HEALTHEFFECTSOF BLACK TEA AND THE IRMODULATION BY MILK

Abstract

There is a very long history of association of teawith health; it evolved fromdomain ofmedicine
in ancient China to its current global status of beverage having the largest consumption after
water.While there is a strong epidemiological link of tea consumption with the risk of cancer
and heart diseases, the causal relationships are just beginning to unravel. Flavonoids are
one of themost active ingredients in tea.Both the nature and amount of flavonoids available
to human body after the consumption of tea, therefore, become critical in defining the efficacy
of tea. Multiple factors which govern bioavailability of flavonoids include quantity and quality
of available flavonoids in tea, genetic characteristics of tea consuming population, themanner
(brewing vs. boiling) in which tea infusion is prepared, and perhaps also by whether or not
milk and the amount of milk is added to tea. The addition of milk may have significant
implications in bioavailability of tea flavonoids in south Asia where tea infusion is mostly
prepared by boiling (in comparison to brewing) tea leaves in presence ofmilk for time ranging
fromfewto severalminutes. In the absence of any significant epidemiology or clinical study
fromthe region, the supporting evidence for public health contribution of tea relies on the
evidence derivedmainly fromwestern countries for black tea and Japan and China for green
tea. In this article, we reviewthe relevant literature available on influence ofmilk on the health
effects of tea. The available literature indicates that amount of milk in tea, if kept below
25%, does not significantly affect bioavailability of catechins in blood plasma. Though milk
may delay the time taken to raise plasma antioxidant potential, the levels still reach significantly
higher to that of baseline.There is a need, particularly in SouthAsia, to initiate further studies
to generate data, which at this time seem insufficient for any evidence based nutritional
recommendation on addition of milk to tea especially when the amount of added milk is
high.