Milk May Strip Tea of Antioxidant Benefit

27 Sep 2012
World Tea News

BERLIN, Germany

Tea drinkers mainly seeking its many cardiovascular health benefits should keep milk from their brew…but don’t let it steal the joy you find in your cup.

European researchers, whose work was first published in The European Heart Journal, in October 2007, discovered that adding milk strips tea of some of its health benefits.

A study published this year looked at whether the effect was limited to dairy products. It was not: Proteins in soy milk had the same effect as regular milk on antioxidants in tea.

“Simultaneous ingestion of dietary proteins reduces the bioavailability of galloylated catechins from tea in humans,” researchers concluded. Participants added 10% milk by volume to black tea.

In the 2007 study researchers had 16 healthy adults drink cups of freshly brewed black tea, black tea mixed with a small amount of skim milk, or boiled water. Then the scientists measured the effects on vascular function.

Compared with water, black tea “significantly improved” arterial function, the researchers found, “whereas addition of milk completely blunted the effects of tea.”

The scientists repeated similar tests in mice and found the same results, which they speculated may be a result of proteins in milk binding to and neutralizing antioxidants.

“Milk,” the researchers wrote, “counteracts the favorable health effects of tea on vascular function.”