Bioavailability of Catechins From Tea: The Effect of Milk by van het Hof KH, Kivits GA, Weststrate JA, Tijburg LB.
Unilever Research Vlaardingen, The Netherlands.
OBJECTIVES: To assess the blood concentration of catechins
following green or black tea ingestion and the effect of addition
of milk to black tea. DESIGN: Twelve volunteers received a single
dose of green tea, black tea and black tea with milk in a
randomized cross-over design with one-week intervals. Blood samples
were drawn before and up to eight hours after tea consumption.
SETTING: The study was performed at the Unilever Research
Vlaardingen in The Netherlands. SUBJECTS: Twelve healthy adult
volunteers (7 females, 5 males) participated in the study. They
were recruited among employees of Unilever Research Vlaardingen.
INTERVENTIONS: Green tea, black tea and black tea with semi-skimmed
milk (3 g tea solids each). RESULTS: Consumption of green tea (0.9
g total catechins) or black tea (0.3 g total catechins) resulted in
a rapid increase of catechin levels in blood with an average
maximum change from baseline (CVM) of 0.46 micromol/l (13%) after
ingestion of green tea and 0.10 micromol/l (13%) in case of black
tea. These maximum changes were reached after (mean (s.e.m.)) t=2.3
h (0.2) and t=2.2 h (0.2) for green and black tea respectively.
Blood levels rapidly declined with an elimination rate (mean (CVM))
of t1/2=4.8 h (5%) for green tea and t1/2=6.9 h (8%) for black tea.
Addition of milk to black tea (100 ml in 600 ml) did not
significantly affect the blood catechin levels (areas under the
curves (mean (CVM) of 0.53 h. micromol/l (11%) vs 0.60 h.
micromol/l (9%) for black tea and black tea with milk respectively.
CONCLUSION: Catechins from green tea and black tea are rapidly
absorbed and milk does not impair the bioavailability of tea
PMID: 9630386 [PubMed - indexed for MEDLINE]
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