I’ve heard that adding milk to tea kills all the antioxidants. True?
Adding milk does decrease the antioxidants in tea, but in varying amounts.
Proteins in milk can bind to the tea polyphenols thus decreasing their antioxidant capacity. One analysis of the studies that looked at the phenomenon found an antioxidant reduction of up to 18% depending on the type and amount of milk used. And, in a 2013 European Journal of Nutrition study, researchers examined the levels of catechin (a type of antioxidant) found in green tea when drank by itself or with skim milk, soy protein or casein protein. A significant reduction in the bioavailability of catechins was found in the protein groups, compared to green tea alone.
In all the studies, people who drank tea – with or without milk – received some sort of benefit from the tea antioxidants. So if you really love tea with milk or cream, by all means keep drinking it that way.
If you want to squeeze the maximum possible health benefits out of every cup, then ditch the milk.
And while you’re at it, ditch the tea bag and use loose-leaf tea. One analysis found that using tea bags gives away between 5% and 50% of the total antioxidant capacity of the tea, suggesting that some tea bag materials can counteract the absorption of flavonoids in tea.