A Single Dose of Tea With or Without Milk Increases Plasma Antioxidant Activity in Humans by Leenen R, Roodenburg AJ, Tijburg LB, Wiseman SA.
OBJECTIVE: To investigate the effect of black and green tea
consumption, with and without milk, on the plasma antioxidant
activity in humans. DESIGN: In a complete cross-over design, 21
healthy volunteers (10 male, 11 female) received a single dose of
black tea, green tea (2 g tea solids in 300 ml water) or water with
or without milk. Blood samples were obtained at baseline and at
several time points up to 2 h post-tea drinking. Plasma was
analysed for total catechins and antioxidant activity, using the
ferric reducing ability of plasma (FRAP) assay. RESULTS:
Consumption of black tea resulted in a significant increase in
plasma antioxidant activity reaching maximal levels at about 60
min. A larger increase was observed after consumption of green tea.
As anticipated from the higher catechin concentration in green tea,
the rise in plasma total catechins was significantly higher after
consumption of green tea when compared to black tea. Addition of
milk to black or green tea did not affect the observed increases in
plasma antioxidant activity. CONCLUSIONS: Consumption of a single
dose of black or green tea induces a significant rise in plasma
antioxidant activity in vivo. Addition of milk to tea does not
abolish this increase. Whether the observed increases in plasma
antioxidant activity after a single dose of tea prevent in vivo
oxidative damage remains to be established. European Journal of
Clinical Nutrition (2000) 54, 87-92
Unilever Nutrition Centre, Unilever Research Vlaardingen, PO Box
114, 3130 AC Vlaardingen, The Netherlands.
PMID: 10694777 [PubMed - indexed for MEDLINE]
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