Green tea reduces LDL oxidability and improves vascular function.
OBJECTIVE
Several different epidemiological studies have examined the association between the consumption of tea and coronary heart disease. Some, though not all, support the view that tea or flavonoids reduce the risk of cardiovascular heart disease. The aim of this study was to determine the short-to medium-term effect of a green tea extract on vascular function and lipid peroxidation as compared with placebo.


METHODS
The study was undertaken with 14 healthy women, none of whom were receiving any medical treatment. Measurements were made of antibodies and immune complexes by ELISA, endothelial dependent vascular function by Doppler ultrasound, and the concentration of oxidized LDL by TBARS.


RESULTS
The mean diameter of the brachial artery following the post-compression hyperaemia phase rose significantly (p < 0.0001) after treatment with green tea extract. Flow-mediated brachial artery vasodilation ranged from 5.68% for the placebo phase to 11.98% after the green tea extract (p = 0.02). The consumption of green tea extract was associated with a significant 37.4% reduction in the concentration of oxidized LDL (TBARS) (p = 0.017). The levels of anti-oxidized LDL IgM antibodies fell significantly after treatment (p = 0.002).


CONCLUSIONS
This study found that consumption of green tea extract by women for five weeks produced modifications in vascular function and an important decrease in serum oxidizability.
Tinahones
F J
FJ
Servicio de Endocrinología, Hospital Clinico Virgen de la Victoria de Málaga, Spain. fjtinahones@terra.es
Rubio
M A
MA
Garrido-Sánchez
L
L
Ruiz
C
C
Gordillo
E
E
Cabrerizo
L
L
Cardona
F
F
D000328:Adult; D000936:Antigen-Antibody Complex / Q000097:blood; D001916:Brachial Artery / Q000187:drug effects*; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002784:Cholesterol / Q000097:blood; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008077:Lipoproteins, LDL / Q000097:blood*; D010936:Plant Extracts / Q000494:pharmacology; D013662:Tea; D014280:Triglycerides / Q000097:blood; D014664:Vasodilation / Q000187:drug effects*
D000936:Antigen-Antibody Complex; D008077:Lipoproteins, LDL; D010936:Plant Extracts; D013662:Tea; D014280:Triglycerides; C099252:oxidized low density lipoprotein; D002392:Catechin; D002784:Cholesterol; C045651:epigallocatechin gallate