You receive more antioxidants from freshly brewed tea than from other types of drinking, such as quick tea and decaffeinated tea. Ideally, green tea should be steeped for five minutes or more for maximum antioxidant benefits.
The majority of people in most nations drink their tea hot after buying it in cardboard tea boxes. There is an exception in America, as 85% of the country's tea is iced. A common problem with iced tea is that it usually has fewer catechins than hot tea. It has to do with how glazing tea is made.
When making iced tea, boiling water is usually added to tea. When the tea is cooled for about 5 minutes, the fluid is cooled by adding water to double its volume and then cooled.
Water dilutes the catechin content. If you want your iced tea to have the same antioxidant level as hot tea, add 50% more tea to the boiling water than you would normally.