
U
Wilbert-Lampen
M
M
Halle
D000328:Adult; D050197:Atherosclerosis / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D015539:Platelet Activation / Q000502:physiology*; D010974:Platelet Aggregation; D059808:Polyphenols / Q000494:pharmacology*; D011446:Prospective Studies
D059808:Polyphenols