It has been known that tea has many health benefit like prevention of heart disease, protection against cancer and it has some calming effect can make us feel more relax.

But these valuable effects that tea offers may become useless if you add milk to it.

According to researchers from Germany, who wrote an article in the European Heart Journal, because of their new findings about milk, an immediate study must be made on the effect of tea on cancer prevention.

One of the authors, Verena Stangl, a professor of cardiology at the Charité hospital in Berlin said “Since milk appears to modify the biological activities of tea ingredients, it is likely that the anti-tumour effects of tea could be affected as well.”

The researchers suggested that tea drinkers who usually add milk should drink it black for some of the time.

Catechins, which are the flavonoids in tea, are said to be the reason for its health benefits especially on the heart. The research, however, found that caseins, a kind of proteins in milk, interacted with tea to reduce its catechins level.

The study showed the effects of drinking black tea, tea with milk and plain hot water on 16 women volunteers. The result is that after drinking black tea, there was noticeable dilation of the blood vessels as tests were conducted on the brachial artery of their forearms for two hours.

And according to the lead author Mario Lorenz, who is a molecular biologist, the addition of milk completely prevents the biological effect from happening.

The authors said, these could probably be the reason why Britain doesn’t seem to enjoy the protection from high rates of heart disease despite being a nation of tea drinkers.  Most probably because milk is usually added to its tea.

This research emphasizes the importance of the interaction of food but also and that having a cup of tea can be helpful if it can make people feel more relax, according to June Davison, a cardiac nurse at the British Heart Foundation.

She also added that taking regular exercise, avoiding smoking and eating a healthy balanced diet will help protect your heart health more than leaving milk out of your tea.