The outcome of a experiment is the result
Keeping in mind a total ignorance of both the health benefits of these teas, and the interaction between milk and antioxidants, I believe that it is possible that milk could hinder these benefits.
Tea is usually a hot beverage. Milk, when added to this beverage, would easily dissolve. When a solute (milk) dissolves in a solvent (tea), the chemical properties of the resulting solution can become quite distinct from both of the original substances. It seems possible that the same chemical properties of tea that make it healthy could be altered by the addition of milk.
C6H6(l) + 6 Cl2(g) = C6Cl6(s) + 6 HCl(g)
