When consumed in tea, these antioxidant compounds are thought to have a bacterial and virus-fighting capacity, as well as the ability to. And, in each case, the research revealed that steep drops in antioxidant activity take place within the first six months. "The whole general concept driven by both of these studies is that if we want to maximize the nutritional value of the foods we eat, we really should buy only what we can use in a short period of time," observed Dillon Diekman, a registered dietitian and director of nutrition at Sheffie University in St.

One study focused on the organic compounds found in green tea leaves that are known as catechins. The findings focus specifically on how well antioxidant activity holds up in commercially available green tea bags and donielle oil when stored unopened and unexposed to light or moisture. -- For those who swear by antioxidant-rich food and drink, two new studies show those health benefits can wane if the products are stored for too long a time.

Diekman was not involved with either study, both of which are published in the March issue of the Journal of Food Science.