Milk in tea may affect heart

BERLIN, Jan. 9 (UPI) -- Tea drinkers should hold the milk if they want to protect themselves against heart disease, German researchers said.

When drunk without milk, black tea seemed to improve cardiovascular function, researchers from Charite Hospital Universitatsmedizin Berlin said. However, they said adding milk counteracts beneficial effects tea may have in protecting against cardiovascular disease, the Independent reported Tuesday.

Proteins called caseins could be the culprits, researchers said.

The research, published in the European Heart Journal, studied 16 healthy post-menopausal women given just black tea, black tea with 10 percent skimmed milk or boiled water as a control.

They drank it on three separate occasions but refrained from drinking tea for four weeks both before and after the study. All women were given a croissant as a standardized breakfast while they drank the tea.

The researchers measured whether blood vessels in the artery could relax if the blood flow increases, a condition called flow-mediated dilation. They did this before tea was drunk and afterward at intervals.

"Black tea significantly improved FMD in humans compared with water, whereas addition of milk completely blunted the effects of tea," researchers said.