How long does good tea last?

I recently cleaned out my tea cabinet. I moved along a gaggle of random mugs I hadn't used in years. I gathered stray packets, bags and samples into a sencha-colored tin. Most importantly, I trashed a lot of old tea. I mean, really old. There were some Lipton bags in there someone had given me two houses ago (thanks so much, I'll put them right up here...), and a dwindled pouch of Nepalese Darjeeling a friend had sent me from San Francisco back in at least 1999. Freshness matters, after all, no matter how pretty the calligraphy on the box might be.

One of the features now at World Tea News is about just how necessary this kind of cabinet-cleaning might be. Could I still have brewed that Darjeeling and stomached it, or gotten any of the usual health benefits from it? A recent article in the Journal of Food Science covers a study saying that green tea's beneficial ingredients only remain stable for six months. (Freshness matters, indeed!) The World Tea News story, the first of two parts, starts from there and offers a few different viewpoints.