Milk's Effect on Tea's Antioxidant Levels
March 24/Health & Medicine Week -- According to a study from Oxford, U.K., "Epidemiological studies have shown that populations consuming fruits, vegetables, tea, cocoa and red wine have lower incidences of cardiovascular disease, certain cancers and eye disease. These health effects have largely been attributed to the polyphenol content of the foods and drinks studied."
"Black tea is rich in a range of polyphenolic compounds that could potentially have health-promoting properties. The scale of consumption of tea in the U.K. means it could be an appropriate vehicle for increasing the antioxidant activity and polyphenol content of human plasma. However, it is common practice in the U.K. to add milk to tea, and some studies have suggested that this may decrease the overall antioxidant capacity.
"The objective of the present study was to analyze and compare the antioxidant capacity of five brands of tea and to test the hypothesis that the addition of different volumes of whole milk, semi-skimmed and skimmed milk may affect the antioxidant capacity. Each of the teas analyzed was a significant source of antioxidants. The addition of 10, 15 and 20mL of whole, semi-skimmed and skimmed bovine milk to a 200mL tea infusion decreased the total antioxidant capacity of all the brands of tea. Skimmed milk decreased the total antioxidant capacity of the tea infusion significantly (P<0.05) more than either whole milk or semi-skimmed milk," wrote L. Ryan and colleagues, Oxford Brookes University.
The researchers concluded, "Black tea is a valuable source of antioxidants, and the effect of milk on the total antioxidant capacity may be related to the fat content of the milk."
Ryan and colleagues published the results of their research in Nutrition Research ("Addition of Whole, Semi-skimmed and Skimmed Bovine Milk Reduces the Total Antioxidant Capacity of Black Tea." Nutrition Research, 2010;30(1):14-20).
For additional information, contact L. Ryan, Oxford Brookes University, Sch Life Science, Funct Food Center, Oxford OX3 0BP, United Kingdom.
From the March 29, 2010, Prepared Foods E-dition