The molecules of which foods are made are too large to pass through the lining of the digestive system. Digestion results in the formation of smaller molecules that are able to pass through that lining and enter the person's bloodstream. (for example,) Sugar molecules formed by the digestion of starch enter the bloodstream.
Either way, not worth the risk - you can get very ill from consuming or drinking expired products, including ice tea. Now if it is a best before date, that tells us something else. It says it has not turned or gone bad, but that it may not taste very fresh after the date on the bottle. There is a huge difference between the comments expired and best before - so please use caution and consider these points. For dry ice tea mix, you usually see a best before date.
Refrigerator iced tea is smooth without bitterness, and it's easy to make. It's safer to drink than sun tea and you get all of the cancer fighting health benefits found in tea. Ingredients. 4 tea bags or 4 teaspoons loose leaf tea.