Adding Milk Doesn't Diminish Black Tea's Healthy Chemistry
June 8, 2007 -- Adding milk to black tea -- as most Britons prefer -- doesn't rob your cup of healthful polyphenols, Scottish researchers find.
Drinking black tea seems to lower a person's risk of heart disease and cancer. Some researchers have suggested that milk may react with the polyphenol compounds in tea, thereby diminishing their healthful effects.
That would be bad news indeed to residents of the British Isles, who prefer a spot of milk with their "cuppa." Can it truly be so? Janet A.M. Kyle and colleagues at the Rowett Research Institute and the University of Aberdeen, Scotland, decided to find out.
Kyle and colleagues asked nine healthy volunteers to drink a beverage on three different occasions. At one visit, they drank 10 ounces of black tea -- the equivalent of two British teacups -- with 3.4 ounces of low-fat milk. On the next visit, they drank the tea with added water. And on the third visit, they didn't drink tea at all, but had just milk and water.
At several time points after drinking their tea (or milk water) the researchers measured the volunteers' blood levels of various compounds from the tea.
They found that tea did indeed significantly increase blood levels of various antioxidant compounds -- and that the addition of milk did not lessen this effect.
Or, as Kyle and colleagues more properly put it, "Our results suggest that the formation of milk protein-polyphenol complexes does not compromise the antioxidant potential of the beverage."
The findings appear in the June 13 issue of the American Chemical Society's Journal of Agricultural and Food Chemistry.