Seems like tea break times are over for those who prefer relaxing with a good cup of tea, with milk, of course.

A study conducted by researchers from Charite Hospital Universitatsmedizin in Berlin, Germany and published in the European Heart Journal, has come out with a study that shows adding milk to your tea may nullify the heart protective effects of tea compounds.

Tea is known to contain flavonoids like catechins, which protect the heart and have anti-cancer effects as well.

The study which involved 16 post menopausal women was performed by measuring levels of FMD (flow mediated dilation) on ingestion of black tea, black tea with 10 percent skimmed milk and plain boiled water, as a control.

Blood flow when on the rise, causes blood vessels to relax or dilate. Tea-derived catechins have the capacity of increasing blood flow, by the production of a chemical called nitric oxide.

The FMD levels of the women, measured via ultrasound, were found to increase with consumption of black tea, and found to decrease when milk was added to the tea.

These experiments were also repeated on laboratory rats and similar results were observed.

Senior researcher Dr Verena Stangl, professor of cardiology at the Charite Hospital says the reason could be that caseins or proteins found in milk reduce the level of catechins, as the milk reacts with tea.

She concludes, "Our results thus provide a possible explanation for the lack of beneficial effects of tea on the risk of heart disease in the UK, a country where milk is usually added."