Objective: Firstly, to study the effect of tea and tea polyphenols on cardiovascular risk indicators of the inflammatory system (IL6, IL1beta and TNF-alpha, CRP), and on haemostasis and endothelial proteins with an acute phase behaviour (fibrinogen, vWF, PAI-1, FVIIa and u-PA). Secondly, to study the relationship between plasma levels of antioxidants (alpha-tocopherol, beta-carotene and vitamin C) and these acute-phase, cardiovascular risk indicators.
Design: Randomized study.
Subjects: Sixty-four smoking healthy volunteers were recruited by newspaper advertisements; there were five dropouts.
Intervention: Four-week administration of black tea, green tea, green tea polyphenol isolate and mineral water ( 13-16 per group).
Measures: Plasma levels of the inflammatory markers IL6, IL1beta, TNF-alpha, CRP, fibrinogen, vWF, PAI-1, FVIIa and u-PA and of the antioxidants alpha-tocopherol, beta-carotene and vitamin C.
Results: Different dosages of tea polyphenols had no effect on inflammation, haemostasis and endothelial markers. There was a significant negative correlation between the levels of the antioxidant beta-carotene and the inflammation markers IL6 and fibrinogen (r = -0.35 and r = -0.37, respectively, P<0.01) in this group of smokers. Remarkably, there was a significant positive correlation between the levels of the antioxidant alpha-tocopherol and the inflammation marker IL6 (r = 0.28, P<0.05).
Conclusions: Tea drinking had no effect on the levels of the inflammation, haemostasis and endothelial cardiovascular risk factors measured. We did observe a relationship between the antioxidant variables alpha-tocopherol and beta-carotene and inflammation markers in this group of healthy smoking subjects.